In this episode of Racing Insiders Podcast, Kate and Steve discuss carbs, regulators, and push, push, pull. They also discuss Kate's last minute trip to Charleston, radiators, racing promoters and their behavior, words Steve cannot say on the podcast, evac kits, aviation fuel, and fans.

Would you rather run the valves on a 602 with the engine hot or cold? (6:17)

Well honestly, either way works. I mean, so long as you can feel where zero is. Then you can do it hot or cold. Where you can feel zero, when you're actually on the overlap - the way we recommend setting the valves. But let's just pretend that a person doesn't know anything about setting their vows, what does it feel like to be at zero? When you're when you're adjusting the the poly lock or the nut, you go to where you get to zero. So in other words, the rockers got lash, and then you're turning it with your index finger and your thumb. And when you've got no lash, that's zero. Then what we do is go three quarters of a turn, preload, and then I'll back off about an eighth of a turn, tighten the center adjuster screw and come back up that, that eighth of a turn, and that locks everything in place.

I have a triple pass radiator in my SPC Sprite, it runs hot with an electric water pump. Ideas? No thermostat. (8:18)

Get rid of the triple pass. Unless you're running some sort of car that's going 150 miles an hour on asphalt. I've never seen a triple pass radiator successfully cool anything. Rule of thumb, and I wish that Art was watching and would comment on this. But rule of thumb because we've had this conversation, it may be a little bit different than what I'm explaining it as is generally like when you go from a single pass radiator to a double pass, you slow the water down by roughly 33%. When you go from a double to a triple, you're slowing it down another 33% in the system. So now you've got water traveling 66% slower in the system, roughly, than what you would with a single pass radiator. And because of that, it slows it down so much that you basically make it to where the water just super heats in the engine. So unless you've got ram air going through that radiator, like literally like 150 mph ram air, then that's not going to work. And if you don't have that, then no you're completely screwed. And that being said, once you've got slowed down that much, the only way to solve that issue is you have to increase the flow by that much, roughly. there's actually a really good video on our channel on Crate Insider. And it's me talking to Ben Baker from AFCO and we talk about that the single double or triple pass radiators and that's also a very good explanation.

What is the best carb for a 602?(14:05)

That's a loaded question. I like to know what your rules are, what kind of fuel you're running. I mean, I've always got several suggestions as far as that goes. I mean, we build our own. So that's one of my preferences. You know, David Smith, Willy's - just depending on what your rules are, what kind of fuel you're using, like, that sort of thing. I mean, I've recently heard- did Stealth sell? That's what I heard. That's what I heard from a racer. Yeah, I'm not I'm not 100% sure on that. I've heard that he sold the business, but you know, I don't want to start a rumor.

Any advantage with a 411-rear end versus a 486? In a 604 dirt late model? And what lubricant do you recommend for heim ends? (18:06)

Yes. So if I was in any sort of limited horsepower application, I would 100% be on a 411. It gives you a smaller ring and pinion. Testing it back-to-back. I'm wanting to say I mean, and again, this is so many so long ago when we did this. I'm wanting to say there was about a 1% acceleration gain in the 411 versus the 486. So, that means everything. Especially when you're in a limited horsepower application. Let's say that it's a zero to 60 or zero to 100. You're getting a 1% gain. One to one and a half percent. For lubricants, we recommend Daytona 1 Spray Lube or switch to PTFE FK Rod Ends. And that way, you don't have to grease them at all. And if you don't have to grease them, then they don't gather dust. And, and they're really self-contained. And they last you for forever.

How often should your car but be torn down and gone through running a 602? On 85 with a stealth carb? (20:42)

Yeah. So, I mean, honestly, if you're racing week to week, you know, normal maintenance on the carb is going to be, number one, don't touch anything - if it's running, right. Throttle shafts are going to be the thing. So, you want to lube those as much as possible, with like penetrating oil with the engine running. So, it sucks it into the throttle shafts because there's bushings in there and stuff that need to be lubed. Other than that, once a year, maybe. It's kind of an end of the season thing. I know when I've talked to Willy about this, you know, just like many of these components, you want to get them you know, like freshened. You want to use a little bit of grease on the pump cams. Accelerator pump cams, which we normally use DayLube on our stuff. So, you want to do that. Because obviously you're washing the race car. So it's going to blow all that out of there. I would use a little bit of DayLube between the pump cam and the pump arm. And then probably have it serviced once a year, especially with the E85.

I mean, at the end of the season, send it back to your carb guy, let him go through it. You get it back. It's fresh. It's clean. 

Can you run the evac kit with anti reversion mufflers, or is there too much back pressure? (20:23)

Yeah, you can absolutely run it. That means said, I'm not a huge fan of the evac kit. Because the seals on the engine, if we're talking a crate engine, are not actually designed to prevent dirt from being pulled evac into the engine, basically. So, if you're pulling a vacuum in the engine, that means you're sucking whatever is outside those seals into the engine. So, it's not something that is designed to do that. Does the evac system work? Yes, it does. 100% it works, old technology, but it works. But you just need to be aware that you're actually second stuff in the motor, potentially. But you know, I think when we're looking at this too, so the evac units, they're not legal in really any of our eastern classes - east of the Mississippi. But you get to the Midwest, and they are and a lot of those guys have to run chips that are that are not as like we run much higher chips on this side. So I mean, I've had customers get the evac kits, and I mean, they're perfectly happy. I at least I think they are. I usually know when they're not. When people aren't happy, they let me know. A lot of places out there. They're not allowed to rebuild the engine, right. So, they never they never see the engine bearings at the end of the season is what I'm getting at. Yeah. Right when you’re sucking dirt in the motor and it's going through the bearings, it looks like shit at the end season. 

602 crate with a Holley 654 barrel. What is your first choice for a carburetor spacer? (32:59)

Yeah, that's going to be that HVH spacer. It's going to be the one where we call it the one with the dual plane intake manifold. Yeah, to carve space out of everything I've tested that when actually makes the most power. And I've got them on the way. So it's just got little center dividers, like rounded off. If you look at it, and you go like, Oh, my God, this makes power? Well, it does. Yeah, part of the reason that it does is because the profile of the carb spacer matches the profile of the intake manifold. That's the biggest, biggest reason. So rather than just being an open spacer, what you're able to do with that center divider is to really direct that fuel properly into the into the intake manifold and then of course, into the cylinder. 

Is it hard on motors going back and forth from 85 for one series than gas series rules for other races? Probably be about once a month type of a scenario. (36:05)

No, it's not. No, no. It's not at all. Years and years and years ago, we used to go back and forth between gas and methanol. So if anything's gonna be rough on anything, it's gonna be gas and methanol. 

What's your opinion on maximum timing in hot weather? (41:33)

There is a variable. So like, let's go with a 602. For instance, if you're running, if you're on the 85, run on a 602. I don't care what the weather's like, then generally, you know, you're safe at 36. If you're on race gas, and or pump gas, let's let's say pump gas on a 602 in that same scenario, then you know, you don't want to be over 34. Because detonation will occur. And a lot of this is going to depend again on the humidity. It's going to be the air density, all that stuff.

What do you guys think the best rocker arm is? I've tried all kinds, but looking for the best? (43:32)

602/604- I mean, the factory stuff. So, the stuff made for GM like on the 604 is gonna be a Scorpion rocker, which is great rocker. I mean, it's the rocker I've got right now. They're really awesome. If we're like talking open engine- T&D or Jessel.

I know many guys in the area running aviation fuel. Can you help me explain why not to run it other than it's for an airplane not a racecar? (45:58)

This has been one of the most divisive items that we've ever put onto YouTube. And there are people who- their love for Avgas is is that a whole other level. So that anything other than altitude, it makes no power. I mean, just just to sum it up. it's a really, really dry fuel is what you found. And then you know, the argument that gets pushed back on you, Steve is like, "airplanes are at sea level when they take off and they've got to have some power for that". Well, you're an idiot. Because you don't know anything. They have wings, and they have lift. Racecars don't have wings or lift. So we're not we're not racing airplanes on the ground at a dirt track. We're racing cars.

Honestly, when Avgas actually took off as a thing. Because the gas in the United States starting turned unleaded. Yeah, as gas was still leaded. So that's why everybody was all about Avgas back in the day was because as we went unleaded, I believe it was 73-74, 75 Somewhere around there when we went unleaded gas was to let it because, you know, Valve seats and everything else and airplanes were they had to have leaded fuel. And yeah, in order to lubricate the valve seats, cars did not. Well, they did, but then that's when they invented hardened valve seats for cars. But Avgas never went away from I mean, because you got you still got planes today like once every few seconds that are like like 1972. Literally, 72 once every Tues flying around today on Avgas, which is leaded. And, you know, because of all the crap that we had back in the day, getting rid of leaded fuel. That's what you ended up with as far as racecars go. Because you can take like a set of 1968 cylinder heads, run that crap on pump gas today without destroying the valve seats.

What lower octane fuel helps vapor lock the most? (54:02)

Well, I mean, I mean, no, I mean, vapor lock can occur no matter what you're using. I mean, I've had vapor lock with methanol. So I mean, vapor lock is going to cure no matter what you're using. get the heat source out of the fuel. So I mean, bypass regulator. I mean, the first thing, any kind of fuel system you want to be bypassing fuel, because that keeps the fuel in constant motion which actually cools it down. So regardless. But there's no magic cure to vapor lock other than get the heat source out of the fuel.

Let's explain bypass regulator for anyone who might be running like a deadhead regulator. With a bypass regulator, you are taking the excess fuel that your engine doesn't need that excess fuel, rather than being backed up through the system, which is through it, which is what a deadhead would do. How Willie described it to me is then if you've got a deadhead regulator, and it's just holding the fuel back, then your fuel pump becomes a fuel heater correct. So another way to do this would be a bypass regulator, and how that would work is that is also connected to the fuel and to the fuel line. And whatever fuel your engine doesn't need. At that time, all that excess fuel is taken via a line and put back into your fuel tank. Now your fuel tank is always going to be basically at room temperature. And if you think about it, like taking a hot cup of coffee, and like dumping it into a pool, it's not going to change the pool water, you know, so you're you're keeping that fuel in your fuel tank, as cool as it possibly can be, you know, your subject to room temperature. But what you don't have superheated fuel that is going through your system that's gonna vapor lock. Yeah. So that's, that's my explanation for the advantages of running a bypass regulator. I mean, that's the reason to run one. And I recommend that on no matter what you're using, but that also requires a high pressure pump. In order to make that system work. I wouldn't say high but higher. So you know, like your standard fuel pump. There we be running a deadhead regulator, like we've got the pro cam, the seven and a half psi, and then this you would change to a 15 psi. If you change one thing, you need the other in order to be able to push that amount of fuel through this.

Why am I going through so much fuel with my Super Bowl? Alcohol, a one jets one click to lean on 604? (57:27)

That would be a great question for Willy. Yeah, it really wouldn't be but like by going through so much fuel? Are we talking about like warming the engine up? Are we talking about racing? I mean, because you know, methanol burns at roughly 2.2 times the volume of liquid. So you're gonna burn 2.2 times more than let's say pumped gas or race gas. So you got to be able to expect that. I mean, if anything we've discovered with the 85 is is the amount of fuel you guys are going through just to get the engine up to temperature. Right. So the solution that we found for that is to run the arts thermostat. Because what it'll do is it'll recirculate the water until it gets to the right temperature. And your car's warmed up and you go through a whole lot less fuel. So generally, like dealing with what we deal with is, we can't use methanol here. Which I wish we could because I love methanol, but because we can't we E85 is our option.  And generally we burn more fuel warming the engine up like you were just talking about, then we would actually racing. But this is definitely a question for Willy.

Is the 2 Blade Fan pushing or pulling air? (1:00:21)

It's pulling air. It's pulling - if you turn it the right direction.