Revisited: Is Honda’s K-Series Really the Greatest 4-Cylinder Ever Made?

Welcome to High Performance Academies, tuned in podcast, I'm Andre your host.

We'll be taking a break over the Christmas New Year period and we'll be back in action

mid January. That means that although there won't be any new episodes for a few weeks,

we'll be taking another look at some of our favourite episodes.

This week we're going back to episode 105 featuring Terry Radborne from Born HPP.

Terry is a specialist in all things Honda K20 which is quite handy considering these

are one of my favourite engines and I'm going to be milking Terry throughout this

particular episode for all of the secrets to building a high performing, naturally

aspirated K20 for very selfish reasons. Obviously we have a K20 in our CRX

endurance car and I'm always looking for ways to improve the performance and

why reinvent the wheel. Terry's done just about anything and everything

you could think of on the K series platform so I'm going to be benefiting from

his experience which means so are you. Now not only is Terry an expert on the K series

platform but he has a really interesting backstory, particularly how he got into

engine building and he's worked for some really big names. Specifically he's worked

for Advanced Engine Research or AER. And this is a name that a lot of you may not

be familiar with but they build bespoke engines for the likes of LMP1, Le Mans prototype

cars just to name one of the categories they're involved with. They do all of their

in house development of the engine design, development, dyno testing etc.

And are also very closely linked to life racing, the specific ECU that they use

which also now just happens to be Terry's ECU of choice. Following on from this he also

did a stint with Mercedes F1 and it's not too often we get to talk to guests that

have experience at this level. And I will add a little caveat here, I'm sure everyone

can understand that working at one of the Formula One teams comes with a bunch of

NDAs. Obviously they can't talk about everything that they were involved with

during those times and you'll notice that during this interview Terry might seem

a little bit evasive on a few of the questions that I'm going to ask him.

My guess is that's for a very good reason and he can't talk about everything.

So let's just understand that and keep that in the back of your mind while you're listening.

Now let's get into our interview. Alright welcome to the podcast Terry, thanks for

joining us. Really excited to get into this chat from a selfish standpoint

because I'm ready to pick your brains on everything Honda K series but

before we get into it, let's find out about your background as we always do.

How did you get interested in cars, motorsport and engines in the beginning?

So yeah my background is really straight out of secondary school or high school.

Thrown into the deep end I started at a company called Advanced Engine Research

in the UK. They specialised in developing blank sheet engines for Le Mans

on 24 hour LMP1 and LMP2. We actually had the privilege

to tour Advanced Engine Research's facility or AER

as they're probably more commonly known and for those who haven't

heard that name before, AER is no joke. They are working

at the absolute cutting edge of engine development

and engine performance and developing bespoke clean sheet

of paper engines for particular high level professional motorsport

applications which really why we were given a tour but unfortunately

we were allowed to film anything in the facility. It was a bit of a waste unfortunately.

An exceptional facility. How do you just walk in the door

at Advanced Engine Research and get yourself a job? Surely there's

a few dots when missing along the way. So I think my granddad had a bit of a

play with that so he owned a machine shop that machined heads for Cosworth

and I think he had some link to Mike Lancaster who's the founder of AER.

So as a lot of companies in the UK work

I sort of had a leg up I suppose but also had the

experience to go in. I probably had three or four years of

looking over my granddad's shoulder CNC machine to start with

which was obviously quite a bit of experience for a 16 year old to already have.

So it was in and hit the ground running really.

So at this stage no formal qualifications probably

given your age but you've got that experience in watching your grandfather

obviously doing this high level machine work for Cosworth.

What was the job position when you started at AER?

What are you doing there? It was effectively an apprentice but we only had a

small team of guys at AER right in the early days so this is back in

2003. We had 16 guys to design, develop, build

dyno track support and make looms and

ECUs for Le Mans so it was just a 14 hour

day was quite usual and the odd all nighter in a month

was quite normal too so it was just one of the

effectively it was my university. It was the place where I just crowned

as much information and learned as much as I could as quickly as I could

and they had all of the facility and projects on

to do that so it was just a mega place to get my grounding and my first

entry into engineering. So if I'm sort of joining all of those

dots together correctly, you're getting experience on engine

development, so the engineering behind designing and developing an engine

I'm guessing here you're also getting involved with learning about

the calibration or mapping of the engines, harness development

and we're also going to talk a bit more detail about it but actually

they developed their own ECU which ended up becoming Life Racing

so pretty much anything to do with the powertrain itself

you had a hand in that. Yeah and I think also one of the biggest

fundamentals from AER at the beginning is there was no upstairs, downstairs

sort of regime. The big core of the first guys

that were in the business, there wasn't engineers versus engine builders

it was just one big team effort so in larger companies

that I've worked in and across the globe now, engineering would be very

much split from the shop floor but in AER in the early days

we would be assembling an engine, the designer would be stood there

helping getting nuts and bolts out the rack. The guy

that was about to map it would be sat in the corner creating a base calibration

looking at the engine himself and it was just a team effort

so it was easy to pick up skills in every department

very quickly. You could be out in machine shop at one moment

and off potting a sensor at the next like

it was just a team effort effectively which I think it doesn't really

happen in big businesses as much now. No I can imagine

that would be quite a unique scenario. Yeah it was just a mega

place to learn. Alright without getting into too many specifics

and I'm assuming there's a bunch of NDAs around your time at AER

I'm interested if you can give us some high level understanding of the process

that goes into developing an engine from a clean sheet of paper

and where I'm going with this is when you are

developing an engine from a production based factory engine

a lot of the designs are really constrained, the geometry

within reason of the engine, the components are already set

likewise you're dealing with a production cylinder head which yes you can modify but

obviously there are limitations compared with this clean sheet of paper approach

where obviously there will be regulations with a racing class

but so much freedom I figure it would be very easy

to kind of lose your way if you weren't careful and weren't

really understanding what the engine needed so can you give us some insight into how that

design process actually goes? Yeah I think

being involved in a few blank sheet engines now in my career

I think the more that you do obviously the more you understand the process

and I think every time now if I was to take or be involved

in a project like that again is to go straight back to the overview

the overview to make an efficient engine is to not give away

cheap energy, like you can't give away energy for free

so that is vibration, that is energy into the

cooling system, I think really one of the big fundamentals has always been

vibration so before you even start drawing

anything in CAD is to try and understand the harmonics

and what is going to go on in the chassis that you're developing the engine for

obviously everything that I've ever done from a blank sheet of paper

I've been involved in has always been stress mounted so critical speeds

of cranks, camshafts, all of that what I sort of call 1950s

physics all needs to be put in the cooking pot at the beginning

and the big fundamentals of what you're actually going to go and try and achieve

with it but I think yeah not designing everything

in a way to keep cranks away from critical speed, camshafts

away from critical speeds and not creating vibration

on a set engine is one of the key or starting features really

of the design. When you're talking about these critical speeds and the

vibration or harmonics are you talking here about making sure that you are

not operating at a resonant frequency for the component

where those harmonics are sort of amplified and more

likely to result in a failure or am I missing the point here?

Yeah so obviously when a crank is designed in F1 and an F1 engine

idles around 5 to 6000 rpm and the crank

will be designed in a way that all the critical speed is put right down

the bottom end of the rev range so it would normally be

on most crank shafts around 3 and a half thousand rpm obviously

the Mercedes F1 engine that I ended up being involved in

towards the latter part of my career rev to 18,000 rpm

so all of the bad harmonic that you're

ever going to get from any shaft in the engine is hidden in the point

that you're never ever going to see on track or in the garage so

even to the point if you watch an F1 engine warming up in the garage

the systems engineer will have a little blipper in his hand

and it will constantly be while he hit the cars up on the stands

it will constantly be blipping the engine and the reason for that is not to do an

elaborate Walmart pits to nullify the vibration and take the vibration out of

the back of the car because you have what's called 5 orders of vibration

so the first order if the first order keeps building and building

it can spread to the second order the third order then all of a sudden

components can get stresses on that you don't actually want them to

see or experience and that they don't experience on track

because the rate of acceleration of revs is so fast

you're constantly ripping through them energies and you're not letting them energies

from one component expand into another so essentially you want

to avoid holding the engine at a steady rpm

and that's you're always moving through those frequencies

yeah you're moving through them but also fundamentally when you

design the engine from scratch you try and put everything out of the way

so when the engine is actually on track and running there isn't any

critical speed of crankshafts or any component

and a lot of that work that I've done in my career on

vibration a blank sheet engine never happens from the first design

by the time a blank sheet engine goes racing you're normally

beyond engine version D or E so you would have started

with a much bigger heavier engine with a lot more meat on castings

and heads and you'll slowly work down and we've always used

real high level vibration diagnostic tools to

watch we can watch vibration in all five orders

so effectively before as you're leading up through the development

the engine will just get smaller and smaller slight designs

depends on crank counter weights a little bit more material there

a little bit off there and obviously a lot of it is

1950s physics and design but effectively real world

real world data at 1000 hertz on vibration sensors

paints the picture I think this is one of the big bits

is through the development stages if you're

data logging correctly so much can be worked out from the quality of

data nowadays or as obviously back in the day it was all

a little bit more feel and like adjust but nowadays

the data doesn't lie as they say so talking about back in the old days

I mean if you look back in the earlier days of

engine development for the likes of Formula One we didn't have

the sort of CAD tools that we've got these days and also the

ability for final element stress analysis for example

computational fluid dynamics none of that was done on a computer

back in the day the technology wasn't there how important

are those software tools for

validating a design of a new engine before any single component

is ever actually manufactured obviously it's always going to be much

much cheaper to design and test an engine in the virtual world

before you actually get to a point of manufacturing it for real

yeah I suppose actually when you look at the price of a modern day F1 engine

it's around a million pounds in components so actually

designing spending more time in CAD land and stress analysis

world is actually the more cost effective way because you're

effectively not wrecking a million pounds worth of engine but I think

the difference between stress analysis is still in its

development stages I would say you still have to keep feeding back

real world data and everything that works in that

world at the moment doesn't necessarily work in the real world just

yet obviously one thing that stress analysis can't really do

and when you get back into the orders of vibration you could be

sat on the mul sand straight at 6000 RPM

100% load and one part just

starts to put a second order or a third order into another

and that leads on to another and the way I sort of describe it is

when you imagine a drummer playing his drum set you know you've got

your first order which is the first big bass drum and if

he kept it in that hard enough the vibration would creep and before you know

that the cymbals are playing so some of that real world

stuff can't actually be simulated just yet so

the virtual world versus the real world and then slimming the engine

down as you get to the actual race spec you have to really

you can't just rely on one tool you have to sort of do everything

in stages so yeah effectively normally in a big engine

project like that you'll start with an engine on the dyno working out

combustion analysis and that engine will pretty much look like

it's come out of the tank you know it'll be a big robust piece

the internals are very much what you're going to end up with when you go racing

and you're developing, developing but casting

thicknesses and everything's massive

to begin with and then it just gets scaled down as it goes into the car.

So you've got that thick material casting for strength and reliability

for a development engine but obviously that comes at a weight penalty

which you can't have in a race application so it's about over the

development period of the engine kind of figuring out where that fine line

is between getting the engine light enough to be competitive but

obviously still having the reliability it needs. Yeah I think

and also the other bit is we obviously spend so much time on

engine dinos we have all of our vibration analysis on engine dinos

and we are actually the engine dyno ends up

being a lot harsher than what the engine experience is in the car

especially in F1 when you go and bolt four massive bits of rubber

around the engine and the harmonics of it

you've actually ended up with four massive dampers suppressing the

vibration. Sure yeah. So sometimes in the development

stages you can actually scare yourself quite a lot and probably

we end up developing on engine dinos a lot more

effectively than what we actually need when it ends up going

racing. There's a lot more vibration that obviously a lot

gets put into developing engine plates for engine dinos

but effectively you haven't got four bits of rubber bolted around it

and you can't get rid of the things that you'll get rid of in the actual car

so sometimes we've seen in the developments that I've been involved in

in certain engines we've seen scary moments on engine

dinos and had issues with engines that actually when we put the engine

in the car just don't exist. Sure. So a lot of the time

the same vibration analysis software that we've

used on the engine dyno for the first tests actually gets

bolted straight in the car and a lot of the scary numbers that we were seeing

on the dyno have just gone by the time it goes to the car.

So the dyno testing in that respect could actually

lead you to over engineer the engine which

in essence actually proves to not be necessary in the race application.

Yeah and I think especially when we was developing

engines with closed loop not control in the early days

especially on hard mounted engine dinos

we would start to see vibrations creep in and affect

the closed loop not control that didn't actually exist in the real world

and all of a sudden you put it in the car and you've been

developing to this real tiny window to try and get the engine

to work in and then the real world. That window gets a lot wider.

Yeah which is a nice place to be I suppose generally but...

Yes it normally goes the other way so yeah when you

get some advantages on the real world on the road or the racetrack then that's actually

a pleasant surprise. Always nice to take advantage of that.

You've kind of alluded to your work already in F1 which

obviously we don't get too many guests on here who have had hands on experience

in the F1 so I want to deal with that in a moment.

In terms of the engine development for both AER

and Mercedes F1 though, I'm interested were these

engines initially being developed as maybe a single cylinder test mule

to sort of do a proof of concept at a cheaper level

rather than developing an entire four cylinder V8

whatever it might have been and then once your sort of new year on the right path

kind of scaled up to the full number of cylinders

or were you all in right from the start with the complete engine design as intended?

Yeah now exactly that time at Mercedes before I

was there though was developing a single cylinder but the big thing

with AER is we obviously had decent budget but

we didn't actually have the budget to start the single cylinder stage. I think that is

when you go through this whole process if you can start the single

cylinder stage that's really the ideal place to start to develop

piston crown design and effectively even start

creating your base map from there. You'll have an idea of how efficient the engine is going

to burn and you can get a lot of data from that but not every

engine project that I've ever been involved with we've been able to start there unfortunately

pretty much in the AER days we'd sort of have V1 and

V2 and that's sort of what I've brought into what the work we're doing

at Bourne HPP we sort of start with a V1 and you've

got some ideas there and you end up with slight tweaks

on pretty much every component and then it's normally V2 that we end up going

racing with so. Yeah okay yeah that makes sense. Now in terms

of internal combustion engines they are incredibly wasteful

most of the energy from the fuel that we're burning is sort of

going out of the engine in terms of heat and sound and only a modest

amount is actually being turned into mechanical energy. So

when we're dealing with a production engine there's not a lot of levers that we

have available that we can pull to really swing

the sort of tide in terms of gaining back some of that

efficiency. When you're dealing with an engine designed from scratch

what flexibility have you got in the design to improve the

efficiency? Basically how much of the energy of the fuel you're actually turning into

power at the crankshaft? Yeah I mean like going back to where we started

a lot of the work that I've been involved with has all been around vibration

because vibration is just wasted energy and effectively then wasted

fuel. You've had to burn that fuel to create that vibration

so I think a lot of the work that I've done is really

trying to nullify vibration and take it out of the engine entirely.

So that vibration just to break that down not only are you talking

about something that could potentially be damaging to the engine component

but as you're mentioning here it is also wasteful because some of the

energy is being used to create those vibrations. Yeah exactly that and

yeah as your order builds up and vibration across the

engine package just more and more energy starts to get

wasted so trying to design components to effectively

run at order one or two and not ever see orders

three four or five is what you want to try and achieve really

to try and make the engine as efficient as you can. How about in terms of

thermal efficiency I mean you know in the aftermarket we see things like

thermal barrier coatings for the tops of our piston crowns even

the inside of the combustion chamber as well. Yeah have you got

any input on elements of improving thermal efficiency? Yeah

there's obviously a lot of coatings that I've played with in my

career to do that from a friction loss point of view and also as

you say from a thermal point of view unfortunately I don't think I'm allowed

to talk about some of the coatings that I've seen. I think that's probably just

stepping a little bit too far. Yeah fair enough. Suffice to say

I'm guessing if I'm allowed to talk about them they're effective. Very effective.

In terms of efficiency and economy I mean economy is

something we don't really think about too much in a race application particularly

for a sprint race but you know endurance racing and particularly for a 24-hour

race economy is incredibly important and it can

mean the difference of a pit stop or more over the length of a race.

And I think in the aftermarket, enthusiast market

we're used to tuning at sort of lambda targets maybe in the range

of .80 for turbocharged engines maybe .85 through

to maybe .90 or thereabouts for naturally

aspirated engines. In the lights of the morn

as I understand it, it's pretty common to be on the other side of

Stoik with your tuning even with turbocharged applications. Am I on the

money there? Definitely. I think one of the biggest innovations in motorsport

and globally is obviously being direct injection. You've just

not got as much wasted fuel and you can effectively

have a much more cleaner burn as what we call it. You can control

the flame front a lot easier and obviously there's been

not going too in depth but there's been so much work done even on

injector angle and I think obviously piston design.

It's not just one part, it's the whole bit and I think the big fundamental

that I get back to always on engine efficiency is airflow

like the big overview on all of this is we've got direct

injection, we've got this but understanding the airflow of your engine

and not wasting or stalling air is really

how you pick up massive efficiency gains. Obviously the big bits

with like a straight 4 engine for instance is once you can understand

engine scavenging and not creating a secondary pulse in the exhaust

once you can understand pulsing. I think I've actually seen

a few of your posts where you guys have had exhaust gas pressure

sensors and you've had sensors post butterfly

so what we're doing the development stage once we've

got vibration out of the way effectively is actually map the airflow through

the engine. With some turbo applications you obviously

want to stall the air so creating a piston shape that

actually stalls the air on top of the piston for an amount of time to

actually cleanly burn all of the particles of air that you've managed to get into

the engine through the inlet valve that obviously increases efficiency

so the big overview without going too in depth and getting

myself in trouble really is airflow and once

obviously the sensors that we have at that level are a thousand

times a second measurement of airflow or higher

and the actual data that you see in the dyno cell will show

you what the airflow is doing. You've just dropped a number of

pretty technical elements into conversation there

and I just want to come back at a step so I mentioned tuning

on the lean side of Stoic which for the enthusiast market we don't

generally do and if we're talking about economy at cruise in a road

driven car, typically we look at a production car, it's going to be

sort of gently moving backwards and forwards across the Stoic air fuel

ratio 14.7 to 1, lambda 1.0 and most people think that

that's for efficiency and economy, the reality is that that makes

the catalytic converter work which gives good emissions which

for an RE production engine is really the be all and end all, if it doesn't meet

emissions requirements, all bets are off. So if we take the tuning

outside of the emissions regulations, we

can see an improvement in fuel economy by tuning

leaner than Stoic and I'm talking still here about cruise conditions.

The limitation sort of comes in at some point as we go leaner and leaner

particularly with a port injected engine, we get to a point where we can't

reliably light off the fuel air charge, basically

it just gets too difficult to reliably ignite it and we start running

into problems with misfire. So when you talked about the direct injection

here and sort of the airflow, joining again connecting these dots

if I'm getting this right, you're talking about basically managing

the sort of fuel air charge so you've got a rich enough fuel

air charge around the spark plugs so that it can be reliably ignited

even when the overall air fuel ratio is lean.

Yeah, effectively and I think obviously the big word in all of this is atomization.

It's how efficiently can you split the

fuel particles and mix them quite quickly with the air

and obviously split the particles into the air.

So many inefficient engines end up with big blobs

of fuel especially port injection engines, big blobs of fuel running down

and you would actually see with a fast lander reading you would see

your combustion waving effectively. The atomization

just isn't as pure as what you can effectively get to

with direct injection. Let's just talk about that element for a moment

then on its own because again we're getting into sort of areas here which we haven't

discussed on the podcast and I think it's sort of areas where these misconceptions

and misinformation, I think most people casually interested

in fuel injection and tuning would think that we

get this nicely atomized mist of fuel being delivered by our port fuel

injector and that goes into the combustion chamber and it burns beautifully.

The reality is somewhat different because

we've only got a modest period of time with a port injected engine

where we will be injecting fuel with the inlet valve open. Obviously the intake

valve is going to be closed for a reasonable period of the engine's operation

so with that in mind once we're sort of up in the

injector duty cycle range at some point we will be injecting fuel against

the back of a closed valve which on face value seems completely

counterintuitive. The reality is at least as I've sort of

studied it, seen it and understood it is once the engine is actually

at operating temperature the port wall is obviously hot, the back of the valve

is hot so when we're spraying the fuel and it's sitting on that port

wall on the back of the closed valve, it actually vaporizes and then

when the intake valve opens on the next intake stroke

we're actually ingesting fuel vapor as opposed to atomized

fuel, the vapor being easier to burn even compared to

finely atomized fuel. Yeah, exactly and obviously the direct injection

gets around losing fuel on the inlet valve

and like a lot of misconception I think from experience that I've

had is a lot of people back in the old days went to polish

ports and actually what a polished port does with a

port injector is you end up with as I was describing before these big

blobs of fuel and your burn's just not consistent so

when you are trying to target these much leaner lander

targets you need to make sure that your fuel delivery is exactly

the same every time and obviously that is really the fundamentals of

direct injection. Your consistency of fuel delivery

is absolutely perfect or as perfect as it's going to get and

going back to port injection there's just the delivery

just isn't the same. You end up with sometimes it's perfect and you

meet your lander target, sometimes a big blob of fuel runs down your

polished port. Obviously this is work that I've done outside of

big companies but I am a firm believer in the golf ball effect

on port injection. We've seen some real big movements

with the golf ball effect and the golf ball effect is effectively having

the dimples that you would see on the golf ball impregnated into

or machined into the port wall and what that does is create

a little pocket of air in every dimple and in the air can just

perfectly flow over the top but then we've also seen that with

the problems that we would have with port injection and fuel sticking to the walls

of the port this actually helps the fuel to get ingested by the engine

and not stick and gives you a more efficient and burn effectively.

Couple aspects I just want to come back and talk about there. Just about

port injected engines with fuel basically forming

I think you mentioned globules basically pulling out and then dripping into the

cylinder and again I think the misconception here is that's not happening

well it absolutely is irrespective if you've got a perfect sort of

mirror smooth port wall. There is always going to be some

level of fuel pulling out on the port wall. This is one of the reasons why

we need transient enrichment compensation in our ECUs

so that as we're changing throttle, butterfly angle

which involves changing the air speed and also importantly the manifold

pressure in the port that affects the amount of the fuel mass

that forms that pool of fuel on the wall. It's always being topped

up by the injector and then at the same time dripping into the cylinder but that key point

there, dripping into the cylinder, the fuel in that form is not really easily

combustible so it's kind of a bit of a waste. So there's that element there

but importantly I just want to dig into this golf ball or dimple port

effect because every time we post anything about this, we get

slammed with a lot of people thinking this is super controversial.

I'll admit I don't really have a dog in this fight and I haven't

actually seen any solid results back to back with a conventional

CNC port versus a dimple port, what that looks like on a flow bench

and then most importantly what that actually looks like on the dyno.

And we know that the flow bench numbers for head porting don't always

directly correlate with real world results on the dyno so

have you got that sort of data, can you give us some insight into what that looks like?

So when it comes to cylinder head flow benches

it's really not something in my career that I've really got

or spent too much time with so effectively we would design

a cylinder head or we would make a new port at Bourne HPP

and we would basically put it on the flow rig just to get a rough number

you know any time we see around 300 CFM generally

we're fine, a lot we start moving onto the engine and obviously

the experience that I've got like we touched on before

with actually looking at pressure sensors across the engine air flow

and if you want to go to the next level having an in-cylinder pressure

sensor so we would have a pressure sensor after the

we would have in-cylinder pressure sensor and in a sensor or sensor

in every exhaust bolt and then you can really map out what the air flow is doing across the engine

in my experience the old school way of using

head flow rigs with sort of past that that's just a generally

a check for us especially if we've created a new port shape

and done some of the porting by hand we would use a flow rig to just

make sure on a Honda for instance all four of our ports are

roughly flowing the same and we haven't had any issues with the machine inside

so that's really just a check but the proper work now

is actually done at Bourne HPP on the engine dyno and watching

air flow through the engine I think coming back to that port injection

efficiency and really getting the atomization to work the big

bit that we haven't touched on is secondary injection so everything that I've done in my career

with NA and turbocharged engines we've always had two stage

injection effectively so we've had one injector quite close to the inlet

valve in the in the trumpet we've had that at low speed so we'd use that

to fire the engine up and generally around three and a half thousand

four thousand RPM we start to blend to the set of

injectors that we have at the end of the trumpet and obviously running an injector

at the end of the trumpet really encourages the atomization

so it really helps you to blend the fuel perfectly

with the particles of air and in my mind

I always see the particle of air and the fuel attaching and it sort of

goes down in their little partners two by two into the

air and that's really where we want to get to I suppose it's my analogy in my head but

Yeah that makes perfect sense. There's a couple more bits I want to

talk about on that but before we kind of get sidetracked just coming back to the

dimple port versus conventional do you have any kind of dyno numbers

you know even kind of a rough rule of thumb of what you'd

expect from the improvement? So I think you can get

too engulfed in the actual air flow of the port I think

going back to the secondary injection and the atomization as an overhaul

an overview if you look at the atomization of the fuel

and creating a very powerful effective engine or efficient engine

if you can get the atomization right the air flow isn't as critical

the two are the same effectively

if you can mix your air with your fuel properly and actually

have a decent flow but I just think a lot of people get stuck on

flowing cylinder heads to try and produce power but that's

like an engine builder thing to do but when you've been involved

in all aspects you understand actually I need a really effective

efficient burn to create power and make an efficient engine

and obviously what we touched on before I need an engine that doesn't vibrate

and doesn't go past all the two of vibration and when you add

all of these aspects in you really your mind comes away from the

head flow rig I think you start touching on so many other areas

and obviously exhaust length is

such a critical thing and we touched on it earlier

Ultimately you can't consider any element of a competition engine

in isolation it is the sum of its parts

so you need to consider every element and make sure that they're all working in harmony

otherwise you're kind of dead in the water I believe

Just coming back again to port injection versus direct injection

you've sort of talked about this atomization using secondary injection

maybe outside of the inlet trumpets to make sure I think what you're getting at here

is the atomization is important but you've sort of talked about the mixing of the air

and the fuel so getting what I'd refer to as a homogenous air fuel mixture

which simply means that once the air fuel charges inside of the cylinder

basically no matter where we are inside the cylinder we've got the same

air fuel ratio again I think that's an assumption but

it's not always the case. Now that's great

however coming back to what I was talking about with lean burn before

with a homogenous charge once we get to a lean air fuel ratio

at some point we start running into problems with reliably

igniting that off and again I'm sort of stretching a little bit

outside of my own experience that we'll hear but at least I do a lot of reading

as I understand it with direct injection. We can design the injection

around a stratified charge design where

instead of having that homogenous air fuel ratio where everywhere in the cylinder

the air fuel ratio is the same, we can actually purposely design

a richer air fuel ratio kernel around the spark plug which will promote

better combustion, ignitability and then elsewhere in the

combustion chamber we've actually got a much leaner air fuel ratio so the overall

air fuel ratio is quite lean yet we're still getting reliable combustion

am I on the money with that? Yeah so there's obviously a lot of

tech that I can't touch on spark plug tech in the higher

levels and yeah sort of splitting the spark charge

across the cylinder and making sure that we ignite all four corners

of the piston is critical but also piston shape

and design so you know this isn't really, I'm not really given

too much of a way here to say you know the bold piston was designed

or really come to market in the Group B rally days and the whole

bold piston design as much as we're trying to lose compression

ratio in a turbocharged engine the actual bold design is

to actually still the air and create a sort of

sweeping air mixture on top of the and try and

force the combustion as far to the center of the pistons you can

so effectively when you want to go to these lean burn states

and you want to start running over lambda one there's so many parts that come in

but actual piston design and shape on top of the crown

is fundamental. Can you give us some indication when we're talking about

leaner than lambda one what sort of targets are you actually using

in an endurance turbocharged Le Mans engine if you can?

So I always go back to component control it just

depends what's going on and what scenario of the race that you're in but

we'd always have lean burn strategies we'd sometimes have component

control strategies which effectively sometimes

you just want to start laying some carbon on top of the piston so

go back to the big overview it's very hard to

have detonation if you're constantly laying a layer of carbon

one after the other so the perfect map engine has that

lovely grey layer of carbon on and what that generally means is

that you're laying a layer of carbon on your flame front and then you're

burning it off you're relaying and burning off and some stages

we might know from knock or we might know from very

oil and cylinder pressure sensors that we're starting to lose our

carbon front and that we can't run to these lean lambda targets

or there might be something else going on in the engine's health and we would

come back to a component control map or a much richer burn

but generally if the engine health is right and we're not

in the 24th hour of Le Mans we can generally run

with DI we can run over lambda one.

At that point is it safe to assume that you are giving away

a little bit of power in sort of sacrificing that for the

benefit of improved fuel economy? Generally if we sort of

take a conventional road car engine and we literally held it at

6000, 7000 RPM and we just did a sweep of lambda from

let's say 0.70 through to 1.1, we're going to find

that it's going to make peak power, let's say at 0.85,

maybe 0.90 and either side of that the power's going to drop away.

Am I right in assuming that there's no magic here and we see a similar

kind of relationship between power and lambda targets

in a purpose built race engine? Oh for sure yeah and obviously the big

overview to come back to the car as a whole is weight.

So a lot of the time you may not carry as much

fuel and you'd always make more power with a richer burn of course

and like you were saying targeting your 0.85 and 0.86 is

normally the way to go especially on the turbo charged application

because you've still got a bit of component control in there and you're still

when I say component control you're calling the piston crown. You've got enough

fuel to burn and to cool but when you're at the end of a

two-hour stint at Le Mans and you haven't wanted to carry

you know you don't want all that weight in the car, yeah effectively

you would start to run a leaner lambda target and

you'd probably hear on the F1 radio a lot of time the term lift and

coast used in F1 and obviously what that means is

they're effectively getting to the end of the straight and lifting a lot earlier

and getting onto the brakes a lot sooner but there's a little

period from when an F1 car lifts to getting on the brakes that

it's charging the energy recovery system as well which is another aspect

of the power unit so effectively you've brought more energy

out of the turbo and the K and you've got that on your next corner

exit so yeah there's just different scenarios and

generally on an LMP engine we'll probably have

around I don't know sort of 48 different cow selections

and strategies so you might generally have

four to five main fuel maps that you can select for a two-hour stint

and it just all depends you know another thing is

if you're at a point of the stint and you're racing

and affected and you've got the fuel on board you're obviously but the strategies

obviously through a 24-hour eraser are here

all over the place really so you just need the tools within the cow switches because

one thing that you can't do at Le Mans which we

actually have capability to do is map live you know like

obviously a lot of stuff can be done we have live telemetry coming back one way

and you could in theory map a car live on

circuit but there's regulations at Le Mans and NF1

that prohibit you from mapping the car live so

all of these strategies have to be built into the cow switch to navigate yourself through

the two-hour stint on the tyre and also the 24-hour erase.

Maybe that's a good thing 23 hours into a 24-hour erase I can imagine

the engineers would be running on a lot of caffeine, a lot of red bulls

and probably very little sleep so maybe the live mapping at that point might be

counterproductive when you press the wrong key accidentally.

In terms of managing all of those different calibrations though

obviously the driver is probably not trying to concentrate

on 24 different map strategies and which to choose and when

to choose them, he's probably wanting to just drive the damn car and race the cars

around them so does that come down to you or an engineer like yourself

at the track, looking at all of the data, looking at the fuel burn

looking at the relative speeds to the cars around

deciding when to change to a different strategy and what that strategy

would be? Yeah for sure there's a lot of coaching on switch position

so you would obviously have your switch positions for engine control

you'd have your switch positions for traction control and then especially with the

AER engines at Le Mans we had different settings for anti-lag

so we was running anti-lag at Le Mans and we'd have different variations

of that strategy some harsher than others so yeah

you try and build, you go into war effectively when you go and do Le Mans

and you're trying to build as many strategies and scenarios

into the cow switches to get yourself through and obviously a lot

of that knowledge and strategies get built in pre-season testing

and the races leading up to and after Le Mans so much time is

spent in them areas and developing so just getting

the first blank sheet engine off the dyno the work

then just starts really it's quite a lot of work up to that stage to get

a reliable engine and then you get to the circuit and all of

them strategies and mapping scenarios all that the work is

yeah it's a big task. No doubt. Alright I mean we could talk probably for

another hour about Le Mans and AER but let's move along

obviously pretty interesting to talk about your time with Mercedes

F1 and I'll just pre-empt this for our listeners

obviously most people could understand that anyone involved

in F1 there's not a lot that can be talked about openly

so we'll respect the fact that you're probably not going to be able to dive too deep into

any of these elements but for a start how do you even

get invited to go and work at Mercedes F1, how does that

come about, that opportunity? Obviously when over to Mercedes

was when the V6 turbo engine was being developed

and my experience at AER developing turbo

charged engines for Le Mans my CV sort of had what they wanted at the time

I would say so a random phone call in my dad's

kitchen I was literally just making some toast the phone rang

and you've been invited for an interview at

Mercedes HPP and yeah it was a bit of a surreal

feeling. I would assume that conventionally you're not

going to get a foot in the door at that level in a Formula 1 team, any Formula

1 team without an engineering background in

degrees, would that be typical? There's obviously quite

a varied there's varied jobs within the factory so you know you've got

your engine builders, you've got your wireman building looms

and generally the engine builders and wiremen wouldn't all have a degree

obviously it helps to get your foot in the door, some of them have just

got experience like myself you know I had the experience and I've been

there and got the t-shirt and that's what helped me to get in but the

conventional way to get there is yeah to do at least a bachelor's degree

for three years and then move on and a lot of

universities now especially in the UK have really great

motorsport degrees and obviously there's Formula students so a lot of

people migrate through the university, do fall in a student and

that is their intro. A lot of the F1 teams have

sort of got guys in universities to bring them guys on board so it's

quite a nice thing in the UK, there's quite a lot of opportunity which is great.

Yeah definitely I mean obviously the hub of professional motorsport at the

upper levels for sure. So what was your position at

Mercedes, what were you actually doing on the day to day? So I sort of went

like I had the ability to go through the factory so I was there for

two years, started off in an engine strip and diagnostics

which is basically taking engines that have been at the track

and taking them apart and sort of looking at reliability aspects of the engine

effectively and then the other stages of my career

there I was in what is known as energy recovery now obviously when I started

at Mercedes energy recovery was a very new

thing, we had CURS at that stage but energy recovery

was a whole other chapter in engineering so yeah I was

involved in energy recovery, the development of it and then I had

the opportunity to go track side with the energy recovery unit as well

and sort of help track side operations and the first test developments

and races of that setup. Can you maybe give us a quick

rundown on how the energy recovery works for those who maybe aren't F1 phonetics?

Yeah so effectively the front of an F1 engine is gear driven

you'll have a, it's kind of like a elaborate alternator

on the side which is called the K so when the car's breaking

the engine is putting energy into the K and the K is creating

electricity like an alternator and storing energy

in the battery pack which is underneath the driver's seat. Also the

same with what we call the H so you've got a motor

or an alternator on the outside of a turbo and that is

creating electricity and storing it into the battery pack. It's like

a free phase connector to the battery pack and once the battery

stored or when you want to deploy the energy from the battery pack

it actually comes back down them same lines that have charged

the battery pack and then turns its electrical energy into

power and the K puts power back into the drivetrain on the front

of the engine and then the power that comes up to the H helps to spin the turbo

so effectively you have no lag because you constantly

have a turbo that is up at your perfect operating speed.

Now from what I understand as well the MGUH that you're just talking about

the turbocharger element that's being removed from the 2026

regulations, is that right? But the MGUK is being retained

and that's actually being made more powerful for the 2026 regulations as I understand it.

Yeah I think there's actually a lot more engineering possibly that

goes into the H which would probably raise budgets for everybody

so maybe that's a cost cap but I've been out of F1 for a couple of years now so...

Sure, one sort of side of that that's always interested me

is looking at it back when I was younger watching F1 back in the

V12, V10 days, it seemed like back then technology

from motorsport did sort of trickle down into OE and that was

kind of like F1 or professional level motorsport was kind of the breeding ground for some of these

new strategies, technologies etc. These days I don't know if I could say

the same and sort of that MGUH at least to the best of my

knowledge hasn't actually made it to production level

cars except for that AMG1 which is a bit of a

niche case study anyway. Are you aware of that technology

being used anywhere in production cars? No I haven't really seen it anywhere

to be honest obviously it's not cheap technology so I would say

that's probably just the price restraints a lot of naturally

aspirated tech can effectively just go straight back in but

when you come to complex electrical systems it's not

just the battery pack and the MGUH is actually the control electronics

as well to control all of that by the time you add that whole package up I just

suppose it's something that's out of the price cup of a general road car.

In terms of the way the MGUH is used

by the driver, I mean just can you give us some insight into

how much of this is automated, I'm guessing here at least you sort of alluded to the fact

that under braking it's charging but we also see that the driver

can at least as I understand it purposely harvest energy, basically sacrifice

some of the power of the engine under full power acceleration

to actually purposely charge the battery so that they can deploy at a time

that's giving them a strategy advantage, can you talk us through a little bit of that?

Yeah I don't know how in depth I can go on it but

I would say a lot of the MGUH power is

normally deployed on corner exit so you have such a

precise power deployment that you can deploy

energy per corner exit and ultimately dictate your

tyre slip so it can be used in different ways, sometimes it

will be used at the top end of the rev range but a lot of the time

it will be used to save the rear tyre effectively and

you bring the power in from the MGUH on corner exit and then

phase the ice or the internal combustion engine in over the top

and bring the power in and obviously that deployment we're talking

80 milliseconds, it's a very short amount of time that the MGUH

has deployed there and in the engine phase is quite quick

but in data it obviously looks a lot bigger but when you're talking about

the tyre deck that we had and then restrictions on Paredes

your really power deployment becomes the part

that wins you races effectively and that's been

a core of my work with my wire mapping that I do at Bourne HPP

with life racing as understanding or seeing firsthand

how to deploy the power once you have all of this power

it's really about getting it down to the tyre and there's a lot of

sensors that we can put around a modern car nowadays to actually

work out our rear slip and actually to a

precise percentage know how much power we need to deploy

I think really it just comes down to just another area where

for those who are occasionally involved in maybe the odd track

day in their road car, particularly if they're still on a dot road tyre

you miss a lot of the nuance of what happens in

particularly endurance style racing where it's not about the driver

going 10 tenths and getting the quickest lap time that they can

like that would be great for maybe one or two laps but

particular over a long stint, a couple of hours or whatever it might be

you'd end up with the tyre degradation through the roof and you'll be fast

for a couple of laps, maybe five laps and then the tyres will just be completely

rinsed and your lap time's gone so it's about

managing the tyre degradation and managing the amount of energy that you're

putting into the tyre so that the tyre has still got some life left at the end of your

stint correct? Correct and also going back to where we started at the beginning

and fuel efficiency across an engine to actually try and make the car

efficient through 24 hours, any rear tyre slip that you see

is wasted fuel and engine energy so actually

what you're doing through a two hour stint with a power unit is effectively

you're turning the power down, you're constantly controlling and dressing

the power out, as the tyre dead goes up you're just

fettering out, ignition, however you want to do it, fuel to try and

sometimes going to a lean a burn strategy will actually give you

like we spoke about, you lose power, you might run a lean a burn to

save the tyre because effectively you might have knocked out 60 foot

pound of torque at corner exit free and that's what you've needed to save

the tyre so and actually also you're then saving fuel so

that's where the strategies that we build earlier in the projects

all come to your favour at the end of a stint generally.

I think we probably need to move on from your background, this is probably the longest

discussion around someone's background I've had on the podcast but your background is obviously

somewhat unique so I think that's justifiable and definitely has been some really

interesting insight that you've given us there but let's fill in

now from leaving Mercedes F1 to founding

Bourne HPP, how did that all look? Yeah so obviously

you're always looking at every sector and

I had a mega mega time at Mercedes HPP but I saw that life racing

were developing some cheaper ECUs and also

they had the GDI4 at that time which you can actually

utilise direct injection at a very decent

cost price, I think a GDI4 was around the £1800 mark

so all of a sudden all of this learning that I had done for

two years in F1 there was the tools available to go and take

this to all other levels of motorsport and you know when

you've done what I've done in my career I think the next natural step

was to create my own engine company and tuning company so

there's been some massive hurdles to get around but obviously

one of the big bits that made it easy to make that transition into having

my business was having them tools to go and do the job that I

had done my whole career and be able to offer it to the lower levels effectively

I'm going to come back to life racing in a bit more detail but before we do that

just give us the 30,000 foot view of what HPP or Bourne HPP

looks like today talking here, size, location, number of staff

So we're a four man team at the moment and our skill set

like we try and do everything with them four guys so we've got a bit of

design, we've got engine build which is obviously the fundamental way

that we make money at Bourne HPP is selling crate engines

as we touched on before we started our business around the Honda K20 engine

because it's just so widely used and such

a good engine when you go back to that blank sheet engine design

and you open up a K20 you're like yeah I've got the ingredients for the

recipe to start with here so it was obviously the engine and I've got a lot of

passion for it so it was the engine to start the business on but yeah effectively it's

creating very efficient, higher power, power units

and incorporating like a whole package to the customer so we're not

just an engine builder, we'll build engine harnesses

we'll supply ECUs, we've got an in-house bench dyno where we'll

build the calibrations and then we'll go out on circuit and track support

them so my real role is I suppose customer liaison

and I get involved quite heavily in the mapping and the track support side

I've got a couple of really good engine builders with us as well

so we sort of tick all the boxes with a small team

Alright well obviously I want to dive into the K20 and pick your brains for

as much as I can for my own selfish requirements

as I mentioned at the start but before we do that just bring it back to

life racing and this really was born out of advanced engine research so

coming back to that point at AER, why did AER

decide that the current offerings of EC on the market

weren't up to what they needed, I mean it must be a massive

operation to not only be designing these ground up

bespoke race engines but also then to design and develop

your own engine management system I think it sort of actually happened

the other way around for Mike Lancaster he's the founder so he

started a company called Pectel with Simon Phillips

and then they went their separate ways and Pectel ended up becoming Cosworth

Electronics and Mike Lancaster ended up taking

they both left the same DNA in the heads of what they'd created

Which is why if you look at Pectel or Cosworth versus

a life racing or Cyvex there's a very

obvious consistency between the brands or the products

correct? Yeah definitely, even how it's all laid

out on the screen and how you get through branches

I think all of that was done right at the beginning and then guys were sort of

the first brainchilds behind really a lot of aftermarket ECUs

after Pectel have sort of followed that same layout really

so I think that was the core really, that was the first seed there

and the actual engine side of AER come after Mike supplied

ECUs to Nissan and they ended up winning

British Touring Car Championship with Mike's Pectel ECU

and in that Nissan relationship grew the first big

contract that advanced engine research got was the Nissan World Series

which is, it was sort of two down from F1 and was a feeder

I think Sebastian Vettel won it one year so you know it was a big championship

and a big engine project to be involved with and we developed the Nissan

350Z engine into a sort of 480 horsepower

race engine but we had, it was a one make championship so

it was all of our engine, that was the first life ECUs

would run that championship so yeah I think we didn't ever get to the point

where there wasn't something on the aftermarket for us at that stage

it was just the founder had already come from the ECU into the engine

Now obviously that makes sense, I'm sorry I'm losing track of my ECU

history there because as you mentioned that I did realise that life

was born out of Pectel so thanks for clearing that up

What is it in your experience, obviously you've been using life racing products for

a fair while now, what is it in your opinion that separates them

from other ECUs that are out there on the market at similar

price points and capability points? There's not a massive separation

I think the way that life racing has controlled Lambda and some

of the more detailed strategies that we would have developed at Le Mans

are closed loop, not controlling life racing, there's so many elements

that are really really good in the ECU and probably better than others

but there might be other ECUs out there that do certain aspects

of the cow better, I don't really know, I think for me it's my

tool effectively, like from the age of 16 I've grown up

on Dinos at AER mapping with life racing and spent

a lot of time with Mark Colby that developed the software so you know

he was the original coder for Pectel and then moved to life racing

so it's just my tool, it's my, if I'm going to go to war

it's just my weapon of choice effectively

I think that sort of mirrors what I've said on the podcast a number of times

if we look at two capable ECUs and

you are just looking at power and torque capability, I mean essentially

within reason you give the engine the same amount of fuel and the same

ignition timing, it's going to produce the same power, so we're at a point

now where any high end ECU is going to be able to do

a good job of the fundamentals, physically running the engine

but it's the subtleties around some of the strategies

which I think are where those differences creep in and again I've said

time and time again, you can have five ECUs that all have traction control

and I put traction control here in air quotes because

there's levels to this and traction control that's going to be

effective in when you race is at Le Mans is very different to

a traction control on a lower end product which yes it'll stop the wheels from spinning

but also you're going to lose 3-4 tenths of a second

through that particular corner exit as a result of this overbearing

traction control and you know multiply that by closed loop knock control

as you mentioned, lambda control and every other element that these modern

ECUs use. The other side of this which is really

easy to overlook is I know a lot of people are kind of bringing this back to my

experience through my old shop, they turn up looking for an ECU for their project car

and maybe they've sort of trod some forums and they've seen success

with XYZ brand and maybe that's a brand that I as a tuner

have never seen before and that's their adamant, that's the one they want.

Well yeah again we come back to the fact that if it's a capable ECU

it'll make the power in the talk, that's no problem but me as a tuner

I know a different brand intimately like you do with

life racing so if the customer actually takes your advice

and goes with a product that you know inside and out, you're going to be able to get

a better result in less time, you're going to be able to support that product better

and result is happier customer, car that makes great power in

talk, great drivability, everyone's happy with the result and probably

ultimately they're going to spend less money with you. Does that

sort of match your experience or the reality? Exactly that,

I mean it all comes back to efficiency at every level and obviously the

customer's pocket and trying to be as efficient as you can with their spending

is one of the main principles that we've adopted at Bourne HPP

it's very difficult so you know having life racing as my tool

we've built a lot of base maps with different engines and in the end

you can get the base map so good that you know it is just tweaking

per new engine and obviously a lot of what we've done as well is building

engine specs so you know we're delivering the same engine

package time and time again to multiple tutor customers and

actually saves money over 10 customers you're supplying that one developed

engine and map for a particular chassis and that's what we've

tried to achieve is to try and give the best product for the

least amount of capital when times are tough out there in the world

to try and keep everyone racing and still having the equipment to be at the front is

obviously the technical challenge that we're facing now. Yeah, definitely.

Now we have had Ryan from Cyvex on the podcast

in previously so we might link to that show if people want to

go a bit deeper but just with the sort of differences or

comparisons I guess between Cyvex which is born out of life racing as well

can you give us a quick overview of what life racing and Cyvex

are, how they relate to each other and the differences? Yeah, I mean

they're fundamentally exactly the same code. The reason that Cyvex

was born was because when I was at Advanced Engine Research

we just didn't have demand power or the need to

go to the aftermarket. Everything we was doing with life racing

at the time was all developed like sort of built around our Le Mans project

and that was AER's core business was

American Le Mans series and so we didn't want to go down that aftermarket

route and deal there so Cyvex was born. I think it was

Charlie that come over and saw the capability of the life racing ECU

and then Cyvex was there and I've had the pleasure of

working with Ryan, he's a very knowledgeable guy and what they've done in that

world is just mega and it's also given me, it was one of the other

parts of setting up Born HPP is that they already had all

of these, we are a Cyvex dealer now as well but they already had all these

great plug and play management systems that when we're out just

doing the job you can just buy off a shelf, plug in

and off you go and it is my tool, it's how my mind

works and engine management is from a young age has been how

life racing set out, it's just ingrained in me now so it was such a mega

thing. So essentially focus of life racing is on

the professional level motorsport, no real sort of direct

support for the enthusiast level aftermarket and

they've left Cyvex to basically fill in that void in the enthusiast

market. Yeah and I think in the early stages of life racing

the professional world of motorsport was its biggest customer

but I actually think Cyvex are doing much bigger

numbers now, they've managed to take the brand globally and it's well

respected across the globe now and I think there's more ECUs getting sold

through there. And I guess it makes sense you just look at the numbers that

there is always going to be a limited number of teams operating

at that highest echelon of professional motorsport but there's hundreds

of thousands, if not millions of enthusiasts out there who need ECUs

to make their cars run. And I guess getting a little off topic but

the focus there also needs to be considered if life racing had sort of

dived after that enthusiast market as well, yeah they'd be selling a whole

lot more ECUs but the tech support nightmare that

that would bring could also be very difficult to manage so Cyvex

have kind of taken on that role. I just wanted to interrupt our interview

with Terry here and talk about a package of courses that we've put together.

It's got to be perfect for anyone who's enjoying our interview so far.

That is our engine building starter package. This package of courses

is normally $299 US, using the coupon code

$299 US. This package of courses starts with our engine building

fundamentals course which will teach you the fundamentals of how

the four stroke engine works, all of the components inside. You'll learn about

the machining operations that we typically need when we're building a performance

engine which is really important because it will help you to speak

the same language as your engine machinist. You'll also learn about the specialist

tools and measuring equipment that you're going to need to build engines.

Moving on from this, we're including our practical engine building course and this

builds on the knowledge taught in our fundamentals course. This time you'll learn

the practical skills that you're going to need to understand when you're building

your own engine. We've also broken the engine building

process down into the HPA 10 step process and this

makes it really quick and easy to build your engines. Each of those

individual steps is relatively quick and simple to complete and in no time

you've got to the end of those 10 steps, you've got a completely built engine

and you're going to have the confidence that when it comes time to start it for the first time,

it's going to produce great power, great torque and most importantly

it's going to deliver great reliability. The course is generic so it doesn't

matter whether you're building an inline four cylinder or a V12,

maybe it's naturally aspirated, turbocharged, supercharged, the

10 step process still 100% applicable. Within this course we also

include a library of worked examples where you can watch the HPA 10 step process

being applied on a real life engine building job. In that library

we vary the type of engine we're working on so that you're going to get experience

on a wide range of different platforms. And relevant to today's interview

we will be adding a worked example very shortly on our

own Honda K20 naturally aspirated endurance car build.

Moving on, we're also including in this package our

how to degree a camshaft course and upgrading the cam or camshaft

is probably one of the most common ways of getting more power with a performance

engine build but degreeing or dialing in that cam correctly

to the manufacturer's specifications is critical if you want to get the performance

that the cam has to offer as well as making sure you avoid expensive

failures such as valve to piston or valve to valve contact.

This course also includes a simple six step process you can apply

regardless whether you're degreeing a cam on a simple pushrod engine

or maybe quad cams on a V12, it doesn't matter.

The six step process is 100% applicable.

We're also including two full years of gold membership which gives you access

to our private members only forum, this is the best place to get reliable answers

to your specific engine building questions. And that gold membership

also gives you access to our regular weekly members webinars.

These webinars are a live lesson that we hold every week, we vary the

topics between engine building, engine tuning, wiring, 3D modelling

and CAD just to name a few. If you can watch live you can ask questions

or get answers in real time but if the time zones don't work for you, as a

gold member you can review our webinars in our archive where we've got around

350 hours of content, this is an absolute goldmine,

one of the quickest ways to expand your knowledge on a huge range of performance

automotive topics. So remember that package is normally $299 USD,

use that coupon code borne, HPP100,

get $100 off, you are still protected

with our 60 day, no questions asked, money back guarantee.

So if you purchase and for any reason at all decide it's not quite what you expected,

let us know, you'll get a full refund of the purchase price. Let's get back to our

interview with Terry now. Alright let's move on and get into this Honda K20,

I mean yeah no secret, it is what I'd consider

arguably, well maybe unarguably the best 2 litre

4 cylinder naturally aspirated engine out there.

I don't know if anyone could come up with something better but if it's not at the top

it's very very close too. What is it about the K20 that makes

it so good? Because I mean in this day and age it's actually a reasonably

dated engine, at least the earlier port injected K20,

it's an older design now. Yeah no I mean

it's just fundamentally good in every area, I mean one of the big reliability

aspects I suppose is having a chain drive over a convention

or a lot of 4-2 litre engines over a cam belt. I think there's a lot of

especially when you're taking the engine and putting it on the paddle shift, the rate

of acceleration of rev change is so high, it's not really

something that you always want to be running a cam belt with but to have a chain

is effectively the perfect setup is to go

gear drive but from a cam belt to gear drive there's chain drive in the

middle and I think when I've been using the engine in V-to-V

and endurance racing that chain drive has been one of the big aspects

for reliability. But yeah also rate of acceleration of revs of the

engine, just XXL out the box is crazy

anyone that's ever driven one will know. Obviously they've got

the mathematics right with the B-series engine and that had great XXL

of revs but I think it's not just the power that the engine makes

the way that it has been designed on airflow and engine design

to create that XXL is mega and it's something that

you only really normally see in top level design from blank sheet

engines to have that rate of acceleration of revs and I think

this is something that a lot of people miss is a lot of people are just

chasing power numbers but actually engine speed and rate

of XXL is also something that gives you a lot of on track performance

which is why when we've gone to design our own

turbocharged version of the K20 we've gone to a 2.2

instead of a 2.4 because a 2.4 would offer you

more power and torque but actually your piston speed

declines massively when you go to a 2.4 so what we've

found is with the 2.2 we've gained power and torque

but we haven't lost the piston and crank speed which is actually mega

on corner exit and obviously when you're running

an aero car like we are with Suki our time attack car

trying to get to maximum downforce speed generally

with that car it's about 150 mile an hour

we want to get to 150 mile an hour as fast as we

can then we hit the rear wing of maximum downforce and

you really need like a lot more you know 250

horsepower more to punch through the maximum downforce so having

that rate of acceleration of revs in what a lot of people call the

line under the curve to try and have that from corner exit to your

maximum downforce point and get the car accelerated as fast as you can

is really the key to on track performance and obviously the

Honda bodes itself well for that so.

Just coming back to the sort of rate of acceleration

of the engine, I mean this is again an area that most people would give

no consideration to and in simple terms I would say a good example

of what you're talking about here is maybe if you manage to

remove weight from your flywheel which is pretty easy to do if you're starting

with a production engine, you're not going to measure the improvement

in engine performance from that lightweight flywheel on a dyno, it's

still going to produce the same power and torque but it's sort of almost no

different to removing mass from any other part of the car, it's actually going to

allow the car to accelerate out on the track quicker so again what you're saying

they're getting up to that Vmax 150 mile an hour where you're basically hitting

an aerodynamic wall quicker, is that a good analogy there?

No perfect, a lot of engine design and tuning nowadays

people forget about the weight and I think that was probably something that they

focus more on in the older days when they didn't have accurate dinos like we do

now, a lot more emphasis was put into lightweight cranks and

lightweight components and what we see in some of the aftermarket now

is there's quite a lot of, we strip engines, there's quite a lot of bulky bits

and heavy bits and obviously when we went to design

all of our own internals for our 2.2 turbo

a lot of emphasis was put on the lightness and strength

trying to retain the strength in the design but trying to keep all the components

as light as we can and trying to gain as many winds as we can

on engine XL. Alright I want to just come back to another

element you talked about there which is the chain drive, it's pretty common

on production engines these days obviously in terms of a factory

engine low to no maintenance compared to a cam belt which is

great for the end user. I'm just interested though you mentioned about gear drive

which is as I understand it, a reasonably common approach on

all out competition engines. Where's the downside with gear drive, why is it

not being used in a production engine? It's just very expensive

and also like most of the race engines

at that level that I've worked on only ever 6000km life

which is the distance of Le Mans built into the regulations

of F1, an engine life is 6000km so

they do take a lot of service and there's bearings inside the gears

and there's a lot of lubrication, it's just a whole

a much bigger technical move to get to a gear

driven engine and a lot more service and required effective, it's not really

something that you would ever see in a road car. Okay sure enough

the advantage of that is this just in absolute accuracy

of cam phasing with crankshaft position? Yeah I mean

obviously there's other benefits that you can incorporate

okay and easily but when you've got that amount of power going through

the drivetrain, gears are generally the most robust and reliable

way to do it and like we touched on, like a lot of high level

engines have such high speed of Excel that sometimes

a chain, well a chain generally isn't going to be or stand up

to the pressure that it's going to see so yeah that change in speed

especially when you're going, you know you're breaking into a corner, you're

buzzing down the gearbox and the sequential gearbox, the rate of acceleration

of change there, you really need a heavy gear set in the gear train

on the engine for reliability effectively. Okay alright so

we've talked about the fact that the K20 is a great engine

off the showroom floor, where are its weaknesses, where are the

problem areas that kind of need to be developed out of it when you're turning

it into a race engine? So one of the big aspects is

obviously oil delivery to all of the components and one of the first

things that we do is go to a dry sump set up, the bearing

clearances that you end up running the K20 are very crucial and

they literally don't like running without any oil pressure. As soon as they're

anywhere below sort of three and a half bar we've seen issues

so as soon as you're incorporating G, a lot of G into a car especially

with our time attack car, we're on slicks with twice the

amount of downforce as an F1 car has, so the G's that we're seeing

are very high and the amount of oil swashing the wet

sump is just far too much for the pickup pipe and we've had to go

to a dry sump set up so that's one of the key things for reliability

I think is getting your oil system right and also getting

into oils too. I can understand it, the sort of time attack

high downforce level, the dry sump obviously it sort of becomes

non-negotiable and while they are expensive, if it saves you an engine

all of a sudden it looks like a pretty cheap investment. However I mean if we take

it back a notch and maybe it's just a little outside of the realm of the level you are

working at, there are a number of solutions for

welding or bolting baffle boxes and sort of

trays etc that go into the factory sump and I mean I've had

personal experience with these at club level and they do seem effective,

is there a point where these are an okay solution

and if so, at what point do you consider the dry sump as the only way to go?

Yeah effectively we've had quite a lot of experience and there are some

good baffles out on the market and for a lot of tin top racing

that will be absolutely perfect, I think Skunk 2 do a baffle, there's a few

different companies that have produced the baffles and they work really well

at just keeping the oil around that pickup pipe and not

letting it move to all sides of the sump. I think the big thing on a K20

is when you're entering a corner with heavy braking

quite a lot of oil can disappear up the front timing chest

because there's the gap there so I think having a decent baffle

but there's some other bits and pieces we've made some little plates up on

some engine specs that we've done to just stop the engine from disappearing

up that front timing chest, I think that's another key feature really so

In terms of the lubrication benefits

that's pretty understandable with the dry sump system, I'm interested to sort of

get an insight into do you see a power

gain with a properly designed dry sump system and again

this is easy to overlook but one of the benefits is that we're removing

those blow by gases, the evacuating the crank case of

blow by gases which includes oil droplets as well

so this reduces therefore the windage losses in the crank case which is

basically the conrods and the crankshaft counterweights having to sort of break through

this oil mist. So there can be some benefits there

also the fact that you can run a vacuum in the crank case if it's

sealed, can improve ring seals. So yeah can you give us some understanding

of how you see that working? Yeah so we haven't really seen benefits

on the K20 yet but like a lot of the blank sheet engines that I've worked on

we have very efficient scavenge pump system so as soon as

you said you can get the crank case pressure into a negative

you do start to see big horsepower gains but I'd say

the general kits that are out on the market for the Honda K20 is very

difficult to get the crank case pressure below atmosphere really

so really it's more of a reliability thing from what we've found

so far and we haven't seen pumps on the general market that are

that efficient that can start to pull a negative crank case and relieve pressure

from the bottom of the piston so yeah we've just gone

with a lot of stuff that we've done to a dry sump system, one for packaging

it obviously helps to standard Honda sump is quite deep

so we've done a lot of installations on, we're working with a company

at the moment called MK Cars that produce a sort of 7s

lookalike car, a kick car that you can buy and assemble in your garage

but for that application trying to limit the sump

to get the ride height back on the car has been a big movement really

but yeah I think there's not too much power gain from what we've seen

it's just a reliability and a packaging point of view with a dry sump set up.

Well I must admit that's not what I wanted you to say, we've got a daily engineer

and dry sump system going on our new K20 and I was hoping

that we might see some benefit from it, it may

still pan out that we actually get to do a back to back between wet sump and dry sump

which obviously will put that argument to rest at least for that particular engine

and as you mentioned for those who maybe haven't sort of had intimate

knowledge of the K20, it is actually quite a tall engine so that can

provide some packaging issues, case and point is we have one

in an EF chassis CRX and it's a big engine for a little

chassis so the other benefit of going to the dry sump is it's going to reduce

the overall height of the engine for us making packaging a little bit easier.

Coming to the piston design, there's always a bit of a

balancing act when it comes to choosing a compression ratio

and the octane of the fuel available is obviously one of the driving factors there.

What have you sort of settled on as a compression ratio

target for naturally aspirated applications?

A lot of our crate Honda K20 engines are obviously designed to do

two seasons of running on UK pump fuel so what we've

found is that we can't go anywhere above 12.5 to 1 compression ratio

so just pre-ignition and detonation creep in

when you start to raise the compression ratio above that so using

that as a limiting factor to produce more power out of

a two litre engine we've really dialed in on the bit that we can change

which is obviously cam profile when we've spent a lot of time developing

cams for the Honda K20 we sell a high lift cam

on our website and one of the aspects of going to that high lift

cam is to get rid of the VTEC also so we're sort of

limited a lot of clubman level motorsport in the UK and

Europe we're limited to 99 ron octane out of the pump

and really your compression ratio is dictated by which fuel

you can run on so. Yeah absolutely I'm just interested

on a tangent there if you were not limited on octane

and maybe you had the benefit of like a proper race fuel or

alcohol based fuel where would you then go to

with compression ratio and do you kind of get into

this area of diminishing returns obviously as we build up

the dome on the piston to increase the compression ratio

we sort of start interrupting or potentially interrupting the flame front propagation

during combustion as well so at least again as I understand it we can sort of get into

this area where we add compression ratio which should be a benefit but we're

actually compromising the combustion event and therefore kind of

going round in circles and making no gains. Yeah and I think the other big thing is

not to focus on the compression ratio but to come back to the overview again

and focus on the airflow if you keep building your

like so with a naturally aspirated piston I would call that piston shape a penthouse

so we have that sort of domed penthouse shape

and a lot of the design of that in the early stages was to

increase the air speed across the top of the piston so that shape

sort of pushes the air to the top of the combustion chamber

in the head and as you force the air into a smaller gap you increase the air

speed so this comes back to having the sensors

either end of the engine like you might just see some

small gains by keep increasing the compression ratio but then you

might start to lose air speed across the top of the piston so

I think this is where when you don't have all of this sensor set up around

an engine you could get a little bit lost effectively and you're

chasing or maybe going down the wrong avenue and I think the big

thing in engineering that I've learned over the years is not to ever get lost

down an avenue keep coming back to the overview and looking at the broad

spectrum of what you're trying to achieve and where you're at with other aspects

and chasing compression ratio in my experience

is not really the way to always make the power and build a

efficient engine so. So summing up if you were

not octane limited am I getting the sense that you wouldn't really

be putting a lot if any more compression into these engines

I think if I wasn't octane limited would probably end up at around

13.5 or 13.8 to 1 from other engines that I've run

NA engines that I've run on nice fuels that's sort of where we've

ended up but obviously the real trick to all of this is your compression

ratio is one aspect actual piston shape to increase the

the air speed is the aspect that a lot of people don't really

focus on and that air speed is the bit that gains

the power. Fair, again we've kind of already mentioned this but

you can't look at one element in isolation it's the entire

package that counts. Alright coming back to

you were talking before about cam development and particularly developing

this high lift cam that eliminates the v-tech I mean I'm guessing that

there's probably no one listening to this podcast that doesn't understand v-tech but just to

be super clear Honda kind of at least I think pioneered this

and have two different lobes on the camshaft

a smaller lobe that's used at idle and low RPM which is

uses little lift and limited overlap for

good efficiency, nice road manners, good economy

and then at higher RPM they switch to a larger lobe with more lift and more

duration, more overlap that benefits high RPM performance. So on face

value I would think that's kind of the best of both worlds.

Compared to a conventional race engine where with one fixed cam profile

we're going to make some compromises at some point in the rev range so we've got gains in

others. Why go away from that v-tech mechanism on that

basis? Obviously a lot of the engines that we've gone away from that on are

full blown race cars and we're in control of gear ratio

so this is the other aspect you can never just get stuck as an engine matter

you've got to look at the whole drivetrain package. When you're in control

of gear ratios effectively you are going to lose power and talk

at the low end go into a fixed gear and cam but once you're in control of

ratios the engine never sits there, you're never operating in that part

where you've had a loss, you're only ever operating in the window that you've

had a gain and what we've found by so we have

a pin that locks the v-tech out, we've gone to a fixed gear

in our high lift cam and that has jumped power and talk

up massively from 4,500 rpm onwards

generally on track on a lot of race cars where the gear ratios

are changed per track set up, we would never see anything less than

5,500 rpm on circuit. So essentially you're never in a position

where you would have benefited from that low lift cam profile anyway.

Yep and then coming back to the efficiency that we've built into the Honda

all of the bits that I've learnt from my career and vibration

where we're not making the power and talk and we're never in that, we've designed

crankshafts and camshafts that all of their critical speed is

around the 3,500 rpm mark and literally the only time

our race engines see that is when they're leaving the pit lane or pulling away

from the box so everything is designed to be

between 5,500 and 9,500.

Yep that makes a lot of sense, I'm guessing there's a

potential reliability gain as well in removing or eliminating

that VTEC mechanism, just one less thing to mechanically fail got wrong?

Yeah there is but I suppose coming back from the race

engine world we've also developed parts for the fast road car

world and we've developed an engine package for the

MK which I touched on earlier which is like a 7s base car

and for that package really you want that full spectrum

you want that low low drivability, you want the power when you need it

and actually the VTEC system has been mega in that car package

the car only weighs 600 kilos so you know we don't need the

last temp for false power it's just not needed but to create a

very nice drivable package the VTEC we've retained and we've

developed our own dropping to keep the VTEC system and that's performed

well we sort of we're seeing over 250 horsepower now

on the dropping of the right manifold and an exhaust system

and in a lot of applications you don't need it much more than 250

horsepower that combined with the rate of acceleration of revs that you see in a

Honda even as a track car they still outperform quite a lot

of other track cars that your general use like there's a lot of

full stuff running about in the UK a lot of people into

pin nose and bits and pieces like that and there's just a whole different

weld what you can do of a K20 compared to what used to be able to do of a 2 litre

pin nose. Yeah I mean absolutely I remember when I was

just getting involved in the industry back many more years

ago than I care to mention and you know the magic number

always used to be for naturally aspirated engines that were

fairly heavily developed, sort of 100 horsepower per litre, that was good.

I mean if you were north of that you were doing pretty well and now we've got

a production engine that essentially with a tune I sort of just

looked at some of my numbers and with a stock K20 with

air filter headers and an exhaust system and a reflash

tune using maybe Honda, 220 odd horsepower

at the wheels is pretty easily achievable so it's amazing

how far technology has come, go back to the old Ford Pinto engine, you're going

to be struggling to sort of trump a well-developed K20

aren't you? Yeah no and I think the other bit that Honda got so right is

they understood the air flow when they come to design this production engine

it's very difficult with an NA with the right compression ratio

to the fuel to mis-tune and to run into detonation

where they've got the air flow or so right the engine characteristic

is that it just rolls over so actually for a lot of people that

have taken your courses and are getting into tuning I would always

urge them to go and map a Honda because it's the

air flow so good you can get away with being even

3-4 degrees you'll just literally see the power drop but you won't break the engine

and I think coming back to this Clubman level what it needed was

this very reliable high output power engine and that

Honda K20 ticks all of them boxes you know it's very

difficult in my experience to break it and that is obviously

the core aspect of what makes a good Clubman level engine.

I mean challenge accepted by many tuners out there.

Any engine can be broken if you try hard enough but I would agree they are a

fairly easy to tune engine albeit in stock form there's a few things

going on with the cam control and the VTEC mechanism but

you can be a little out of the window and they're not going to immediately

sort of bite you it's a good engine to learn on

particularly because it does have those more advanced elements. Now I've already talked about the fact

in your race engines you're deleting the VTEC you also alluded to the fact

you're using fixed cam timing instead of the IVTEC or cam control

in stock form that gives you 50 degrees of cam movement

and again at a real quick high level overview

we could advance and retard the cam timing manually using Vernier cam gears

but that's fixed once we've selected a cam timing

we can't change that on the fly and there's normally some compromise that comes into that

whether you want to focus on improving lower RPM performance or higher RPM

performance with continuously variable cam control we can

advance and retard the cam timing as the engine's actually operating kind of getting the best

of both worlds. Now obviously as we go larger in the cam profile

and there's physically just less room to swing that

cam you're going to run into problems with contact, is that

why you've eliminated the cam control

mechanism or again as it comes back to that you're just operating it over

a relatively narrow RPM range so the benefit in low RPM performance

is kind of really irrelevant at that stage. Yeah exactly that

and once you go to that fixed gear I think coming back to the overview

and not going into one component, coming back to the air flow

we're just trying to in that small rev range from 5.5 to 9.5

thousand we're trying to create not just the

best air flow through the engine but we're also trying to create

scavenging from the exhaust system so you get to a point

with a straight 4 engine that you get what's called a secondary pulse

and if you've not understood the whole overview of the air flow

you can actually end up with a lot of back pressure back on the exhaust valve

killing power and obviously the perfect place to get to

so we end up stepping exhaust so we would have two or three steps

in the exhaust system getting the inlet track length right

and in the cam profile you need to get all of them aspects right

and once that's all perfect you can actually get into what we call

scavenging where you've lost the secondary pulse

and the engine is actually scavenging out and you've got the pressure

going one way through the exhaust system as soon as you can get to this point

with a K20 the power benefit is massive.

So that secondary pulse you're talking about there, if you've got that occurring

I'd be right in saying you're essentially diluting the fresh intake charge

during the overlap period because it's drawing exhaust gas

back into the cylinder basically offsetting some of the volume that's available

for fresh air and fuel to be ingested. Yeah exactly that

and like a lot of this fine level tuning work

will also be done track to track you know if we're going to Brandt Hatch

for instance we would have a whole different engine configuration

on an NA to what we would have at say Silverstone or a much longer track

and that's a lot of the work that when I first got into F1

we were still running the naturally aspirated V8

and there was a lot of work done before every Grand Prix on developing

the package for that track and the conditions it was going to see

so obviously when we're dealing with the aftermarket and the clubman

there's not so much room to be changing inlet

track length and exhaust length for the time but one thing with our

partners at AT Power they've developed an individual throttle body

set up for the K20 and it's got an interchangeable centre section

so you can actually change your inlet track length

and if you want to get to that and I'm sure as we

go through you know the next 20 years I think we're going to carry on racing

K20s and generally what happens in history of engines

is more money gets spent every year you go racing and the

development becomes higher and higher so bringing that experience

that I had from the NA days of F1 when I first started back into the

Honda and having that ability to change the inlet track length

and the exhaust length and sort of produce a set up for the circuit

that we're going to is really obviously we've sort of found a sweet

spot now we've sort of got a out the box set up which will generally work

at a lot of circuits you would just change your gear ratios to

that circuit but if you want to get into the last temps of it

there is always gains to be had from changing from a sort of a

low speed circuit to a high speed circuit and the engine configuration changes

Yeah that makes sense, there's no one size fits all

solution here if you want the ultimate performance. Since you've just touched

on inlet designs, let's just talk about the individual

throttle body style inlet versus a conventional factory

style plenum inlet. Where are the pros and cons of each?

I think most people kind of just assume that bolting on a set of ITBs

is instant power, is that always the case?

No I think a lot of it comes down to packaging. There is

with the K20 a small advantage from going to a

individual throttle body but the big advantage that I've found from going to an

individual throttle body is being able to run stage injection. We've built a couple

of engines now where we've had two injectors per cylinder

and coming back to that engine efficiency that we were talking about

your atomization of your fuel is much better at high RPM

when you can inject the fuel a lot later or a lot further

down the inlet track, it just mixes with the air and you get a much

better burn. So the high end engines that we've done, we've found

a small gain going to an individual throttle body but then we've made

that gain amplified by a running split injection and generally

we would run the primary injector up to about 3,500

and in the life racing so we was getting back to

management and every management will pretty much get

you MBT or peak power but then these little strategies

within the life racing allow you to phase the two

injectors one over the other. So when the engines flat out at

like 9,500 we've actually found a 70-30 split

so we've got the outer injector running 70% duty

and the inner injector running 30% duty, that's when we've picked up

more power but there's still more work to be done for us there

we've only really produced 3 engines to that level so far.

I'm interested and this is again from a purely selfish standpoint because

we're doing exactly the same aiming to run a set of secondary

injectors outside of the inlet trumpet so not to put too fine a point on it

how much more power can I expect from doing so and then

optimizing the staging, as you mentioned there you found 70-30 worked well

are we talking 1 or 2 horsepower, are we talking 5 or 6 horsepower?

So on a 2 litre race engine I think we've found

around 16 horsepower from getting the inlet track

and the stage injection and obviously the big bit is I've seen

a lot of people put individual throttle bodies on engines and then

they'll go and put the engine into an EP3 and then they end up with a

tiny little air box so a lot of it comes down to packaging

and alright it's alright having the stage injection but

you need to be able to get an air box scoop into that

to actually see the benefits from it and if you go back to

British touring cars we'll now run in DC-5s so to get our

air box shape we looked at some of the work that Neil Brown had done in British

touring car in the Super 2000s back in the day and

we sort of created an air box for the DC-5 application

that takes the air from on top of the rad

we've put some heat proofing underneath so you're not getting that heat from the rad into the air box

and then just having a nice package and not trying to restrict

the front of the throttle body is obviously key, I always call it the

bank of air but effectively I feel the bigger

air box that you can get generally is the best and trying to

get an air box to incorporate a panel filter is the most efficient

way air flows through from what we've found air flows through a panel filter

much more efficiently than a cone filter

and yeah you've got a much bigger surface area so

trying to get a big air box with a big surface area to incorporate a panel filter

is the key to unlocking the individual throttle body in a Honda and that's when

you start to see the gains. Yeah that makes a lot of sense and I mean again

it's kind of looking at the whole installation now we're sort of looking

even broader than just the engine, there's no point having

this ultimate inlet set up with the right length trumpets

ITPs et cetera and then having those ITPs jammed up hard

against the back of a radiator pulling in hot air, obviously that

just doesn't make sense on any level. When it comes to choosing

individual throttle bodies, not necessary just for a K series engine

this can be confusing and again we've just kind of gone through this process ourselves

there's a variety of different diameter throttle bodies

available, is this a case of just literally bigger is better

or how do you size this, is there some math

that you can do to find out what's going to be suitable

or is it unfortunately an expensive case of trial and error

testing back to back on a dyno and literally just seeing how the engine responds.

What we've found since developing the Honda is a lot of people have got caught

up in bigger is better and coming back to the overview of air flow

and air speed, when you're developing a higher power 2 litre NA engine

you want the air speed through the engine and air

flow to be as efficient as you possibly can and actually going to

a bigger port sometimes loses you velocity and air speed

so it looks like to the visual eye of

having a big port and a big throttle body is going to gain me more power

but actually you end up losing your speed and your velocity

and your power will go down so yeah, there is a little sweet spot

and I wasn't allowed to say a lot of bits about my earlier career but that's one little sweet spot

that I'll keep to myself for the moment just for our engines

but there is a sweet spot on throttle body sizing and head porting

so one massive gain that we've found for air flow across the K20 head

is to go to a one meal oversized valve on inlet and exhaust

and if you haven't got massive budget you can actually

go to a decent machine shop and have the standard seat cut

one meal oversized so generally when you rebuild an engine going to have the

seat cut anyway so we've done a range of valves that we now sell on

the Bourne HPP website as well and we've done a one meal oversized

inlet and exhaust that you can buy straight off the site but there is

massive gains that the big gain really is if you're going to run an

NNA application I would say on an overview don't go too big on

port size bigger isn't better but actually trying to

have a one meal oversized valve we have picked up the gain

so yeah there is a gain there. Again could you maybe

put some numbers around what that one mil valve size increase

is worth? So on our sort of Clubman level

two litre engine at sort of 12.5 to one compression ratio

one meal oversized valve individual throttle bodies

we've seen over 300 horsepower on pump fuel I think there's around

like an eight horsepower gain from going to the one meal oversized valve.

Yeah it's not insignificant. It's always that last 10 horsepower

we were stuck at around 290 or 99 run

for ages and then the big bit that opened up that last

10 horsepower to get past the 300 horsepower stage is all

down to exhaust track length and scavenging and once we crack the scavenging

of that air flow across that's when we started to

see that last bit of gain but unfortunately that last 10 horsepower

is always the most expensive. I think if you were to take a

crate engine or if you took an FD2 so if you took

the Japanese spec FD2 spec engine

or they call it the JDM spec that's got 12.5 to one compression

ratio from stock if you were to just put a high lift cam

fixed gears and one meal oversized valves you could expect to see

sort of 280, 285 on 98 run so

that's really the engine package that we've sort of pushed because

it's the most power for buck effectively.

People listening who are maybe more familiar with turbocharged engines will be thinking

about the numbers that we're talking about here maybe shaking their heads and thinking

what are we even talking about. I think that is why

naturally aspirated engine development is so satisfying when you get it right.

Maybe frustrating when you're not quite in the ballpark is because

you are talking about a lot of work for relatively

small gains in power. We don't have the benefit with a naturally aspirated engine

of just turning the boost up another 1 psi and making 20 or 30 more

horsepower, it's just not that easy but again comes back to just

making sure that every single component in the engine is working

in harmony with the others. Just following on from the

valve size discussion, the port shape or the

head flow for the K20 I think is probably one of the

elements that makes it such a successful engine. I mean it's just so good in stock

form. Is it an area where there's some good low hanging

fruit, getting a quality port profile put onto that cylinder head

or is it also really easy to actually make it worse?

The biggest gain that we've seen on an NA spec and also a track

spec engine is really opening the fruits up.

The area of the cylinder head just in front of the valve, you can

find some big gains with porting that.

Because we're trying to keep the air speed up on the NA setup, we haven't really

found massive gains with opening the stock.

We haven't really unlocked port up too much. We've obviously developed the

throat shape and then blended the port out from the throat shape.

And obviously going to that one mil valve, you're effectively

taking around a mil out of that area around the valve to unlock

the potential and surface of that valve. But yeah, so what the work

that we've done so far, we haven't even

got to the CNC porting stage to be fair. Everything that we've done at

our big power engines has all been hand-ported because we're not taking

too much out. Because what we've found is that the stock port

size is just so good and we've found other benefits

in getting, as we touched on inlet track length, cam profile

and exhaust length as a package to work. And then the big

bit has been the scavenging of the engine. I think a lot

of people have maybe got a little bit lost down the rabbit hole of the

port inside to produce power from these engines but we've found

it in other areas and it's been more efficient in other areas as well so...

Makes a lot of sense. I think we've kind of done the

NA route to death but I mean you're not just involved in naturally

aspirated engines and you've developed a turbocharged 2.2 K series

for an NSX time attack car which kind of alluded to already.

What are the challenges when you want to take this

really good factory K20 engine and instead

of making 300 horsepower aspirated, do you want to maybe make

700, 800, 1000 horsepower with a turbo on it? Where are the

new sort of weaknesses that creep in? So one of the first parts to go

to is obviously when you're going to target 250 horsepower per cylinder

the actual stresses that the components are going to see, forget

chasing air flow and power, just the physical design of components

needs to be so robust. So one of the key factors in the K22

that we designed is we went to an 89 mil stroke crank

sorry, 92 mil stroke crank but we managed to drop

the rod length by 3 mil and what that done is open up

a lot more room in the piston crown. So what

we've found on a lot of turbocharged engines that I've worked on through the career

is in my career is having a much thicker crown

obviously helps you to dissipate the heat and sort of gives

a lot more strength to the piston. So we worked

with the masters of piston design in Germany which is a company

called Pankel and they used a super computer to design

the underneath of the piston for this engine. So

it's not really even something that could be designed by the human eye.

It's been developed for a stress point of view.

This is sounding like an incredibly cheap process already.

It wasn't really the cheapest way to go but to try and do what we wanted to do. I think

the other bit people will probably question why we went to that extreme

but I think what we've sort of found since coming into the Honda market

is a lot of products that are out there are all designed to do

quarter of a mile sprints and effectively you're only doing

five gear changes. You've got five on-load points whereas when

we're doing time attack where we've got an hour's running a day

and one lap of brand's hatch we might see 50 gear changes

so it's the equivalent to 10 quarter mile

pulls on one lap. So I think the engineering that had to go into

just making this 1000 horsepower robust for track

laps or track use is just a whole different engineering

principle or level to be fair than just developing

it for the quarter mile. I think also in the UK we sort of expect

a time attack engine running a 1000 horsepower to complete

a whole season which could be up to sort of 80 hours of full chat

running whereas I think a lot of customers in America with their

quarter mile I don't know exactly the life that they'd get out but I think a lot of

people are seeing if they do two or three runs on one engine that's

a good engine. If I take it back to my 4G63

drag racing days I mean at one point we did improve

reliability and we weren't seeing failures but I mean that engine was getting stripped

and inspected and freshened up probably after 10 passes

so what's that, four kilometers of race use.

It's not a very economical process. I've always said

that it is harder though to make less power

for an endurance race application than it is to make insane levels

of power for six, seven, eight seconds in a row for drag racing

so the amount of time the engine is under stress, it's just chalk and cheese

absolutely completely different. I can't help but wonder where you saw

the shortcomings though in the off the shelf components.

I mean these days making 1000 horsepower in a K20

there's, I'm not gonna say it's easy but there's a pretty well trodden path

to getting there and there's off the shelf pistons,

con rods, crankshafts from a number of

companies that have been proven at that point. Is it just

come back down to again that sort of confidence that not only will it

make 1000 horsepower for one race meeting but it will actually do a season of

time attack? There is that but I think when you're running a time attack car

and you've got no limit on power and regulations, you've also got no limit on

aero and Suki which is Tegawa's time attack car, well I think we're

close to two times the amount of downforce that a current F1 car can produce.

So the point that you actually get to maximum downforce

the actual and one of these areas that people

maybe mine doesn't go to straight away which we see day in day out

on engine dinos is load and the amount of load that that engine

is under we've got four pistons with 250 horsepower

of cylinder pressure on top of each one literally hitting a brick wall

of load when they come on to maximum downforce and that

just creates a whole level of load on these components.

A lot of sort of 1000 horsepower I mean the number gets

about quite a lot. It's not really in a lot of

sort of applications or cars that that engine has come out of DC

Fives or EP3s. Generally I think they have

a dyno queen 1000 horsepower and what actually gets

run in the car is something different but then on a lot of tin top

applications that may have 800 horsepower they're not fighting this

wall of load with the aero. Generally they'll have a small amount

of aero on some of the DC Fives that I've seen in time attack

but hitting this wall of aero just come you know the

actual components that we've needed just needed to be another level in durability

effectively to suffer that life.

Yeah that makes sense. I should have mentioned earlier as well for those who haven't heard

the name Pankle, I mean it's not one that we see much in the enthusiast level

market but Pankle are well known for manufacturing components at the F1

level so this is a company that absolutely knows what

they're up to. The other aspect I wanted to dive into is

you mentioned that you went to a stroke of crankshaft, stock form there

in 86mm, stroke 86mm bore, what we call a square engine.

You've gone to a 92mm stroke to get to that 2.2 litre.

Conventionally the problem we have here, I mean it may not

be a problem but the knock on effect of this reduces our

rod to stroke ratio which is simply the ratio between the stroke

and the length of the conrod centre to centre. You mentioned

you went shorter on the conrod, I think you said by 3mm in order

to facilitate that thicker crown where conventionally with a lot of these stroke engines

we actually see that they retain obviously geometry, notwithstanding

the stock length connecting rod and then to get the compression height back

to where it needs to be, they move the wrist pin higher in the piston.

So the benefit there is the rod to stroke ratio with a

stroke engine would be superior to shortening the connecting rod.

Admittedly 3mm, it's not a massive amount

but you obviously saw the need for or you prioritised that thicker crown

over the rod to stroke ratio.

I was explaining, in my earlier career I've always done a V1

and a V2. So we made a V1 engine out of

slightly cheaper components and that retained the stock rod length

and what we saw trying to run up to these powers

and hitting the load sites that were hitting with the aero

is that the cylinder pressure was becoming so higher

that we were actually cracking pistons, we were cracking through the inlet port

and a lot of that was, some of it was to do with the physical pressure

on top of the piston and also some of that was to do with our heat

rejection. Obviously having more material there allows the heat

to dissipate quickly through the piston and ultimately into

the cylinder and into the cooling jacket and effectively the more material

that you can get in there and dissipate that heat as fast as you can

and the more durable it's going to become. So there is a, you know

I won't tell you the number but there's a size that I've always, a roll of thumb

that I've always gone to on piston crown thickness to try and get back

to that durability. So it's one of them unfortunately with all the

best supercomputers in the world there's always been a bit of real life experience

built back into that and like a surgeon now I've done it

that many times he's sort of just nowhere to cut now so a lot of it is

done without thinking nowadays with what we go to on piston crown

thickness and it's just a given but yeah. I mean speaking of not

thinking this is an element that most in the enthusiast market wouldn't

ever consider because we don't get to choose the thickness of the

piston crown. It's whatever came in the box of shelf stock pistons that

we just ordered from JE or Wiseco or CP or whoever it may be.

So that's quite interesting. I did have this issue

earlier on in my development of my 4G63 drag engines, obviously at that point

we're using a bespoke piston to my own design because nothing

off the shelf was really up to the task and we did see some piston

cracking fairly early on and we actually improved the reliability there

by increasing the thickness of the piston crown. Albeit I always

stayed at 2L for my drag engine so we weren't sort of balancing that

rod stroke ratio with a stroke of crankshaft. We had the flexibility to do that but

that overnight fixed most of the problems we were seeing with that.

Another element with the K20 is the sleeve design, the way it's sort of an open

deck design if you like. Not really an issue necessarily I guess with naturally

aspirated engines but as the cylinder pressure climbs with turbocharged

applications we can see problems with head gasket integrity with these liners

moving around, ultimately cracking. At what point do you need to consider

moving to a ductile iron sleeve or something like that?

I would say if you're even with an NA application, if your

budget extends to it, I would run a dart and liner or a sleeve block

mainly because even with the NA stuff on a lap

the borer valley of a standard borer or the movement

on a lap from the heat around it, you're constantly

giving away power like it's not a gaugeable thing and it's not

really a lot even with great crankcase pressure sensing.

You're not generally going to see it but just from what we've seen in the

past with standard bores, your OE piston

is constantly moving, your bores constantly moving and

there's 2% of gas lost that side then the actual calling

around the water jacket is not consistent so

your water temperature goes up and down, especially on

heat soaks, so when you stop at the edge of the box

and the heat soaks from every other component back you might then

fire up and your bores moved in this position

and you've lost a tiny bit here and there, so trying to

limit borer valley and bore movement is obviously on a

performance engine even in a spec, something that I would try and do

early on in the build. Yeah that makes sense.

Yeah again I think most people assume that the bore

stays round and it obviously doesn't, it's going to move

with cylinder pressure, obviously that's amplified with

the sort of cylinder pressures we see in a turbocharged application but still

in a naturally aspirated application it is going to happen and really we want

to try and retain that perfectly round bore because that's going to

help improve our ring seal and that in turn is going to account

for an improvement in our power. So just to jump

in there I think the other bit that people forget about is the

sort of silicon content that is in a lot of aluminium as well

and you might go and have four OE blocks and the actual

gap between the, or the room in between

the actual aluminium particles that the purity of the

material isn't always consistent batch after batch of engine

so to take that out and obviously one of the

first things that you do is go to a forged piston when you're building

and generally the reason that you do that is because the material quality is better

but much purer and obviously one of the big bits of an OE bore

is the material quality isn't great

and the pureness of the material isn't great so

what works on one engine from 98 on the same engine

in the year 2000 sometimes where they've

got the material from or has changed and just to

eliminate that and get to a datum point that you know works

I would always suggest going to the Dart and Sleeve because you know it is

a very pure material there's not a lot of silicon in the actual

material content and therefore your expansion rate is more consistent

and you just know where you are so. Well I think you should be

getting commissioned from Dart and I reckon that's a pretty

compelling sales pitch for their product. I'm not actually a dealer yet

so if they're listening. I just want to talk a little bit about head gasket

sealing with obviously naturally aspirated not usually a huge

concern, pretty low cylinder pressures relatively speaking

but you know as boost pressures climb this does become a problem

at what point does the head gasket

sealing become a limiting factor with the K20 design and what are your

workarounds for that. So we've found that we can run very reliably

up to 1.4 bar of boost on the standard head gasket

we used some speed factory I think they're 645

material head studs and just incorporating them

into the build with some ARP nuts as obviously give us

a much better head clamping across the gasket but yeah we

haven't really been able to push past 1.4 bar yet

all of the engines that I've worked on in my later earlier career

I've never run a head gasket. Everything has always been

a Cooper's ring or a Welles ring design and we would O-ring the

deck so what we're trying to achieve with the Honda as we move forward

in this turbocharged development is obviously to get back to

or incorporate the designs that I've had in my earlier

career and try and get a Welles ring and an O-ring seal

in that and actually eliminate the head gasket entirely but we're

just working at all HPP at the moment to try and get there

I think effectively we may end up with a wet liner and the amount

of material that's on the actual deck doesn't really lend itself to

having enough room to run like an O-ring around the side of the

deck so I think we'd I don't want to end up there but we might

end up with our own billet block design to actually get rid of the head

gasket and have the room on the deck to do set out the O-ring how we

want to set the O-ring out to seal the water jacket and also if we went to our

own billet block we could actually have a little bit more room on the outside

of the liner seal to incorporate the Welles ring. It's a lot of work

to go to seal the head gasket on but at the end of the day if you can't keep the head

on the engine it doesn't really nothing else really matters. No I think that's the

we've got all of our airflow working I think coming back to where

we've gone with the turbo you know our emphasis has been on getting the airflow

right on the NA and a lot of that work that we done on the naturally aspirated

engine when we incorporated that straight into the turbo engine

the turbo engine has been really efficient straight out the box without

having to run high boost levels because our airflow has been so good

and we've understood that on the NA it's just made us such an

efficient engine we're sort of close to the on a hot

lap we're sort of close to the 750 horsepower

mark at the moment with 1.4 bar so yeah as soon as we

can punch that boost up and have a head gasket sealing that's reliable

then you know I think the 1000 horsepower number on a track lap

is just going to reel itself in quite quickly. Yeah it doesn't sound like you're miles away

can you just elaborate on the terminology you use

there the Cooper ring or Cooper's ring, Wil's ring what exactly

do these look like to those who haven't seen or heard of these before

so it's a small sealing ring normally I'll have a standoff that sits

so you'd normally machine a little groove in the top of the cylinder

liner and then it's a normally a white gold material

with a vacuum inside it and that sits in the groove

on top of the liner and as the cylinder is bolted up it actually

crushes and fills the gap and it isn't just

the well's ring that does the sealing normally you would have

the liner set out of the bore you would have what we call a liner standoff

and the liner is designed in a way that it works like a damper

or a spring so even though when you look at it it's a big solid

piece it's actually designed to compress as the cylinder is

and obviously then getting your liner standoff is critical

so that as the head bolts down on the head bolts and crushes

the liner all the liners are at the same height and they've crushed back

to the block face so that's been the key bit in a lot of

blank sheet engines that I've worked on when we're sort of running big cylinder

pressure. These sealing rings you said you've got a groove

essentially machine around the top of the bore that they sit in, are they going to sit proud

of the top of the liner so those actually contact the cylinder

head first and then as the cylinder head's bolted down they deform.

The physics behind how these work is this sort of a case of under the heat and pressure

of combustion they will actually sort of expand and obviously

we like to think that the head and the block are nice and rigid and aren't

moving but under high cylinder pressure that's not the case which is why we have problems

with head gasket integrity so do these just flex enough, maybe it's

a couple of thousands of an inch to take up any flex between the deck surface

of the block and the cylinder head? So they do move, yeah exactly that

they do move with that but also as I described the actual liner

design is designed like a damper on the car and it is only moving

a thousandth of an inch and not what a damper is travelling on the car but

the actual liner is actually moving with the panting

of the cylinder head so it's quite hard to look at

when you've talked the head down to 100 newton meters and

it feels like it's going nowhere it's quite a weird analogy to think

that that head is actually panting on top of the block constantly and

the cylinder pressure is so hard that it's trying to force the head away and the head

actually lifts and comes back and lifts and come back so once you've got

the right liner design the liner is designed to move with that cylinder head

and that's where getting your liner standoff combined with the world's ring

is obviously the crucial part. Okay, alright I think we'll

leave that there because again we could probably spend another hour

talking about this topic but I think we've probably taken up just about

enough of your time and I'll move towards wrapping things up here.

We've got the same three questions Terry that we ask all of our guests at the

end of our podcast episodes and the first of those is what's

next in the future for you and Born HPP?

So we obviously set out to develop the Honda, we've ended up getting

quite a lot of intellectual property now and not just developing

the Honda but we've sort of built our processes up

at Born to move on and my passion is Japanese engine so

I think we'll use the same principles that we've put together and

just carry on developing Japanese engines. I think

36 now I've probably got 25 years left of my

career easily and I think moving through the years you'll just see

Born HPP developing Japanese engine after Japanese

engine. You've started with the bar set pretty high with the K20

what would be your next engine on the chopping block to develop?

So we've been given a 2 litre Mazda

MB engine to develop for a car manufacturer effectively

so that is actually the next engine not by choice of ourselves but

just because that's been put in front of us as a project but obviously

one of the most efficient engines outside the Honda has always

been the Evo engine so I think possibly the Evo engine will be

a market that we move into. I'm also a massive fan of the

Nissan Skyline so RB26's and bits and pieces

I'm sure you'll see some cams popping up on our website for them engines

too in the future so. Okay yeah makes sense I mean definitely

two of the more popular Japanese engines that are

continuing to go from strength to strength even sort of a long time

passed when they're actually offered in a production vehicle.

Next question for you Teri, is there any advice you'd give to a younger version of yourself

to help reach where you are today in your career faster and I'm struggling

to think what that advice could look like. It seems like you've really

landed on your feet at each step of your career so far but yeah

any insight? I would say on an overview once you've understood

the 1950s physics inside the box constantly

let your mind go outside the box and never be afraid to

ask questions. There's so much engineering that hasn't been explored yet

one of my best sayings is every day is a school day so

just keep learning and keep moving forward basically. I think we've sort of

pounded this message in time and time again on the podcast that

no one even knows everything when it comes to engine design, engine

development and calibration and that's what keeps me passionate.

There's always something, as you say, every day's a school day,

you've always got something new to learn so I think really important not to

sort of put your blinkers on and kind of think that you've learned everything there is to know.

There's always something around the corner, don't be afraid to share your experiences

with others in the industry, don't lock it down and think it's all sort of

you've got to keep it to yourself and keep it secret. Share and

you're going to end up learning from others as well and I think that'll expand your knowledge

really rapidly. Last question for today, if people want to follow

you and see what you're up to, how are they best to do so, what are your

website, social media accounts etc. So our website is

www.bornhpp.com and our Instagram's probably

one of the platforms that we're on the most and that is

born underscore HPP and yeah that's the best place to follow

awesome racing engine builds and tuning and everything that we get

up to really. Great and as always we'll put the links to those accounts

in the show notes to make it easy for people to find. Look Terry, really

great chat today, I really appreciate your time, this one has gone pretty

long but there was a lot to dive into and I still feel like we've only really

scratched the surface so I appreciate you coming on the

podcast and all the best for the future. Lovely awesome, thanks for having us

and I hope you've enjoyed this episode of Tune In

and don't forget by using the code podcast500 at checkout

podcast listeners can get a huge $500 off our VIP

package which includes over 40 current courses as well as a long

list of courses to be released in the future. As a VIP you'll also get

lifetime access to our members only, webinars and our community forum.

Lastly we'd love it if you could leave a review or comment on your preferred

podcast platform. Your feedback really helps us to reach a wider audience

which in turn allows us to continue bringing you more high quality

guests. That concludes our interview and before we sign off

I just wanted to mention for anyone who's been perhaps hiding under a rock

and hasn't heard of High Performance Academy before, we are an online training

school and we specialise in teaching a range of performance automotive topics,

everything from engine tuning and engine building through to wiring, car

suspension and wheel alignment, data analysis and race driver

education. Now remember you've got that coupon code, you can use

podcast75 at the checkout to get $75 off the purchase

of your first course. You'll find our full course list at

hpacademy.com forward slash courses. Important to mention that when

you purchase a course from us, that course is yours for life as well. It never

expires, you can rewatch the course as many times as you like whenever you like.

The purchase of a course will also give you three months of

access to our Gold membership. That gives you access to our private members only

forum which is the perfect place to get answers to your specific questions.

You'll also get access to our regular weekly members webinars which

is where we touch on a particular topic in the performance automotive realm.

We dive into that topic for about an hour. If you can watch live, you can ask questions

and get answers in real time. If the time zones don't work for you,

that's fine too. You're going to get access as a Gold member to our previous

webinar archive. We've got close to 300 hours of

existing content in that archive. It is an absolute gold mine.

So remember that coupon code podcast75, check out our course

list at hpacademy.com forward slash courses.

Revisited: Is Honda’s K-Series Really the Greatest 4-Cylinder Ever Made?

About this episode

Honda K series

Formula 1 engine

Mercedes F1 engine

Honda That Honda

Request an Explanation

Want to learn more?

Help improve this episode

More from Tuned In