2ZZ worn cam issues

cobra · Mar 2, 2011

I am using my car for track racing and it works hard. The engine has been going for 4 years and we refresh it roughly every 18 months, and it was flawless over this time. Last year Gavin Cronje (Le Mans Series champion) tested the car for a magazine (see this link http://spyderchat.com/forums/showth...s/showthread.php?42355-MR2-2zz-tested-on-track-for-magazine&p=708571#post708571), and he dropped a valve. I fixed the problem by replacing only the one valve, and dropped a valve the week thereafter at Kyalami race track.

I then decided to replace the valves with MWR aftermarket parts, being the following:
Valves http://www.monkeywrenchracing.com/product_info.php?cPath=21_37&products_id=126

Springs http://www.monkeywrenchracing.com/product_info.php?cPath=21_37&products_id=128

Retainers http://www.monkeywrenchracing.com/product_info.php?cPath=21_37&products_id=935

Since then the valves lasted, but I experienced a gradual drop in power. We stripped the head today and found the problem, being wear on the cam and the lifters. See pics

Any idea why this happened?

The wear is on 2 of the high lift lobes on the intake cam only. It is on the "back" of the lobe, being after it did total lift and starts closing the valve.

Could it be that the springs are too stiff?

The cams are OE cams

LittleRocket · Mar 2, 2011

Valve lash may be too tight. I had to move mine to .010 on the intake side after eating 3 cams back in 03.

dev · Mar 2, 2011

I was planing to adjust my valves on the my Honda and I have read that it was a good idea to be on the looser side of the tolerance.

cool_apple · Mar 2, 2011

Burn 2 intake cams/rocker lifter & had in one instance the lifter broke into pieces

cobra · Mar 2, 2011

Are you guys sure valve lash is the only thing which could cause this or should I check something else as well?

I plan to install a Piper cam stage 2 with this setup - should I consider anything else in this process?

LittleRocket · Mar 2, 2011

I killed 3 stock cams with my ferrea valve train figuring it out....

FWIW I would go with the stage 3 cams. The stage 2s make more power with a stock intake. The intake is limiting the head. With your itbs the stage 3 will make the most powah. PS you have pm.

cobra · Mar 2, 2011

Thanks LR!

Cap Weir · Mar 2, 2011

Wasn't there a threead about checking the Aiming and flow of the Cam Oilers?.. As I remember the Factory 'Aiming' of the Oilers was in Question. That was the Subject of the Thread..

Cap

dev · Mar 3, 2011

Yes I remember reading about that on the Lotus forum. It is suspected that the later 2zz which are found in the lotus had this defect.

Osm328 · Mar 5, 2011

LR,
You use .010"/Int & .016"/Exh for Piper 3 cams, but do you do anything different with stock cams? Factory spec is of course .0031"-.0071/Int & .0087"-.0126"/Exh. Just wondering how you lash your valvetrains when you do your swaps with stock heads.

cobra · Mar 5, 2011

Interesting post! I am keen to know the settings for Piper 3 plus the valvetrain as indicated in my first post.

2ZZ worn cam issues

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