BB 454 Valve Train
Thread Starter
Drifting
Joined: Jan 2002
Posts: 1,645
Likes: 11
From: Schaumburg IL
BB 454 Valve Train
I have a 454 that has never been "quiet" with the lifters inspite of a complete rebuild and more adjustments that I care to remember. It seems the passenger set of rockers for #2 and the exhaust on #7 seems to be prone to clacking most after adjustments. [I] also had the lifter on #7 exhaust wear out after maybe 100 miles with cupped wear. I have tried new stamped steel rockers and a set of Summit roller rockers 1.7:1. The roller rockers were a disaster with more clacking that you could handle.
I have adjusted both EO - adj intake and intake close - adjust exhaust, and the Lars method of TDC rotate etc and adjust. The only common item is spin the pushrod till resistance and adjust 1/2 turn.
Either I have a common problem in the valve train or am doing something wrong. Appreciate the comments.
I have adjusted both EO - adj intake and intake close - adjust exhaust, and the Lars method of TDC rotate etc and adjust. The only common item is spin the pushrod till resistance and adjust 1/2 turn.
Either I have a common problem in the valve train or am doing something wrong. Appreciate the comments.
Drifting
Joined: Aug 2005
Posts: 1,682
Likes: 3
From: League City TX
Maybe you just had a bad set of lifters. There are some that just always make noise.
I have heard of others that are noisy with anything less than a full turn worth of preload, which doesnt even make sense.
Also, some of the fast ramp cams seem impossible get quiet no matter how you adjust the preload.
What kind of cam & lifters are you running?
I have heard of others that are noisy with anything less than a full turn worth of preload, which doesnt even make sense.
Also, some of the fast ramp cams seem impossible get quiet no matter how you adjust the preload.
What kind of cam & lifters are you running?
Thread Starter
Drifting
Joined: Jan 2002
Posts: 1,645
Likes: 11
From: Schaumburg IL
I have a set of comp cam lifters, the cam is a Crane 272 which 218/218 and .510 lift. Nothing radical. The push rods are comp cams same with the springs which were spec'ed for the cam. think I will adjust one more time and go for the 1 turn and see how it runs. thx
Race Director
Joined: Sep 1999
Posts: 11,358
Likes: 379
From: Plano TX
I'd do:
1 One cylinder at a time (rotate crank 90 dgr to next cyl).
2 Loosen nut until rocker wiggles up/down. I do NOT like the "spin the pushrod" method.
3 Tighten nut until rocker will not wiggle up/down
4 Tighten a further 1 full turn. This is factory spec.
If it still makes noise after that something else is wrong.
1 One cylinder at a time (rotate crank 90 dgr to next cyl).
2 Loosen nut until rocker wiggles up/down. I do NOT like the "spin the pushrod" method.
3 Tighten nut until rocker will not wiggle up/down
4 Tighten a further 1 full turn. This is factory spec.
If it still makes noise after that something else is wrong.
Le Mans Master
Joined: Oct 2006
Posts: 7,123
Likes: 433
From: Gladstone MO
C3 of Year Finalist (appearance mods) 2019
From your description, I'll assume a hydraulic cam.
I still like doing the initial adjustment per the manual, then the final adjustment with it running. Messy, but never had any excess noise.
I still like doing the initial adjustment per the manual, then the final adjustment with it running. Messy, but never had any excess noise.
Pro
Joined: Apr 2006
Posts: 733
Likes: 1
From: Coquitlam British Columbia
Check out my post #16 in the following thread on the Comp cams lifters, this may or may not be your trouble. 
http://forums.corvetteforum.com/c3-t...post1575899778
ikwhite
http://forums.corvetteforum.com/c3-t...post1575899778
ikwhite
