Thread: SR22VET SR16VE N1 cams problem

Hi!

We build SR20 RWD engine with 91mm*87mm bore and stroke, P11 primera VE head, SR16VE N1 camshafts, supertech bigger valves, BC valves springs and titanium retainers, T4 Divided 1.06A/R GTX3076R turbo, twin scroll big tubular manifold. CR around 9.0:1

The car is now spool very good, very good mid power. Now just 14psi the boost.

The problem is, that sometimes the valve shims go out from retainer. I cant determined, when it is happen. Sometime I go to two day drift competition, and work fine, sometimes I go to the street, and after one 2rd gear pull go out.

I dont was on dyno, but I feel, and seems from fuel map, that after 7300RPM power fall down stongly. The fuel and timing maps is correct, I think problem with camshaft timing.

We tryed some camshaft dialing, when the overlap was 0, the car power was very bad, best power I feelt, when the intake and exhaust valve was the closest to the piston at TDC.

Maybe somebody have cam gear dial tips for this setup?

I would say u might have to reshim ur head if the keep popping off. Now is it usually the same one that keeps popping of or different ones. Also @Payu might be able to give u some hints on cam timing

Did you re-shim the head after assembly? I would check the valve lash for the shim problem. You could also switch to the mazworx shim less head setup. As for the cams there are only a few people running n1's with a turbo setup since it has so much over lap. The few people I know that are running them run them straight up.

Yes. all valve clearence was set correctly. I dont find any information from this shimless head. This is common problem, to loose the shims?

Yes, this a common problem if you constantly in very rpm
with boost. I had this problem many times then I switched to the shimless setup.

This is what it looks like.

I'm a little happy, to hear, not we was fool, that it happend few times, but sad to know, that VVL hav problem with high rev too.
Before my DET head usually brokened the rocker arms when the rev limiter or launch control was hard.
My rev limit was just 8000RPM with this VVL head.

This kind of shimless conversion dont like for me. Cant adjust, and once, when I loosed the shim, the rocker arm damaged the valve.

If I machine new retainer, and new shims, which look like RB or CA shims, which fit into top of valve, I think the problem will solve. But it is high cost way.

I dont get why people are having issues with shims popping out. Id say the head wasnt shimmed right more than anything. My stock valve head, shims all put back in their original places. No valve work done, clearances all measured out within specs had no issues with n1's revving all the way to 10,200 at one point pounding off the rev limiter down the track. Never popped a shim out.

Are you using aftermarket springs and retainers? Im using the supertech 130 lb seat pressure springs and titanium retainers on mine. That is the only valve train work done.

I think you really need to look at how the valves are shimmed and make sure they are within specs.

I had my n1's set to 0,0 as far as cam timing goes. Made peak power all the way to 10,200. But much larger turbo than the 30r. Might want to either go with a larger turbine housing especially since its a big 2.2L motor. Need more exhaust flow id imagine. Better flowing manifold and turbine side the better the n1's will work.

The shimless setup is the ultimate way to go, you really wont have to worry about adjusting valve lash for a while. The valves are specifically designed to take the abuse and resist wear with the hardened tips/tops. Once they are set you shouldnt have to worry about it for a long time.

But still, I dont see why people would have issues popping out shims if everything was set correctly. Ive never seen a ve pop out shims.

Only ones i can recall are ones with aftermarket valves that have had valve work done, stock heads ive yet to see one get thrown if everything is put back into place where it came from and everything checks out valve lash wise. valve lash is the only thing i can think of that would keep causing that.

The valve clearence set correctly to factory specs. I can find it again, but I remember exactly, that intake around 0.2mm exhaust around 0.3mm.

First I buyed Supertech 100lbs spring, but the retainers damaged after 1race.

After I buyed Brian Crower set.

I use the car for drift, so much bigger turbo I dont want to use. Maybe I will try with GTX3582R 1.06A/R T4 divided. That is my goal.

But now I still cant rise boost, and RPM, because I fear from shim pop out.

Serius, that you never was issues. Why many people have same problem, others not?