Edelbrock is a company that makes aftermarket parts for hot-rodding and performance engines. Here, they’re coming on to talk about intake and carburetor upgrades.
An intake swap means changing the parts that bring air (and fuel) into the engine. People do it to try to make the engine run stronger and feel more responsive.
The intake manifold is the part that channels air (and often fuel) into the engine’s cylinders. Changing it can help the engine breathe better and make more power.
A tunnel ram is a special intake manifold that sits high on the engine. It’s meant to help the engine breathe better at higher RPM, but it can make the car less happy at low speeds unless it’s tuned right.
“Big block” is a term for a large V8 engine. The host is using it to set the scene for a muscle-car build where big intakes and carb setups make sense.
The Dodge Charger is a famous muscle car from the Dodge brand. In this story, the host is talking about a 1971 Charger and how a big intake setup was used to make it stand out and change how the engine runs.
“650s” is shorthand for carburetors sized to flow a certain amount of air. If you use carb sizes that are too big for the engine, you can end up with too much fuel and dirty spark plugs.
The McLaren 650S is a modern supercar built for very fast performance. It uses a powerful engine and advanced engineering to make it accelerate quickly. People may talk about it when discussing how engine settings and fuel delivery affect how the car runs.
Term
Holly 390s
“Holley” is a carburetor brand. The “390s” part is basically the carb model/size they used, and that choice affects how much fuel the engine gets.
Fouling plugs means the spark plugs get dirty with deposits. When that happens, the engine can misfire or run badly because the spark can’t do its job.
Brand
Victor Jr.
“Victor Jr.” is an Edelbrock intake-manifold product line name (commonly associated with dual-plane intakes for V8s). In the segment, it’s used as the specific intake swap that changed the engine’s torque characteristics.
A single-plane intake is an intake design that usually helps the engine make power higher in the RPM range. In the episode, they’re comparing it to another intake style to show how it changes the car’s “feel.”
The torque curve is a chart of how strong the engine feels at different engine speeds. Changing the intake can shift where the engine makes its best pulling power.
“RPM range” refers to the engine speed band where a given intake/carb setup is designed to work best. Intake runners and carb calibration can be optimized for low, mid, or high RPM, so pairing mismatched parts can make the engine feel flat or stumble outside the intended band.
This means the intake and carburetor should be chosen to work well together. If they’re not matched, the engine can feel weird—like it doesn’t respond right when you rev it.
Peak torque is the point where the engine has its strongest pulling force. When the intake system is timed well, the engine can fill its cylinders more effectively at that RPM.
As the engine valves open and close, the airflow doesn’t just move smoothly—it creates pressure pulses. If those pulses show up at the right moment, the engine can breathe better.
Here, “supercharge” means getting more air and fuel into the cylinders than you’d otherwise. The idea is that the intake system is timed so the engine gets a helpful pressure boost at the right moment.
The plenum is a chamber in the intake system where air collects before it goes into the engine. It helps manage pressure changes so the air flow into the cylinders is more controlled.
Concept
Hemmholtz theory
This is a theory about how the intake system can act like a tuned air instrument. By choosing runner/manifold sizes, you can make the engine breathe better at certain RPMs.
Long runners are longer intake tubes. They tend to help the engine make stronger torque at lower and mid RPMs because the airflow timing lines up differently.
Primary and secondary are like two steps of airflow/fuel delivery. The engine gets the smaller amount first, and then the bigger “second stage” kicks in when you need more power.
Valve overlap is when the engine briefly opens both the intake and exhaust valves at the same time. That timing can affect how well the engine breathes and how it responds.
When the intake valve opens, it creates a kind of “pull” that helps the engine draw in air (and fuel). The stronger that pull is, the easier it is for the carburetor to deliver the right mixture.
A dual-plane intake manifold is an intake design that splits the airflow paths into two sections. That split changes when each cylinder gets air, which can make the engine feel stronger in the lower-to-mid RPM range.
An induction event is when the engine’s intake valve opens and the cylinder pulls in air (and fuel). How often and how evenly those “air-pulling moments” happen affects how strong the engine feels.
“Peakiness” means the engine makes its best pull in a narrower RPM range instead of evenly across the whole rev range. Intake design can shift where that strong area happens.
Cam timing is how the engine’s valve timing is set—basically when the valves open and close during each rotation. That timing changes how the cylinders fill with air.
Throttle is the control that tells the engine how much air it’s allowed to take in. More throttle usually means more airflow, which changes how the engine performs.
“Cubic inches” is how big the engine is, based on how much space the cylinders can move. A bigger number usually means the engine can breathe more and feel stronger when you accelerate.
A carburetor is a device that mixes fuel with air so the engine can burn it. Intake parts have to match it, because they control how the air and fuel get delivered to each cylinder.
Term
winded manifolds
They’re talking about a style of intake manifold that changes how air travels into the engine. Different designs can be better for different kinds of driving or engine behavior.
Term
RPU
“RPU” sounds like a specific intake-manifold option or design the shop used to make. In this clip, they’re saying they stopped using it in favor of a more proven performance design.
Term
performer design
They’re referring to a popular intake-manifold style that became the go-to for performance. It’s basically the “proven” design compared with more unusual earlier ideas.
“Single plane” describes how the intake manifold is shaped to feed air to the engine. That shape can change how the engine feels at different engine speeds.
“Performer RPM” is the name of a specific intake-manifold product they made. It’s designed to help the engine breathe better when you’re driving at higher revs.
They’re talking about engines that get extra air pressure, not just sucking in air normally. That can make intake design matter a bit differently than on naturally aspirated engines.
A bell mouth is a flared shape at the entrance of an intake tube. It helps air flow in more smoothly and can keep one cylinder’s airflow from interfering with another.
A turbocharger uses exhaust gases to spin a compressor that pushes more air into the engine. More air can mean more power, but the intake still has to flow efficiently.
Naturally aspirated engines don’t use a turbo or supercharger. They pull air in just by the engine’s normal suction, so intake design can still matter for airflow.
Runner length is how long the intake tubes are before air reaches each cylinder. Changing it can make the engine feel stronger at different engine speeds.
A “circuit” is like a different fuel-supply strategy inside the carburetor. A “four circuit” carb has multiple ways to meter fuel so it can be tuned across more driving conditions.
The transfer slot is like a small “early fuel” pathway. When you start to press the throttle, it adds fuel before the bigger fuel systems fully kick in, helping the engine run smoothly.
Idle circuitry is the carburetor’s fuel system for when the throttle is barely open. It’s what keeps the engine running smoothly at idle before the other fuel stages take over.
The intermediate circuit is the carburetor’s middle stage. It helps feed the engine during the transition from idle to more throttle, so it doesn’t hesitate or run poorly while you’re moving off idle.
Over-carburetting is when the carburetor is giving the engine too much fuel. That can make the engine run rich and behave oddly, especially during throttle changes.
Idle air controls adjust how much air the engine gets while the throttle is basically closed. Changing that air changes the fuel/air balance at idle, which helps you set a smooth idle.
Four-corner idle is a tuning approach for carburetors that tries to make the engine behave smoothly at several idle-related situations. Instead of fixing just one setting, it balances multiple spots so it runs right when you’re just off idle.
A main jet is a small fuel-control part inside a carburetor. If you change it, the engine either gets more fuel (richer) or less fuel (leaner) when you’re driving harder.
Air-fuel is the balance between air and gasoline the engine mixes together. Carb tuning tries to keep that balance right so the engine runs cleanly and doesn’t stumble.
A power valve is a carb part that adds extra fuel when you’re asking for more power. It helps the engine avoid running too lean during hard acceleration.
Power enrichment is the carburetor’s extra fuel delivery during acceleration or high load. The idea is to temporarily enrich the mixture so the engine makes power cleanly and avoids lean stumble while the throttle transition happens.
A choke helps a cold engine start by making the fuel mixture richer. The conversation is about whether you can remove it and still get good starting and smooth running.
Jets are small openings in the carburetor that control how much fuel flows. If the fuel level changes, those openings may not work the way they’re supposed to.
Jet extenders are like longer parts that help keep the carburetor’s fuel jets covered with fuel. That way, the engine gets steadier fuel even when the car is turning hard.
Term
corner cuts
Corner cuts mean taking a tighter line through a turn. Turning harder makes the fuel move around more inside the carburetor.
The Plymouth Barracuda is a classic muscle car from the 1960s. A 1967 Barracuda is one specific year of that model, and people often talk about the engine parts on these cars, like the carburetor. It’s the kind of car that can be kept as a project or restored.
Fuel injection is how many modern cars deliver fuel using electronically controlled nozzles. In this episode, they’re saying carburetors can still work even though fuel injection is the newer standard.
A dyno is a machine that tests how much power an engine makes. A “dyno shot” is basically the proof run showing the results.
Concept
carb guy
A “carb guy” is someone who knows how to work with carburetors—like picking the right parts and getting the tune right. The host says you can learn it with guides and practice.
Holley makes performance intake parts, and “high ram” is a version of that intake design that sits higher so it can fit under the hood. It still uses the same long-tube idea to feed the engine. The main point is getting the performance setup to physically fit on the car.
Term
LSXR manifold
An LSXR manifold is a type of intake manifold for GM LS engines. It’s designed so the long intake runners can fit under the hood. The idea is to keep the runner benefits while reshaping the tubes for packaging.
LIVE
It is the two guys who are at Podcast East, Kevin Byrd, and I'm Willie B. And today we're
going to learn something. Man, today it's great. It's pretty impressive when you talk
to a guy in the industry that goes, you know, I've been here 42 years. And I'm like, ah,
he got to know a thing or three. This guy is going to be, this is going to be awesome,
man. Yeah, for sure, man. This is, you know, we're
talking engines making power and how the stuff works to make that power. We've got Brent
from Edelbrock coming on in just a minute. And I'm pretty excited because you don't
get somebody with 42 years experience that often to be able to jump in there and probably
answer just about anything we can come up with. Yeah, man. No doubt. And what's wild
is a lot of people, they, I feel like an intake for so many people, they think and view their
perception of an intake is, well, it's not the place for performance. It's not the place
to gain really a lot of performance and so forth. And most people, if you were to take
a, you know, you know, eight out of 10 automotive enthusiasts and car guys out there, they tell
you that the carburetor is dead. I'm going to tell you it is not. And reasons for that
a little bit later in the podcast. Man, exciting to talk about some of the subject matter because
let's be honest, the technology nowadays in an intake is vast. It's wild. The opportunities,
the performance where you can, you know, really increase performance and increase how the car
feels and what kind of performance you're getting out of it with an intake swap. It's wild, man.
And let alone stacking on top of that, a nice performing carburetor, you got a wicked cool
combination. Well, talking about performance carburetors, that's really what I'm excited
about today because right Edelbrock just totally jumped in the game with like a legit performance
sort of targeted carburetor, right? Everything you kind of think of with that H word, but man,
they put their own, you know, whatever is 50 years or 100 years of experience in with all kinds of
features that I can't wait to dive into a little bit later, but let's start with that intake
manifold. Now, Willie, going back in time, man, tell us what you were running.
I picked up one of the new Edelbrock cars right here, man. I wanted to bring the show and tell,
so you could just, well, I wanted to just see my man Kevin lick the screen because I know he will.
When he sees his carburetor, it's that good, man. It is awesome. I'm looking at the screen right now.
So check out this, man. When you're going for cool points in the late 80s, only one thing would
harness all of them. Only one thing could grab attention from a block and a half away.
Only one intake would have people staring, pointing in disbelief that you were pushing around a
tunnel ram. Oh yeah. That's right. On a big block dodge and a 71 Dodge Charger. Now look,
I was smarter than the average because as a kid, most people make the mistake of over fueling
a tunnel ram. They'll put two 650s on it or something. I just had a 440. It wasn't even a
stroke 440 at the time. I had a big cam in it, some nice heads, but I did put a tunnel ram on
there. I took two, I'm going to say the H word, Holly 390s, and I flowed all the square edges off
of them, did a lot of grinding work and cleaned them up. And you know what? The car, if I, if I
lapped it around my college campus, it would foul plugs about every three to five rides.
But if I stayed in that thing, man, it would, it would run them for at least, you know,
two months out of summer before a plug change, which is saying a lot. But yeah, man, useless
intake. It's just absolutely hideous and you're, you're utterly ridiculous for running that thing.
But man, cool points would come if I'd have a whole trunk full. I would give people that wrote
around in Ford's extra cool points because I felt sorry for them. That's how many cool points I had.
It's like bingo cards, but it was cool points. You know, we live and we learn, huh? Too big a
cam, too tall an intake, too crazy an intake. Like a stock 440 need to be 8500 RPM. Yeah, that works.
Well, this is where we can share some of that knowledge three ways today. So yeah, I had a
first, you know, small black Chevy had a single plane intake. And man, when I went to the Victor
Jr. back in the day, you know, dual plane, boy, did that pick up the bottom end, man, that thing
just become fun. Wow. I was like, I was really amazed at just that one swap, right? How much
just moving the torque curve around. And so that's why we've got Brent here, man, because he's
playing a little bit about what's going on in that intake. And then again,
can't wait to get on that carburetor conversation. Amen. You constantly hear people make the mistake
of not pairing parts in the same RPM range that works symbiotically. And man, lesson learned.
Our boy today will teach us the pros, cons, the has and has nots of intake, carbs and more.
It's the two guys right podcast, Kevin Bird, with a B, we're back after break.
It is the two guys right podcast, he's Kevin Bird, I'm Willie B. And man, we're about to learn
something we have Brent on from elderbrock carburetors. And Brent, I got to tell you, man,
when you said you've been there for 42 years, man, you've seen some massive swings in technology.
And I bet, man, I bet to watch if you just fast forward, you know, and see in high, you know,
in high speed, the changes on top of an engine when it comes to intake and carbs over the last
several decades. And you've been at the helm of all of it, watching all these changes,
watching this technology grow to what we know and can trust today. And man, what an amazing career
that has to have been for you, man. Just amazing. It's got to be off. Congratulations.
Well, thanks for having me here today. This is going to be great fun. You know, it's interesting
when you said how manifolds have changed over the years. I think about when I started,
the company had a manifold called an SP2P, because we were in the middle of a gas crisis.
So the whole goal was to create a manifold with such small runners that you top out at like 3000
RPM. And it would be really snappy. And so the company sold a lot of those. The problem was,
the gas was not, crap, right? Right, right, right. And then if they ever did go past
3500 RPM, they'd hit their nose on the steering wheel. It wasn't great. It did get great gas
while it drove. I put one on my mom's car. How about that? There you go. Funny, man. It sounds
like what moms would put on kids' cars to keep their foot out of the throttle. It's, it's wild,
man. You look at these intakes as you were coming up in this, in this wild world, what were big
changes that you witnessed and kind of walk us through how an intake works. I think people would
be, you know, well versed if you just kind of broke down an intake's job and how it's supposed to do
that, how it's supposed to function and what's, you know, what are properties thereof that make
it perform better or worse? Good, good, good. You know, it's funny, like I was thinking about this,
and you put your hand over an engine over a carburetor, and you feel this constant stream of
air, right? Everybody thinks the air comes in, goes through the carburetor and just goes right
out to the cylinders. And the reality isn't really that. If you think about it, the valve
closes, right? So the air gets into the runner, goes through the carburetor, it gets in the
plannum, goes through there, gets in the runner, and it has to stop. And then the valve opens,
the piston drops, and it pulls the air along with it. So if you think about it, like when you're
making peak torque, it's because you fill the cylinder the most. So what Edelbrock's specialty is,
is setting the velocity in the runner or the speed of the air and the fuel through the runner
to ideally fill the cylinder. And that turns out to be like 400 feet per second at peak torque.
So you think about it, the air is stopped, and then it gets up to 400 feet per second.
So you're talking a football field and two end zones, bam, in a second, right? So it's really
fast. And then it stops again. And then it does this again. So what that does is it sets up these
pressure waves. As soon as it stops, you know, the air is all crammed against the valve, and then
it starts to relax. And that pressure wave goes back up the runner, and it sees the plannum,
and the plannum is higher pressure, because there's more of it there, and bam, that pressure wave
goes back down the runner. And you're trying to time when that pressure wave hits the valve again
to kind of supercharge the engine and put more air and fuel into it. You ever seen those trains
in Japan where they shove everybody in, and they're pushing them in before the doors close?
It's kind of like that. You got everybody shoved in, they're pushing, they're pushing.
You got a guy in that manifold just shoving in those air molecules. And then the doors close
real fast. William, right? Get on your way, and then, you know, somebody else is shoving.
It is amazing that it stops. Like a stop sign on a turn three of a NASCAR oval. It's like what?
It's wild to think of it that way, but it's truly what happens. And you think about it,
those poor people are about to get the heck beat out of them when that piston comes up, huh?
Well, you make a good point on people's perception, right? Because you think there's
just air coming in. But if you're sitting in the plannum, you got eight runners, all one at a time
opening. So you think about, I got to go this way. No, I got to go that way. I got to go this way.
And it's all these waves bouncing back and forth. Now, when you shut it and take valve,
right, and you start that wave up the runner, it's bouncing back and forth. Do you know how
many times it's bouncing back and forth before the next cycle when it opens? Okay, so let's
think about it. It's on a dual plane. You've got like a seven inch long runner, and it's got to
make like three or four passes, basically. So it's banging back and forth three or four times,
and then you're catching it on that third or four. But that's the with EFI and new, you know,
you guys are talking about new designs and all that. Now you've got an 11 inch long runner.
And so you kind of cut the number of trips in half. So you can kind of do it in, I don't know,
octaves sort of ways, right? Yeah, it's kind of like that. So if you can't get the 11 inch,
you get some octave that you still get the timing right, but you've traveled more times up and down.
Yeah, right on. That's why I said the Hemmholtz theory, yeah. So it has a little overlap with
music and, yeah. All right. So for a lot of people that don't understand like a single plane or a
dual plane, could you explain that a little bit and what's happening dynamically for them? Sure.
And also, the difference between long runners and short runners, I think there's,
people can learn a lot from there and how you can tune tune with the length of those runners
you're talking about. Right. So like when you when you get near the right range, like if you're
down with a three inch runner, there's hardly any tuning available. But if you're in that,
you know, five to nine inch runner length range, it's like about I want to say a half
inch is about 500 rpm of torque peak somewhere along that there's a ratio. Yeah, right, right.
And it's not much. So going back to the dual plane single plane thing. So you think about it,
a dual plane is taking a V8 engine and turning it into 24 cylinders. And then they're feeding
each four cylinders off of two barrels of the carburetor. So there's a primary and secondary
for four runners, and there's a primary and secondary for the other four runners. So what
happens is you've got, you don't have that little overlap of like the 57 runners
hitting at the same time, you've got a gap in between them. And so the rush of air or the signal
from the air from the valve all that motion turns out to be stronger, just because it's
only seen two barrels of the carburetor, instead of four barrels of the carburetor. And the way
it adds up the runners, the separation of each induction event, you actually get a little more
peakiness in a dual plane than in a single plane. But then what happens on a dual plane is now
you get up to, you know, 6500 past that, you're trying to feed those runners with just two barrel
carburetors basically, you know, two barrel for four runners. And where on a single plane,
you've got all four barrels of the carburetor. So, you know, one cylinder hits, and then,
you know, 180 degrees later, another cylinder hits. And since the cam is like 240 degrees of
timing, you get that 60 degrees where they're both pulling, well, now they got, you know,
two, all four barrels to pull off of, and that's ideal. And then the other thing with a dual plane
is it's convoluted in the way the runners are laid out, like they have to take more turns and more
kinks in the runner and all that. And a single plane is just this beautiful, you know, glorious
just a big throat down to his gut. Yeah, but a big trade off on where and how you're making that
power, right? If you want that bottom end torque, you take the torturer's path, but you've got the
smaller, you know, it's a stronger signal for anybody trying to understand what that means by
a signal, right? Take a straw and blow in it, or, you know, try to maybe suck it into whatever to
suck something off the table. You know, it's, it's pretty notable. I'll take a four inch pipe
and blow through it, and it's kind of lost in there, right? So you don't have the signal from
that open valve going, all right, give me some air. Now, right? So that sizing of the port,
the runner and the length, that volume, right, that's kind of that signal. And yeah, when you've
got just a big open port, yeah, higher PM when you're just ramming air through there, you got
plenty of signal, but coming off the line, you're going to be dogging, right? So pick your poison,
placement comes into play. Yeah. Placement comes into play. Just go bigger cubic inches. There you
go. Exactly. I can't argue with that. More snap, more cubic inches. Yes, yes. You know what's
fascinating about that? I, our pattern maker or the people who make the tools, we had a pattern
maker, Harvey Hartman, and he used to be out in Knott's Berry Farm when it was all farmland out
there. This is like the late, fit 1950s, and Vic senior would come out to visit him and they
designed manifolds. You know, Vic would tell him, I want this, this on this flathead manifold.
And Vic senior explained it like you with the straws. He says, Hey, if you want to drink a Coke
and you picked a little section of a garden hose, would you be very successful?
No. And if you picked like a coffee stirrer, you know, just a little skinny thing, would that
work? No, you got to get the right size straw. And now you've got enough energy to pick that up
and to, uh, you know, fill your Coke. Yes. Well, it's interesting, you know,
because you're really constrained by package. You got this carburetor and you got these four,
you know, these eight runners. So you're kind of constrained. So what's interesting, like,
I don't know, winded manifolds kind of start settling down, I don't know, 80s, 90s.
Yeah. Yeah. There is a lot of settling down because we settled into that performer design in
the 1980s where we kind of passed up that, uh, you know, the RPU and all the crazy stuff,
all those tiny single planes, you know, it got to be the performer. And then, uh, Vic came into
the office one day and he says, man, I was at a car show and this guy told me, I like the
performer, but I need something taller. You know, I just want something to look better.
And, uh, that's when we made, uh, the high rise, which we call the performer RPM. Thank you.
Oh yeah. Yep. Had a few of those. I was running right there. Yeah. And then the air gap just
had that extra cool factor to it. Yes. Yeah. Right. It's just like, let's make this look
trick now. And that's, you know, yeah, that was kind of the go to there. Yeah. No doubt.
How many of those intakes did you guys sell, man? Cause every, everywhere you turn,
everybody had that same intake. That was it. That's the only thing that was on cars, you know,
that were driving out of the street was amazing. We have this machine and Torrance in our factory
where you'd load up a raw casting on this end and it would start doing some stuff and it would
move to the next station and do some other stuff and move to the next station. And it worked its
way all around there and every minute and 40 seconds, one came off the other end and they
washed it and put it in about five days a week. Wow. So yeah. It's a lot of parts.
So popular nowadays. What have you found in intakes that is notable or is it because it's
just, it's pressurized now. So maybe design isn't as critical as it once was. You tell us
in boosted applications, where or is there a certain path or technology that's proven to be
better than, than other things that we were thinking. Man, those, you know, in boosted
applications that like you said, the boost just fixes all ills. Just dominates. But it is, it is
still a pressure drop because you got high pressure here and low pressure in the cylinders and you're
trying to rush as much air through there as possible. But realistically, you want a nice
large area in the plenum surrounding the runner. In other words, like if you could make a nice bell
mouth on each runner so that one runner isn't, you know, feeding off the other,
taste stealing from it. It's that kind of isolation there. That's really good. And then,
you know, if you can't have more runner length, that's good. But if you don't,
it seems to be pretty fine. Add more boost.
I will take that back. I was thinking more along the supercharger line and the turbocharger line
that is still seemed to like the longer renters, you know, are kind of a normal and it seems like
a manifold that works well. Normally aspirated also works well with the turbo. I'm talking like
the front mount throttle body. Yeah. Yeah. Yeah. Well, there, you know, there's making some of them
with just incredibly short runners that package real nice front feed. And they're starting to,
you know, obviously they probably rent some in a and went, Oh, shoot. Yeah. They're starting to come
out with more taller ones and try to get them to package under the hood. Yeah. I notice you guys
have your like LS crossram, which looks like it just checks all the boxes like from a performance
function, you got the runner length, you got the two plenums, the twin throttle bodies. Now,
controlling all that might be a little bit, but seems like from a theory, that one kind of hits all
the what you'd likes almost, maybe not for boosting, but pretty sexy looking piece. Thanks.
No doubt, man. We're up against a break. But when we come back,
this is the conversation that we've been really excited to get to. They have dropped a new carburetor
that is, oh man, it is safe to say it's a piece. And it's a piece that you guys want. It is awesome
in every way. It's got adjustability. We thought other carburetors in this game had adjustability.
This thing is unbelievable, man. It is, it is badass in every way. This is some of this way cool
Kevin Bird, Willie B. And this is the two guys garage podcast. We're back after the break.
It is two guys garage podcast. He's Kevin Bird. I'm Willie B. And now let's talk about this.
In my hands, ladies and gentlemen, this is something that's going to be a game changer.
If you have not seen the VRS carburetor, it is God, you guys did something special here, man.
Really? Yeah, this thing is full of tricks, man. You know, if you're familiar with, you know,
the H word, you'll feel really comfortable. Yeah, you'll feel really comfortable with this unit
because it visually kind of has a lot of the same type of stuff, right? Metering blocks,
you got your site windows, but it just the features you guys have stacked one after the other
is pretty incredible. Now from your, your opinion, man, what, what are some of the things that you
think really shine on this? Like the four circuit kind of jumps out as like that could be interesting,
right? To get that much level of tunability across the spectrum. Yeah, that's it. I think that the
intermediate circuit, you know, it's, we had a long time ago, I'm saying the 70s, before I started
working there, there was a guy who worked in the diner room, Murray Jensen, and Murray had, he created
a whole side business of adding intermediate circuits to Holley carburetors. In fact, Edelbrock
sold a calibrated Holley carburetor as part of when we, back when we were at warehouse. So this
isn't, that's much of a stretch from where we were. But yeah, when we were benching, you know,
shooting, getting ideas for this carburetor, benchmarking it, looking at what we wanted to do,
the idea was, well, where do you want to be? You want to have a two-circuit and a three-circuit,
or how about a four-circuit? Oh, more? That's the first, the first thing I noticed about it.
First thing is, yeah, are the four circuits, and that means more tunability for everybody out there.
You can really lean on that lean mixture and get it right. Yeah. So what it does is, you know,
if you flip the carburetor open, and you're, you're looking at what happens as you open the
throttle blade, you'll see, you know, the transfer slot, you know, so the transfer slot is pretty
much closed. It's got a little bit of gap in there to keep the fuel moving right at idle. But as soon
as you crack that throttle blade open, now you're feeding off the transfer slot, you know, you don't
really have much pull on the mains yet. But as you crack it more, now you see the tube for the
intermediate circuit, and it's starting to feed fuel. And that's something you just didn't have
before. You'd have that large gap between, you know, kind of the idle circuitry, and then you'd
have to get the throttle all the way open. You'd have the accelerator pump coming in, obviously,
to add fuel until you got on the main circuit. Well, with the intermediate circuit, now there's
a lot of times where you're not really squirting off the accelerator pumps, you know what I mean?
You're kind of in that little gap zone, and the intermediate circuit feeds that. So that's why,
you know, you'll see a lot of videos and things online of people over carburetting a car with a
VRS when they're going like, this runs too well, like it shouldn't be doing this.
Well, what's cool is it's got the out of the box kind of base calibration that you could
just almost bolt on and go. But for all of us that like to, you know, really eke out everything
and dial it in, you have so many knobs you can go and play with. Yes, right, right. You mean,
you know, you could, the first thing you do just like any carburetor, you know,
you adjust your four-corner idle, you get the idle set. We have those auxiliary idle airs
on the side of the carburetor. Yes, you're not trying to open your blades like on a big cam,
right? You got a big cam, got low vacuum, right? You're trying to get the thing, the idle, you're
cranking it up, and you're getting into your transition before you want to, right? Just that
idle. So you've got, right, the ability. Yeah, then you have a flat spot because you open it up,
and you know what? That's a quick way to lean out the idle too. It's kind of funny, you know,
if you add more air because it's just air coming in through, you know, the top and then dumping
into the manifold. So it kind of leans out your idle too. So you're playing around with the
four-corner idle and then you've got that. So those are the, like I said, those are the basic
adjustments to start with. And then if you're running people, it's the main jet, you know,
it's just like any carburetor, like that's one first place to start is the main jet.
And it does, the fuel curve is really flat. A lot of people have been impressed with that,
how all the way through the RPM range, low RPM to high RPM, if you're at 12-2, you're 12-2 across.
If you're at 12-7 or 13-7, you're that way all across. And then the main jet just kind of lowers
that or raises it, however, you know, if you add more fuel or take it away. Yeah, consistency
of air fuel across that, whatever, cruise space or, you know, separate from when you get in your
power valve kind of thing, right? That's where you've got that consistency. So you're not going
up and down and chasing foul plugs or leaning out or lost power, right? All those things.
Good point. Yeah. That's right. I was thinking wide open throttle, but you're right. We've got
two power valves. So when you're in that transition, you know, you got the lean cruise and now you
kick in the throttle and you get below five and a half inches of mercury and boom, here comes more
fuel. And not only can you change power valve, industry standard power valves, by the way,
you can change the power valve out. We have screw in emulsions behind it, or not emulsions, jets.
It's that small jet. So you can change the amount of fuel that comes in on the power enrichment
and the timing of it. Oh, timing too. The timing is the power valve itself, like what vacuum
it's coming in. Oh, yeah. Okay. But that's with the power valve itself.
And then on top, you know, if you are, if you're drag racing and you're in the staging lanes and
the weather changes or something like that, we've got all the bleeds on top of the carburetor,
and you can make really fine adjustments there. You've got things like
throttle position sensor capable for guys that are running like electronic
transmissions or you're running data act. So you take an old school device, but you've got it set
up to kind of mate with some modern tech. You can. I know you can put O2 sensors on it, but now,
you know, on our fast line, we got this wireless O2 sensor setup that you can have a little display.
So you're playing with your carburetor with your screwdriver, you get the satisfaction of that,
but you're getting kind of modern input. Kind of cheap, a little bit, you don't have to pull plugs.
Yeah, well, the other feature I thought was kind of interesting, which I'm that kind of guy like,
I've always cut the towers off my carburetors, you know, like you don't have an official choke on
it, which to me is totally fine. Right. If I got to, you know, work the throttle for a couple
minutes, whoop-de-doo, you know, I'm making enough, I think I'm making extra power because it's so
smooth up there. Yeah. What's a choke? What real, what real car guy has a choke?
I don't say it. It's a choke order on a carburetor.
Yeah, man. Don't do that. You grind all that nonsense right off. You don't need that stuff.
Exactly. You guys were in my head. Yeah, man.
What does bird want in a carburetor, man? So let's make this. Let's throw some more spice and
sauce in there. All right. Cool. Hey, how was, how was that, that sort of round table meeting
when you guys were designing this? Were there, you know, wild things that you wanted to do that you
realize the industry needed? You said, you know, while we're at it, we could do A, B,
we could do C, we can even make it, you know, we could have an O2 sensor, we could do this.
Like did everybody have input or are you just shot for the moon and accomplished all of it?
It was kind of a shoot for the moon, but it was one guy pushing who said,
I've always wanted to do this. I've always, you know, like, what, what would be the ultimate
carburetor? And he was like, they argued about what not to put in it, you know?
Yeah, exactly. Let's take this out. No, let's not do that. No, let's put it all in there.
Oh, it might cost more to put those baffles in the fuel bowl.
I was going to mention, like, again, you know, I grew up, you know, big drag race fan kind of guy,
but then I got really into road race track day type stuff. And you guys put all kinds of baffling
in the float bowls and more volume, right? So all that sloshing around and uncovering your jets,
like kind of a thing of the past. So yeah, very cool.
Because you think about it with that, with the floats, with the corner cuts, and then the
holes for the extenders, jet extenders coming through and all that, you get,
you're looking at the average now fuel in the bowl, rather than if you have more of a squarish
float, then it's getting tipped off like you were saying, you know, you go into a turn,
all the fuel goes to one side of the carburetor pushes the float up, and you're shutting off
your inlet fuel, where, you know, if you got the chamfer there, it's really looking at the
average amount of fuel in the bowl under any kind of condition, acceleration, deceleration
turns. So yeah, much better. Well, I gotta, I gotta tell you, man,
Willie picked that up down in our studio and brought that carburetor that I think that one,
right, that you're looking at, brought that carburetor on his carry on luggage,
through the TSA. Yeah, right. And they let him like, because we're flying together,
but in separate lines, he's like, bro, I don't want to do with my carburetor. I gotta carry on
bag. I put it out and he's, and the TSA guy was like, what is that? I'm like, that's for a 500
keep against big box, sitting in a 67 barracuda at my house. That's a carburetor, sir. And he's
like a what? And I'm like, carburetor, he act like he never seen one. Oh, man. Yeah, man.
Meanwhile, I had some little screwdriver, something in my bag like, sir, you got stuff
aside. We've got a strip search. It's just checking the cavities in your body.
This guy walks through with this big old slug of carburetor that he could,
I don't know, smash a skull with or something, take over a plane, you know, like,
put that on a plane and fly faster. She could probably knock a window out with this guy.
Hey, hey, Brent, how do people stay in tune with what you guys are doing and these cool
carburetor offerings like we were just talking about. Edelbrock.com website, you know, we've
got videos on there, the connections to those. If you go to our tech center, so those are all
posted. We've got obviously, you know, a YouTube page and we've got Instagram, all that kind of
stuff. But yeah, a lot of it too, which is really fun. It's just people buying one and put it on
like, you know, your car, like a barracuda and then show it to other people. And that's what I
get into. I just think that's the bad part. I can't wait to get my hands on one and put it on
a ride. Do you have anything carbureted? Do you still have anything? I don't right now, man,
because, you know, the craze has been getting over into fuel injection. But, you know, I've been
doing that for so long that it's time to go back around. You know, we didn't even get into it. My
brother runs a dyno shot. We talked to him on the podcast before, but there's a large, there's a vast
amount of people that are putting intakes and carburetors on these LS engines and making just as
much power as a fuel injected version of it and having no issues and problems.
It's definitely cheaper out the go. And in performance, you're not losing any performance
at all. Definitely something to consider if you're out there thinking, man, I got this LS, but I
don't want to mess it up. Fuel injection and computers and blah, blah, blah. I just want to,
I don't want to get in and rip it. Here's a great option for you and that can work,
you know, especially for comfy with a carburetor. So yeah, man, check that out. But you're not just
get comfy, man. There's all kinds of books and stuff online. And man, you can get to be a smart
carb guy pretty quick. It's a fun way to go. I'm ready to go back old school again.
Right? Yeah. And turn the screws. Help you out. Awesome, man. Hey, speaking of helping you out,
make sure you check out our show, Aaron Weekends on Discovery Turbo. There's a way to get some help.
Check your local listings also available on Discovery Plus. Thanks to our producer,
Scoop, senior producer, Justin Carter, executive producer, Bob Ecker. He's Kevin Byrd. I'm going
to be in this is the Two Guys Garage podcast. Yeah, don't forget, check out our website,
Two Guys Garage. We're everywhere on social at Two Guys Garage and the Two Guys Garage podcast.
It's copyright 2026, Britain Productions Incorporated, All Rights Reserved.
Yeah, man, Brent, I'm stoked. I'm going to have this on that car here in about a month.
I got about a project for about a month longer in my shop and then that barracuda is coming over.
I'm putting this thing on it. I'm really excited, man. Way excited.
You know, we didn't get to talk about tunnel rams, but every time we'd be on the damn dyno,
if a tunnel ram came across like a prototype tunnel ram, we had one where we were putting a
throttle body on the front, kind of like a high ram, right? Holley high ram, throttle body in the
front with tunnel ram runners, runners. And okay, it's running okay, but something's a little
weird. Something's a little weird. We put two carburetors on top or two throttle bodies either
way. Freaking 40 horsepower, 40 horsepower, putting two carbs on top of a tunnel ram versus the
front feed throttle body, you know, tunnel ram forever, baby. That's where God intended them to be.
And then you look at some of like the new LS runners, you know, in an LSXR manifold,
it's just a tunnel ram runner kind of folded over so it could fit under a hood.
You just stretch that up and you have a nice straight runner.
But once you took that constraint of here's the carburetor, it's got to go somewhere,
you could take the same designs and repackage it.
Yeah, right. So yeah, exactly. And if we'd gotten more into like the evolution, we would probably
end up with. And y'all forgot a key component, trunk full of cool points, trunk full of cool
points, cool points, cars everywhere. All right, man. Take care. Yeah. Thanks for coming on,
man. We will have to get you back again. I've got to get my hands on one of these carburetors
and hope you guys had some fun with us. We will catch you on the next Two Guys Garage podcast.
Take care. Two Guys Garage podcast is a production of Britain Productions. For more
episodes, visit iHeartRadio, Apple Podcast, Spotify, or wherever you listen to your favorite shows.
About this episode
Carburetors and intake manifolds are still central to performance, and the episode digs into why: matching parts to the right RPM range, shaping runner/plenum pressure waves, and using dual-plane vs single-plane designs to change torque character. The hosts walk through tunnel-ram examples, runner length effects, and intake “signal” from carb barrel staging. Later, they shift to carburetor tech—Edelbrock’s VRS multi-circuit approach, power-valve vacuum enrichment, and modern sensor-assisted tuning—plus practical track-focused fuel-bowl baffling.
Willie got his hands on the new Edelbrock VRS carburetor for his 500-ci big-block ’67 Barracuda project—but first, he had to get it past TSA. In this episode, Kevin and Willie sit down with Edelbrock’s Brent McCarthy to discuss why this 4-circuit masterpiece is a total game-changer for the industry. The conversation goes way beyond the bowl, diving into the high-tech evolution of intake manifolds—from the restrictive “gas crisis” designs of the ’70s to the legendary Performer RPM and Air Gap series.
