H22 honda challenge build questions

[Karl]

do to some changes in the rules I am running in the h1 honda challenge class this coming year, and with that I can do a lot more with the motor to make some power.

in short I am allowed, any Honda part in the for the bottom end, that is any honda piston, rod, or crank. They must be honda parts and max compression is 11.5-1. Current compression is 10.6 so a little off the top wont be enough. Pistons can be notched for valve clearance and any fasteners can be used.

I already have a nice rlz head with springs and retainers, but I can put any camshaft I want in, skunk2pro2, types, webcam, bisi. What would work best in a 11.5 compression motor that I dont want to have to spin to the moon, for reliability reasons.

With the mostly stock h22 as it sits it makes a healty 194 on the rlz dyno. It reads roughly 15% lower than a dynojet.

[Ghetto_CB7]

Yo

For stock parts on bottom end.

If you can get away with 11.6 comp ratio, or run a slightly thicker head gasket.

h22 block
f22a crank
f22a rods
h22a pistons

with a stock head gasket will be 11.64 compression ratio

as for the head, I think I would recommend not using the s2p2, I would use the p1 if going with them. From what I have seen the S2P2 requires higher compression that 11.5.

Are there any limitations to bolt on's and fuel being run, I don't know much about the type of racing this is lol.

EDIT: Also for camshafts, the type s cam is very aggressive, but was not designed for the h22a, and h22a1 head, it is designed to work with the casting for the h22a4 and f20b heads. I don't know much about the bisi cams, I cannot find many people running them, which is sad.

[Karl]

that combo might work, the machine NASA and HC use to measure compression is called a whistler and it seems to read low on the hondas I have seen tested.

On the other hand it might not and I am a regional series director and I dont want to exploit that loophole in the hope that the testing method will be corrected.

How is the head casting different?

[Ghetto_CB7]

not too sure

I am not sure of the exact differences, but I have seen instances of the type s cams eating hh22a/a1 rocker arms.

As for exploiting the rules you can always just run a slightly thicker headset to lower the cr

[Karl]

how much can you drop compression via head gasket and still be safe?

BTW the head already has had a minimal decking truing but that should not have much effect on compression.

thanks for the help so far

[wed3k]

factory is .030" right? if you went with a .050 then the .020 extra should drop you a little less than half a point.

have the rods cut and honed a little more. this should drop the pistons in the hole depending on how much you cut off the cap and rod. this will allow you to deck the block as well to clean up that surface. so say if the machinist cuts .010" total, it will drop the piston .005 into the hole.

[mndude07]

Flat faced valves.

Also, use exotic coatings on the head. That'll help you out alot. This is a road race, so don't use the F22a crank. Keep the stock H22 configuration. That's the kind of racing the H22 was made for and the F crank is only going to hurt top end power and give you torque down lower where you won't need it much.

[The G-Man]

Flat faced valves.

Also, use exotic coatings on the head. That'll help you out alot. This is a road race, so don't use the F22a crank. Keep the stock H22 configuration. That's the kind of racing the H22 was made for and the F crank is only going to hurt top end power and give you torque down lower where you won't need it much.

Yeah but he is going to be running in the lower RPMs as stated. What like 5k-7k?

[wed3k]

Yeah but he is going to be running in the lower RPMs as stated. What like 5k-7k?

lol, 5k isnt low rpm

[PirateMcFred]

EDIT: Also for camshafts, the type s cam is very aggressive, but was not designed for the h22a, and h22a1 head, it is designed to work with the casting for the h22a4 and f20b heads. I don't know much about the bisi cams, I cannot find many people running them, which is sad.

Where did you get that information? Because I disagree. Explain exactly what you think the difference is and why it won't work with the other H22 heads. Why is .469" gross lift and 235˚ duration at .050" intake VTEC lobe "Very aggressive?"

The aluminum head casting has no bearing on rocker wear. The Type-S valvetrain geometry is exactly the same as the other H22 heads. The only difference was the valve seat angle (45˚ vs 60˚). SL and SM rated oils which have less Zinc Phosphate high pressure anti-wear additives to lower emissions in addition to excessive aftermarket spring rates DO contribute to rocker wear.

I've not read any specific cause for rocker H22 wear wear and my experience with Type S cams in an H22A1 head with aftermarket inner valve springs have not caused any issues in thousands of miles.

[mndude07]

Where did you get that information? Because I disagree. Explain exactly what you think is the difference and why it won't work with the other H22 heads. Why is .469" gross lift and 235˚ duration at .050" intake VTEC lobe "Very aggressive?"

Its an OEM cam still, not that aggressive like you said. I think they "eat" rockers up from improper valve lash, not the right valve springs, cam degree is off, etc. The ramp can't possibly be that high.

[Karl]

Valves must be stock, here is the rulebook. Rule #1 if it does not say you can do something than you cant.

http://www.nasaproracing.com/rules/Honda-Challenge.pdf

I want to keep the revs under 8k as much as possible. The f22a1 I was running did fine up to the 7500 limiter and the new h22 still has the limiter at 8500 but I am trying my best to shift around 7750.

[mndude07]

Valves must be stock, here is the rulebook. Rule #1 if it does not say you can do something than you cant.

http://www.nasaproracing.com/rules/Honda-Challenge.pdf

I want to keep the revs under 8k as much as possible. The f22a1 I was running did fine up to the 7500 limiter and the new h22 still has the limiter at 8500 but I am trying my best to shift around 7750.

You'd be fine taking it up that high as long as its healthy. Run Amsoil. That shit's magic.

[Karl]

you have to understand how hard road racing is on the car, drag racers run their car for 15 sec or less in the 1/4 mi run. At lowes motor speedway I am foot to the floor for over a full mile, and the races are often 30-40 minutes long. There are also practice and qualifying sessions.

I will use the higher revs on occasion but I cant rely on them every lap and expect the same life out of the engine. Magic oil or not.

[mndude07]

I really don't think you're going to have an issue if the motor is built well. I have race experience with FSAE, and that car has to run quite a brutal endurance race that many cars don't even finish. RPM's are bad because of the piston accelerations and the resultant forces placed on the rods and bearings, that's what makes motors fail. A higher rod/stroke ratio is going to reduce those forces and make the motor happier at higher rpms. I'd have to do the math, but its a possibility that a H22 crank & rod setup at 1000rpms higher will still have lower piston accleration than a F22 crank & rod setup at 1000rpms lower. Just something to think about. I'm sure you've thought about an oil cooler as well.