Is this normal, lifters?
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Joined: May 2008
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Is this normal, lifters?
This winter I rebuild my 350 LT1, Hot cam, TF heads, new LS7 lifters. I have some lifter noise, just sounds like the lifters are letting the valves hit the seats a little harder than normal. Have adjusted the preload 3 times now. First two times 1/2 turn, last time 3/4 turn, seemed to help reduce noise some. The strange thing I notice when adjusting preload is this; on cyl's 5 & 7 when I set to 0 lash (hydraulic lifters obviously) then turn to 3/4 preload there is absolutely no resistance from the lifter, I can set the preload with my fingers. All the other lifters I have to use a 5/8" wrench to turn the lock nut against the pressure in the lifter, is this telling me something is wrong with the lifters with no resistance?
Safety Car
Joined: Apr 2011
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This winter I rebuild my 350 LT1, Hot cam, TF heads, new LS7 lifters. I have some lifter noise, just sounds like the lifters are letting the valves hit the seats a little harder than normal. Have adjusted the preload 3 times now. First two times 1/2 turn, last time 3/4 turn, seemed to help reduce noise some. The strange thing I notice when adjusting preload is this; on cyl's 5 & 7 when I set to 0 lash (hydraulic lifters obviously) then turn to 3/4 preload there is absolutely no resistance from the lifter, I can set the preload with my fingers. All the other lifters I have to use a 5/8" wrench to turn the lock nut against the pressure in the lifter, is this telling me something is wrong with the lifters with no resistance?
Each is different. IMO what you are seeing/feeling is additional slack in the lifter/pushrod/rocker.
Have you gone further to see exactly when and where you DO feel resistence? That would be my next step...run it down a little more and if its not totally unreasonable, try it.
Lifter racket tells you something...that tolerances are too loose and that parts are beating each other to generate that noise. Beating parts are wear parts. A slight 'tic' is one thing.Injectors tic...
Clatter or tapping is unacceptable.
The lifter and rocker are just a means of transmitting directional energy thru solid/hyd coupling. A slight pretension will take the hard slamming of the valve closing away to some degree but it may be more of a spring issue being too stiff for that set-up.
Le Mans Master
Joined: May 2004
Posts: 5,866
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From: Hellinois
Finalist 2020 C4 of the Year - Modified
I am right in the middle of a cam change in my '85 simply becuse I had a loud ticking I could not take care of by adjust rockers. I went all the way to one full turn past zero and at that point the engine wouldn't start. I just gave up & ordered a new cam & lifters, springs, etc. My concern is that I have yet to find a reason for the noise. All lifters are pumped up good, cam is perfect, I can only hope that I am overlooking something and it will be normal when I get it back together. Good luck finding yours.
Le Mans Master
Joined: Jul 1999
Posts: 8,683
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From: Phoenix AZ
I just adjusted my Comp R lifters about a month ago. The "normal" adjustment I used to do on other lifters was 1/4-1/2 turn past zero, after the lifters had bled down.
On the Comp R's it's much different. Slightly under an 1/8 of a turn is all that's needed past zero after they have bled down.
As stated different lifters can require a different adjustment to make them work.
On the Comp R's it's much different. Slightly under an 1/8 of a turn is all that's needed past zero after they have bled down.
As stated different lifters can require a different adjustment to make them work.
