Car has ARE Stage II heads, Comp Cam 232/236 .595/.601 @ 112 and double springs that ARE put on when they did the top end package, so I'm not sure which ones they are.


About 3 months ago, I was out having fun, and a strange noise starts. Determined to be a fault lifter after examining valve train, etc. Changed to comp -r lifters. About 1.5 weeks after that, another failed lifter! So I then change to regular comp lifters. I have driven for about 2-3 weeks. I went to race today, did burnout and in middle of burnout, a lifter collapses!

I was not able to ever determine what cylinder had the faulty lifters from before. This time, it is # 1.

One more note that may or may not be relevant...When I pulled valve covers to diagnose the 1st time, the valve seats were completely trashed and shredded. There were metal slivers and debris laying on the head. ARE gladly cleaned up the heads, and corrected the seats.

What is going on here? This has to be an oil pressure issue doesn't it?

My 2 theories.

The motor has a blocked oil passage somehow, possibly from the metal debris? But doesn't the oil that feeds the lifters come from the filter? Is there any way metal could have gotten into a passage?

or

The car is an 01. I was assured by the owner I bought it from that it did not have any oil consumption issues. This has not been the case, and I did have a low oil light come on 2 times, which I promptly fixed.

Not sure where to go. I have zero confidence in just replacing the lifter(s) again. There must be something causing this. I am wondering if I'll need to pull the motor.

TIA

 

One way to tell if you have any blocked oil passage ways is to turn the car over with the valve covers off. If oil comes out of the purshrods and over the rockers I doubt it is blocked. One thing I would check into is valvetrain geometry. Maybe yours is so far off that you are putting a shitload of stress on some of the parts? I could be completely off base here but its something that I am thinking.

 

Had same problem here. Car is at TTP right now getting a new block. They told me the same thing you are thinking, oiling problem or some type of bearing problem. They didnt want to take any more chances hence the new block. Broke a lifter 3 times on different cyclinders each time, and when they went they also scored up the cam so that was replaced also . New forged LS6 block with forged internals going in.

 

ttt anyone else?

 

Have you checked to ensure you are using the correct length of pushrod? There is something going on here. I doubt it is bearings but I think it may have more to do with your pushrods being too long perhaps putting too much preload on the lifter when you torque down the rockers. How much has been shaved off the heads? Hope it all works out.

 

My first impression was an oiling problem too. If you pull it all apart and it still is usable, you could always have a machine shop freshen it up and clean it rather than replace everything. When I blow up my bottom end I am going for a reliable 6.0 liter short block. Sweet. Who cares if it weighs a little more...just remove the AC!

 

 

What preload are you running?Too much or too little can trash lifters.

Also if the there is too much spring pressure it will trash the lifters.

 

How much more do the 6L blocks weigh than the 5.7's?

I am not sure how much preload I had. I am not sure that is it, I had never had the valve covers off when the first lifter failed. I believe the motor was last touched by ARE, and they know what they are doing.

Anyone know of a motor remove/install write up for a vette?

 

We'd need to know:
-springs you are running
-spring pressure
-which lifters
-what preload you are shooting for

If that all checks out you have an oiling problem.

I have had 2 sets of Comp R's and they work great.

 

springs = don't know exactly, trying to find out from A.R.E. They did top end package, and used doubles with the stock lifters. I would assume the spring pressure was ok to use with the stock GM lifters. If not, the the comp-r's should have been able to handle.

spring pressure = see above. the heads were recently freshened up by A.R.E. and they made sure spring pressure was ok. Again, I do not have numbers.

lifters = 1st go, stock. 2nd go, comp-r (875), 3rd go comp (850)

dont know what preload was with stock lifters, i never had valve covers off (no need to). preload was ~ .030 for comp-r's (~1/4 to 1/2 turn to torque to 22 lbs). preload was ~.030-.045 for comp (850's).

I did notice my oil pressure was ~ 10 psi at idle after a long trip. I am not sure if that is too low?

 

I'm afraid I'm having the same problem. I've been dealing w/ a high RPM drop in power for a while and last week it started ticking. I'll be pulling it soon.

 

Comp reccomends .002-.010 preload for Comp R's but I don't know that .030 would be a huge problem. Really we have to know what springs you have too.

 

I've had lose of power in the higher rpm also. I feels fine at low rmp's but when I get into it, it seems to get a little sluggish. I also get a differnt noise at the higher rpm's it just sounds sick....

 

PSJ, I'll try to find out. ARE told me to set preload at .030.

ARE is not answering their phones today. Must be a canadian holiday!

 

did anyone else notice this???

 

Maybe I'll put a solid lifter cam in the car. Piston to valve clearance may become an issue, however.

 

Damn good catch. That oil pressure is really shitty at idle. Mine is close to 40 at idle.

Also I have had some problems with the comp r's and the yella terras. I first had valve float and after shimming and pushrod length change the float went away. Then about 1 month later 1 of the lifters actually had an indentation on it. It was not chipped away but actually looked as though it was smashed lol.
Put a set of stockers back in due to all the problems. It might be a good idea for you as well. Seems like Comp Cams quantity control on the comp r's is not really that good.

 

I had regular comps in the 3rd time, the 850's.

So 10 psi is lower than everyone else, it seemed low as hell to me. But I haven't really payed much attn to it before, or other peoples.

 

I dont really feel like replacing the lifters until I figure out why they are failing, I'm scared one will fail again.