Valve adjustment and finding 0 lash
Thread Starter
Racer
Joined: Jul 2005
Posts: 433
Likes: 14
From: GA
Valve adjustment and finding 0 lash
Most of the "valve adjustment" procedures want you to twirl the pushrod until feeling a "slight" drag to signal 0 lash. I guess I'm a bad at "twirling" because I still end up with a noisy valve train.
I have read about moving the pushrod "up and down" until it stops and this signals 0 lash. This seems to work better but is it a better method?
Thanks
I have read about moving the pushrod "up and down" until it stops and this signals 0 lash. This seems to work better but is it a better method?
Thanks
Race Director
Joined: Nov 2006
Posts: 13,199
Likes: 7,796
From: Sunshine Coast, Queensland, Australia
2025 C3 of the Year Finalist - Modified
2024 C3 of the Year Finalist- Modified
2022 C3 of the Year Finalist - Modified
Cruise-In VIII Veteran
What are we adjusting here Jim? Solids or hydraulic's? Hydraulic's are fairly forgiving. Have you tried adjusting the "Bubba" way? With valve cover off and engine idling , loosen rocker arm nut just till you hear it click. Slowly tighten till the click is gone, then half turn down. Then the next one and so on.
Race Director
Joined: Nov 2006
Posts: 13,199
Likes: 7,796
From: Sunshine Coast, Queensland, Australia
2025 C3 of the Year Finalist - Modified
2024 C3 of the Year Finalist- Modified
2022 C3 of the Year Finalist - Modified
Cruise-In VIII Veteran
Believe it or not, it's really not that messy at idle. None the less, you need to learn to feel zero lash. Spinning works best for me.
Le Mans Master
Joined: Aug 2017
Posts: 8,336
Likes: 2,810
From: Cool Northern Michigan
If you have stock style rockers, they sell clips to contain the oil spray. Come in sets of 8.
Then, using a strip of cardboard, install that between the springs and the valve cover ledge to divert oil.
No mess. Just don't rev it.
Then, using a strip of cardboard, install that between the springs and the valve cover ledge to divert oil.
No mess. Just don't rev it.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,117
From: Crossville TN
Use the "shake" method: With pushrod lightly held between thumb and fingers of one hand, continuously shake the pushrod up & down to feel the 'slop' in the system. With the other hand, slowly tighten the adjustment nut. You can EASILY find the point of 'zero lash' with this method.
Once you are skilled at the 'shake' method, your sense of feel becomes better for this process and the 'spin' method becomes easier to achieve. But, I still prefer the 'shake' method....it is almost fool-proof.
Once you are skilled at the 'shake' method, your sense of feel becomes better for this process and the 'spin' method becomes easier to achieve. But, I still prefer the 'shake' method....it is almost fool-proof.
Last edited by 7T1vette; Aug 8, 2020 at 11:40 AM.
Le Mans Master
Joined: Mar 2004
Posts: 7,477
Likes: 1,495
From: Little Rock AR
The "up and down" method is great for a first timer. If someone is asking how to adjust hydraulic lifters, that is a very good answer.
Once you have done that a few times, you can actually "feel" what a push rod feels like when the lifter is adjusted right. Spin it and feel the drag after you are done setting them. The drag is very slight due to all the hard oily steel in the assembly.
There is no good way to describe online the "feel" of it unless you already know. If it was easy, there would not be SOO many threads on it and SOO many different answers regarding the method and particularly the (exact??? really???) turns past zero. The number of turns past zero is in no way critical. You need enough turns to account for any potential future valve train wear and not soo much turns that you run out of adjustment travel inside the lifter. If you are too loose there is a gap and you can hear it. Too tight and the valve never seats so the engine runs bad. The lifters are not at all fussy about it so why are we all???
Once you have done that a few times, you can actually "feel" what a push rod feels like when the lifter is adjusted right. Spin it and feel the drag after you are done setting them. The drag is very slight due to all the hard oily steel in the assembly.
There is no good way to describe online the "feel" of it unless you already know. If it was easy, there would not be SOO many threads on it and SOO many different answers regarding the method and particularly the (exact??? really???) turns past zero. The number of turns past zero is in no way critical. You need enough turns to account for any potential future valve train wear and not soo much turns that you run out of adjustment travel inside the lifter. If you are too loose there is a gap and you can hear it. Too tight and the valve never seats so the engine runs bad. The lifters are not at all fussy about it so why are we all???
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Top 10 Corvette Engines RANKED by Peak Torque (70+ Years of Muscle!)
Joe Kucinski
Corvette ZR1X Will Be Pacing the Indy 500, And Could Probably Race, Too!
Verdad Gallardo
Top 10 Corvettes Coming to Mecum Indy 2026!
Brett Foote
Le Mans Master
Joined: Oct 2002
Posts: 7,098
Likes: 378
From: Las Vegas - Just stop perpetuating myths please.
Are you adjusting the lifters with the engine running? If not you need to follow the procedure to find zero lash on the lifter you are adjusting. If you can't provide us with correct information because you are trying to hide your error then we can't help you. Too many beginners are in denial they don't really understand what they are doing and setting lifter preload is very critical to protecting the camshaft and lifters from self-destruction.
Drifting
Joined: Aug 2019
Posts: 1,334
Likes: 225
Are you adjusting the lifters with the engine running? If not you need to follow the procedure to find zero lash on the lifter you are adjusting. If you can't provide us with correct information because you are trying to hide your error then we can't help you. Too many beginners are in denial they don't really understand what they are doing and setting lifter preload is very critical to protecting the camshaft and lifters from self-destruction.
Advanced
Joined: Nov 2016
Posts: 95
Likes: 28
From: Southern MD
I find that it is very easy to feel with the up/down of the push rod. Moving the push rod up and down and slowly adjusting the rocker nut until no up/down motion is felt gets you there. Doing it this way doesn't matter whether the lifters have been filled with oil or not. You get to the zero lash position and give it 3/4 of a turn and you are done.
Thread Starter
Racer
Joined: Jul 2005
Posts: 433
Likes: 14
From: GA
Are you adjusting the lifters with the engine running? If not you need to follow the procedure to find zero lash on the lifter you are adjusting. If you can't provide us with correct information because you are trying to hide your error then we can't help you. Too many beginners are in denial they don't really understand what they are doing and setting lifter preload is very critical to protecting the camshaft and lifters from self-destruction.
a
Melting Slicks
Joined: Oct 2003
Posts: 2,176
Likes: 822
From: Chapel Hill NC
2025 c3 ('68-'73) of the Year Finalist - Unmodified
2025 C4 of the Year Finalist - Unmodified
2025 C8 Stingray of the Year Finalist - Unmodified
Strictly an amateur here. Recently adjusted the valves on my BB 71 with engine running. Did not use any clips and the cardboard I placed at the bottom of the heads had no oil on them when I was done. I made sure the engine was warm enough before starting so the idle was as low as possible.
Le Mans Master
Joined: Oct 2002
Posts: 7,098
Likes: 378
From: Las Vegas - Just stop perpetuating myths please.
I'm not trying to hide anything. Im asking if the "shake" method is as good/better than the "twirl" method for finding 0 lash. I used Lars procedure to adjust the valves the first time while the engine was still on the stand. My only deviation was I didn't mark the damper at 90° intervals because the intake was off and I could easily see when each pistons valves where closed. Following the FO I twirled the pushrod while tightening the adjustment nut until I felt a slight drag(I thought) and then 1/2 turn for preload. I also used the Lars method to insert the distributor and set initial timing(8° BTDC). I put the engine on my run stand, and hit start. It started and ran for 30 minutes at 2200 to 2500 rpm. The valve train just seemed noisy to me.
a
a
Without being there I can't say you did anything wrong. But the results don't sound good. Something else that I don't like to hear is using less than 1 full turn pre-load. I don't care how many or who says to use less you won't find any shop manuals saying use less than one full turn. The excuse given is if you run the engine to high enough RPM to make the valve float it will pump up the lifters and hold the valves open. Well you should never run the engine past redline regardless so it shouldn't be an issue unless you frequently abuse your engine past the cam redline enough to break it.
So I don't know what your looking for if you say you adjusted the lifters correctly on base circle and at zero lash. Lifters make noise when their loose (not tight) so either there's not enough pre-load or the lobes are wiped already. Sorry to be so pessimistic but from my own experience I know a cam lobe will wipe in a few minutes - before the 20 min break-in is done. It will be unbelievable and hard to admit to yourself if it happens but a lesson not forgotten. Once you pull out the noisy lifter and see for yourself you can't deny it.
Disabled by request 8 JUN 2025
Joined: May 2019
Posts: 329
Likes: 94
From: St. Augustine, FL
Another Method
Another way that has been referred to here before (I think it was Rescue Rogers) is to throw away the lock nuts and use poly locks. With the set screw in the poly lock backed out some, slowly turn the poly lock down between your fingers until you encounter some résistance. That is zero lash. From there turn down the required number of turns (your choice) and then while holding the poly lock with a wrench, tighten the set screw. I find that locating zero lash using is procedure is easier than the "twirling" method. NOTE: if using stock valve covers make sure the valve cover clears the poly lock.
Le Mans Master
Joined: Dec 2006
Posts: 8,837
Likes: 1,028
Without being there I can't say you did anything wrong. But the results don't sound good. Something else that I don't like to hear is using less than 1 full turn pre-load. I don't care how many or who says to use less you won't find any shop manuals saying use less than one full turn.
If you do a 1/2 turn preload, you gain a tad of of HP.
If you live long enough to trash a lifter that way, happy days.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,117
From: Crossville TN
I don't believe there is any advantage to setting hydraulic valves on a running engine. Nothing against doing that...but, to me, it's just unnecessary. For solid lifters, gotta be running, for me.
I agree with the above post about the 'amount' of pre-loading needed for hydraulic lifters (on Chevy engines). GM wanted 1 turn...just like they wanted to set ignition timing at 8* BTDC (or even more retarded than that!). For the average enthusiast, 3/4 turn (CW) after zero lash seems about right to me. If you are trying to get more revs out of the engine before the valves float, 1/2 turn is better, IMO.
I agree with the above post about the 'amount' of pre-loading needed for hydraulic lifters (on Chevy engines). GM wanted 1 turn...just like they wanted to set ignition timing at 8* BTDC (or even more retarded than that!). For the average enthusiast, 3/4 turn (CW) after zero lash seems about right to me. If you are trying to get more revs out of the engine before the valves float, 1/2 turn is better, IMO.
Le Mans Master
Joined: Oct 2002
Posts: 7,098
Likes: 378
From: Las Vegas - Just stop perpetuating myths please.
Your spreading disinformation. No, no, no, less preload preload reduces lift and makes less power. That's a fact Jack. The greater the preload the less the little piston inside the lifter can travel when compressed by the cam lobe and valve spring and the less lift is lost by the lifter. The greater the preload the higher the valve lift and the more power tge engine will make. The less lifter preload used the more that little piston inside the lifter can travel/compress and the greater the lift is lost.
It's assuming posters that don't know how a lifter works or what preload does that perpetuate stupid assumptions. Get pictorial of a hydraulic lifter and figure it out for yourself. And please stop posting bad information.
Drifting
Joined: Jul 2015
Posts: 1,765
Likes: 254
From: Catlett VA
I thought I would check out the Corvette Forum to get away from all of the arguments on facebook between competing political parties. I think I will go back to fb to get away from the valve lash fanatics! 
Dr. Detroit
Joined: Mar 2012
Posts: 10,097
Likes: 4,027
From: New Braunfels Texas
Another way that has been referred to here before (I think it was Rescue Rogers) is to throw away the lock nuts and use poly locks. With the set screw in the poly lock backed out some, slowly turn the poly lock down between your fingers until you encounter some résistance. That is zero lash. From there turn down the required number of turns (your choice) and then while holding the poly lock with a wrench, tighten the set screw. I find that locating zero lash using is procedure is easier than the "twirling" method. NOTE: if using stock valve covers make sure the valve cover clears the poly lock.
Spin it tighter with your fingers and when zero lash happens......you can feel the spring in the bottom of the lifter start to plunge.......roll it back and forth from this spot to verify, from there....do your half turn and lock. Perfect everytime.
FYI.....I also use the TDC through the firing order method....each cylinder is at TDC...adjust both valves at that cylinder.
Jebby