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150: The Self-Taught Way: Building Wild Engines from Scratch

150: The Self-Taught Way: Building Wild Engines from Scratch

Tuned In Nov 05, 2025 116 min
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About this episode

Andre chats with Josh Vellman, a self-taught engineer known for his bespoke engine designs, about his journey from building a custom hill climb car to developing high-performance engines. They discuss the intricacies of engine design, including the challenges of creating a V6 engine with a unique 120-degree bank angle and the importance of 3D modeling. Josh shares insights on manufacturing processes, turbocharger specifications, and the significance of cooling systems. The episode highlights the balance between innovation and practicality in automotive engineering, making it a deep dive into the world of performance engines.

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Technical Too Afraid to Ask
Term

V8

"I appreciate the V8s or the V10s sounded incredible, but sounding good doesn't necessarily win you anything."

A V8 is a type of car engine with eight cylinders that gives strong power and good performance.

Term

V10

"I appreciate the V8s or the V10s sounded incredible, but sounding good doesn't necessarily win you anything."

A V10 is a car engine with ten cylinders that can produce a lot of power and sound impressive.

Concept

tube frame hill climb car

"he was deep in the build of a very custom, very bespoke one‑off tube frame hill climb car"

A tube frame hill climb car is a small, fast vehicle made with steel tubes for the frame, used in races up steep hills.

Concept

3D modeling and CAD software

"leveraging his engineering skills and engineering knowledge, which is interestingly almost exclusively self‑taught, but also his insane ability when it comes to 3D modeling and CAD software"

3D modeling and CAD let engineers draw a virtual car on the computer so they can see how it looks and works before making it.

Term

EFI

"we specialize in teaching people how to build performance engines, how to tune EFI"

EFI is a system that tells the engine how much fuel to use, making it run smoother and more efficiently.

Term

wiring harnesses

"how to tune EFI, how to construct wiring harnesses"

Wiring harnesses are groups of wires that link all the car’s electronic parts together.

Concept

fabrication

"we also cover topics on fabrication"

Fabrication means making the physical parts of a car, like cutting and shaping metal to fit together.

Part

bodywork

"Before we move on just in terms of that bodywork with it design what was the process you'll go through..."

Bodywork is the outside shell of a car, like its doors and hood. It keeps you safe and gives the car its look.

Part

panels

"Before we move on just in terms of that bodywork with it design what was the process you'll go through..."

Panels are the flat pieces that make up a car’s exterior, like the side panels or the hood.

Concept

tooling

"Before we move on just in terms of that bodywork with it design what was the process you'll go through in terms of to to make the tooling to produce these come farther panels."

Tooling means the special tools and molds you need to make many parts of a car, like stamping metal panels.

Term

variable valve timing

"So it probably will run variable valve timing which you don't have on the high boost but it allows you to account for the fact that the air gets thinner as you go up."

Variable valve timing lets the engine change when its valves open and close, helping it run better at low or high speeds.

Term

chassis

"We could talk to you another five years and you'll be back in the same situation but with a completely different chassis and engine combination is the problem."

Think of the chassis as the skeleton of a car. It holds everything together and helps keep the car stable and safe.

Term

engine tuning

"If you're a fan of the podcast and you're interested in topics like engine tuning, automotive wiring, performance engine building..."

It’s like fine‑tuning a car’s engine settings so it runs better or faster, similar to adjusting a recipe for the best taste.

Term

performance engine building

"If you're a fan of the podcast and you're interested in topics like engine tuning, automotive wiring, performance engine building..."

It means building or upgrading a car’s engine so it can go faster or handle better, like putting in stronger parts.

Term

lean

"Does this kind of tune things on its heed in terms of being able to run a lean if your ratio, but still make great power?"

Lean means the engine is using more air and less fuel. This can make it run better if done right.

Term

dynamic compression ratio

"Yeah, and giving you a lower dynamic compression ratio by closing the valve early..."

Think of it as how much the engine squeezes air and fuel together before ignition. A higher ratio can mean more power, but it also needs careful control to avoid engine damage.

Term

direct injected engines

"With production, direct injected engines, one of the problems that is pretty well known."

Direct injection means the engine sprays fuel straight into each cylinder instead of mixing it with air first. It helps engines run better and use less fuel.

Part

exhaust manifolds

"and exhaust manifolds between the two cylinder heads"

Exhaust manifolds are metal tubes that gather the hot gases from each cylinder and send them together to go out of the car.

Part

intake manifolds

"even with the intake manifolds"

An intake manifold is a part of the engine that takes air from the air filter and sends it to each cylinder so the engine can run properly.

Term

damping

"you can do without it, embracing, because the vibration isn't the end of the world, but you still need an element of damping on the crankshaft and certainly on the camshaft."

It’s like putting a cushion around parts of the engine so they don’t shake too much, keeping everything running quieter and more reliably.

Part

crankshaft

"but you still need an element of damping on the crankshaft and certainly on the camshaft."

Think of it as a big metal rod that spins inside the engine, turning the up-and-down motion of the pistons into the spinning power that moves your car.

Part

high boost head redesign

"[3604.0s] I was effectively trying to see, well, how they done it, how would I do it, but in Billet"

A high‑boost head is a part of an engine that lets it run with more air and fuel, making it faster. Engineers change its shape or materials to keep it strong when the pressure inside is very high.

Concept

OE engine world

"[3806.0s] and in the OE engine world, [3809.0s] a good example of that"

This means the engine is built by the car company itself, not a third‑party maker. It follows the exact rules and parts the factory uses.

Term

rod to strike ratio

"[4007.0s] Is the rod moves through its cycle? [4009.0s] It's effectively, look at it as a triangle, right? ... [4015.0s] And you want to try and minimize that angle,"

In a car engine, the connecting rod pushes the piston up and down. The rod-to-stroke ratio tells how long that rod is compared to the distance the piston travels. A higher ratio means the rod stays more straight, which can make the engine run smoother.

Term

turbo

"But to get to that much boost on the turbo, you have to go through a whole range of low levels of boost"

A turbo is a device that takes exhaust gas and uses it to push more air into the engine, making it stronger.

Term

pressure sensors

"send it to pressure sensors and temp sensors"

Pressure sensors check how hard fluids or gases are pushing inside parts of a car, like the oil in the engine. They help make sure everything is working correctly.

Term

temp sensors

"send it to pressure sensors and temp sensors"

Temp sensors keep track of how hot parts of the car are, like the engine coolant. They help the car stay cool and run smoothly.

Term

aluminium 6061

"So it's already been so with aluminium 606-1, which is sort of your run of the mill machining aluminium, that normally comes in it in a T6 format,"

Aluminium 6061 is a type of metal that car makers use because it’s strong, light, and easy to shape into parts.

Term

3D printed part

"[4551.0s] If you think about a 3D printed part that's got layers, [4555.0s] it's very easy to break it across the layers,"

It’s a part made by printing it in layers, like using a 3D printer instead of cutting or molding it.

Term

billet aluminium

"but when you're machining a piece of billet aluminium like this, I can only assume it's putting a lot of heat into the aluminium"

Billet aluminum is a solid piece of metal that you can cut or shape into parts. It’s lighter and stronger than many other materials, so it’s popular for making things that need to be both strong and not too heavy.

Term

heat treating

"I might have missed it, but do you do a final heat treat after the final machining, or is that it?"

Heat treating is when a metal part is heated and then cooled in a controlled way to make it stronger or harder.

Term

line honing

"...such as the line honing, the main bearing tunnel and the block..."

Line honing is a special polishing step that makes the inside of engine cylinders smoother, which helps the engine run better and last longer.

Concept

Formula One

"[5219.0s] but I mean, you'll see every weekend on Formula One [5221.0s] as well where they go."

Formula One is the top level of car racing, with very fast and advanced cars that are built for speed and performance.

Part

cylinder head

"How difficult, how complex is it to keep the cylinder head sealed to that block?"

This is the top part of an engine that holds the valves and spark plugs. It needs to stay sealed so the engine runs properly.

Part

block

"to that block?"

This is the big metal part of an engine that holds everything together. It needs to be strong so it doesn’t break under pressure.

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