Lifter Adjustment Problems
Thread Starter
Drifting
Joined: Jan 2002
Posts: 1,645
Likes: 11
From: Schaumburg IL
Lifter Adjustment Problems
I am not looking for advice on how to adjust lifters, but new ideas on why there are several that just seem to be noisy. This is a BB engine.
I have tried the EO-IC methods, followed Lars papers and still end up with some of them clacking.
I replaced the lifters, replaced the pushrods with stock length, replaced the rockers with new GM performance stock ratio and still have some clacking.
I tried roller rockers from Summit and wow they just did not work at all, clacking and hitting.
Any ideas of what I am chasing are appreciated. If the general concenus is I am adjusting wrong, that's ok and I will try one more time.
Oh - what is the norm for after zero lash 1/2 or 3/4's of a turn. I have been using 1/2, maybe there is some slop left and 3/4 would be better.
Thanks for any comments.
I have tried the EO-IC methods, followed Lars papers and still end up with some of them clacking.
I replaced the lifters, replaced the pushrods with stock length, replaced the rockers with new GM performance stock ratio and still have some clacking.
I tried roller rockers from Summit and wow they just did not work at all, clacking and hitting.
Any ideas of what I am chasing are appreciated. If the general concenus is I am adjusting wrong, that's ok and I will try one more time.
Oh - what is the norm for after zero lash 1/2 or 3/4's of a turn. I have been using 1/2, maybe there is some slop left and 3/4 would be better.
Thanks for any comments.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,112
From: Crossville TN
Hydraulic lifters, I assume....
Are you certain that you are finding the zero lash point correctly? There is confusion about what it means when the pushrod "ceases to spin". If using that method, the intent is that you actually spin and release the pushrod. If it continues to turn, you have not reached 'zero lash' point; if it stops when you release it, you have reached the 'zero lash' point.
I prefer to shake the pushrod up and down. With that method, you can feel the slack in the system without releasing the rod. When the slack disappears, you are at 'zero lash'.
As far as how much of a [CW] turn to make after reaching zero lash point, GM suggests 1 full turn. Many engine guys say 1/2 turn is correct. I have always used 3/4 turn with no bad results. The intent is to find the center of travel of the piston in the lifter.
Are you certain that you are finding the zero lash point correctly? There is confusion about what it means when the pushrod "ceases to spin". If using that method, the intent is that you actually spin and release the pushrod. If it continues to turn, you have not reached 'zero lash' point; if it stops when you release it, you have reached the 'zero lash' point.
I prefer to shake the pushrod up and down. With that method, you can feel the slack in the system without releasing the rod. When the slack disappears, you are at 'zero lash'.
As far as how much of a [CW] turn to make after reaching zero lash point, GM suggests 1 full turn. Many engine guys say 1/2 turn is correct. I have always used 3/4 turn with no bad results. The intent is to find the center of travel of the piston in the lifter.
Le Mans Master
Joined: Jan 2006
Posts: 6,499
Likes: 137
From: Butler Pa
If they're clacking, they're too loose. Assuming you're finding zero lash correctly, the only thing that could be wrong is the lifter is still on the lobe ramp. Are you bringing that piston to TDC on compression?
Burning Brakes
Joined: Nov 2006
Posts: 954
Likes: 40
2022 C3 of the Year Finalist - Modified
You can adjust them when the engine is running, take an old valve cover make holes where the nut and you don't have any oil mass on the engine.
When you change lifters it's recommend to change also the cam, it should be as a set.
Good luck
Avner
When you change lifters it's recommend to change also the cam, it should be as a set.
Good luck
Avner
Last edited by avner; Jul 20, 2010 at 11:37 AM.
Thread Starter
Drifting
Joined: Jan 2002
Posts: 1,645
Likes: 11
From: Schaumburg IL
Thanks guys. I need to "re-look for TDC for each cylinder and yes I have been spinning the pushrod. This week I'll jerk them up and down until all play is gone, then go with 3/4 of a turn after zero lash.
Pro
Joined: May 2010
Posts: 737
Likes: 3
From: Pennington NJ
When my friend and I did it on his '72 nova 396 bb, we replaced just the lifters and pushrods ( long story) and we found zero lash by tightening the nut until there was a little resistance with the spinning of the pushrod, then did 3/4 turn extra. It worked perfectly and his engine runs great today!
Will
Will
