.020" preload on Comp "R"s?
Thread Starter
Joined: Oct 2002
Posts: 1,413
Likes: 1
From: Lee's Summit, MO (KC)
.020" preload on Comp "R"s? (Oil pump problem??) I have been fighting a valvetrain noise on a 02 TA that has a 402 with ported 6.0 heads, stock rockers, and Comp "R" lifters.
I just measured the preload and I got .020 with a 7.400 pushrod.
I think I remember reading that the 'R' lifters don't want much preload at all, but is this too little? If so, what pushrod would you recommend?
Thanks for your help!
I just measured the preload and I got .020 with a 7.400 pushrod.
I think I remember reading that the 'R' lifters don't want much preload at all, but is this too little? If so, what pushrod would you recommend?
Thanks for your help!
Last edited by Ponyhntr; Mar 28, 2008 at 09:34 PM.
Thread Starter
Joined: Oct 2002
Posts: 1,413
Likes: 1
From: Lee's Summit, MO (KC)
i believe the recomended preoad is .002-.004 on a warm engine and adjustable rockers are suggested also. i used them once before and i set them at .010 on a cold motor with adjustable h.s. rockers.
X2..
Something about the .020 threw a flag in my head. Try .050 Pre-load and see where it takes you.. ADJ rocker may be soon in your future.. easier on the wallet in the long run.. Just a couple of minute adjustments instead of waiting for new PR's.
Something about the .020 threw a flag in my head. Try .050 Pre-load and see where it takes you.. ADJ rocker may be soon in your future.. easier on the wallet in the long run.. Just a couple of minute adjustments instead of waiting for new PR's.
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I never use those lifters. Do like we talked and if the noise goes away, you know what to do then. 
Thread Starter
Joined: Oct 2002
Posts: 1,413
Likes: 1
From: Lee's Summit, MO (KC)
OK, after talking to my source at Comp, he said that the optimum preload on 'R' series lifters was .004-.010" of preload. Since there was basically no way to get there without adjustable rockers, I decided to put a set of LS7's in the motor. Guess what? The noise is still there! 
I didn't get a chance to check the preload, but the only thing I changed was the lifters.
Could this be a oil pump problem after all? The noise is not there at idle. It only becomes apparent after cruising down the road a mile or two. It is definitely RPM-related, and after sitting and idleing for a minute or so the noise will go back away until driven again.
It's got a stock 2002 LS1 oil pump in it. With fresh 5/30 mobil 1 it has about 45 psi of pressure on the gauge when hot. The oil level while ticking is full.
I can't figure this damn thing out!
Thanks in advance for any advice!
I didn't get a chance to check the preload, but the only thing I changed was the lifters.
Could this be a oil pump problem after all? The noise is not there at idle. It only becomes apparent after cruising down the road a mile or two. It is definitely RPM-related, and after sitting and idleing for a minute or so the noise will go back away until driven again.
It's got a stock 2002 LS1 oil pump in it. With fresh 5/30 mobil 1 it has about 45 psi of pressure on the gauge when hot. The oil level while ticking is full.
I can't figure this damn thing out!
Thanks in advance for any advice!
How did you install them. Did you measure with an adjustable, if not you need to do this to ensure the correct preload. Too little preload will be noisier. If you want to verify the preload, measure for the required length.
OK, after talking to my source at Comp, he said that the optimum preload on 'R' series lifters was .004-.010" of preload. Since there was basically no way to get there without adjustable rockers, I decided to put a set of LS7's in the motor. Guess what? The noise is still there!
I didn't get a chance to check the preload, but the only thing I changed was the lifters.
Could this be a oil pump problem after all? The noise is not there at idle. It only becomes apparent after cruising down the road a mile or two. It is definitely RPM-related, and after sitting and idleing for a minute or so the noise will go back away until driven again.
It's got a stock 2002 LS1 oil pump in it. With fresh 5/30 mobil 1 it has about 45 psi of pressure on the gauge when hot. The oil level while ticking is full.
I can't figure this damn thing out!
Thanks in advance for any advice!
I didn't get a chance to check the preload, but the only thing I changed was the lifters.
Could this be a oil pump problem after all? The noise is not there at idle. It only becomes apparent after cruising down the road a mile or two. It is definitely RPM-related, and after sitting and idleing for a minute or so the noise will go back away until driven again.
It's got a stock 2002 LS1 oil pump in it. With fresh 5/30 mobil 1 it has about 45 psi of pressure on the gauge when hot. The oil level while ticking is full.
I can't figure this damn thing out!
Thanks in advance for any advice!
Thread Starter
Joined: Oct 2002
Posts: 1,413
Likes: 1
From: Lee's Summit, MO (KC)
Here's an update for you guys...
I finally got a chance to check the preload with the LS7 lifters and the 7.400 pushrods. I now have right at .050" preload, which is about right, correct?
I'm starting to REALLY DISLIKE this car!
I finally got a chance to check the preload with the LS7 lifters and the 7.400 pushrods. I now have right at .050" preload, which is about right, correct?
I'm starting to REALLY DISLIKE this car!
You want 0.080" - 0.100" if you want it quieter. Sounds like 7.450" would do it.
