3rd time is the charm
Thread Starter
Heel & Toe
Joined: Dec 2008
Posts: 18
Likes: 0
From: Altus OK
3rd time is the charm
Car 87 with 128 heads stock cam
So I installed Self aligning 1.6 RR. At 5000 RPM it is making a rattling noise. I had not removed the guide plates because it appeared that there would be no clearance issues. After reading other post I decide it was the GP making the noise so off come the valve covers again and out come the GP's there was no abnormal wear and pushrods were perfect. Reassemble and still making the noise. Now I'm going to do the springs and valve seals and this better be the last damn time I have to take this crap apart. I've decided to go with Comp 981 springs. A Few ? what valve locks do I need there are a lot of different kinds and I cant find the answer in my manuals. Just a part # from Summit would be good. Also could use some good instructions/ advice from those that have removed the exhaust rotators and installed shims. Some shim part #s would also be helpful. I noticed in the manual the exhaust and intake installed spring height are different. That sound right? Thanks.
So I installed Self aligning 1.6 RR. At 5000 RPM it is making a rattling noise. I had not removed the guide plates because it appeared that there would be no clearance issues. After reading other post I decide it was the GP making the noise so off come the valve covers again and out come the GP's there was no abnormal wear and pushrods were perfect. Reassemble and still making the noise. Now I'm going to do the springs and valve seals and this better be the last damn time I have to take this crap apart. I've decided to go with Comp 981 springs. A Few ? what valve locks do I need there are a lot of different kinds and I cant find the answer in my manuals. Just a part # from Summit would be good. Also could use some good instructions/ advice from those that have removed the exhaust rotators and installed shims. Some shim part #s would also be helpful. I noticed in the manual the exhaust and intake installed spring height are different. That sound right? Thanks.
Le Mans Master
Joined: Mar 2004
Posts: 5,107
Likes: 171
From: Dublin CA
Did you look at the underside of your valve covers? Could the springs you have on be so weak for your lift that when you are hitting 5000 RPM they are letting the RR go higher than normal? Check for marks on the inside of the cover. It would more than likely be the exhaust valves since they normally have a higher lift than the intake.
Team Owner
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
It's likely that you need to grind down the drip tabs a bit and narrow the VC bolt bosses.
The 981s will work well, use the OEM retainers with new keepers. Also, install new OEM valve seals.
The 981s will work well, use the OEM retainers with new keepers. Also, install new OEM valve seals.
Team Owner
Joined: Jan 2003
Posts: 20,306
Likes: 242
From: Summerland B.C. Canada
Do you remember this post, from your other thread. 
http://forums.corvetteforum.com/1573141111-post6.html
You cannot use SA rockers with hardened guide plates.
http://forums.corvetteforum.com/1573141111-post6.html
You cannot use SA rockers with hardened guide plates.
