Hydraulic Roller Lifter Preload Issue
Thread Starter
Racer
Joined: May 2020
Posts: 498
Likes: 167
Hydraulic Roller Lifter Preload Issue
So… I have a new 383, with Melling hydraulic roller lifters and I can’t seem to get some of them to preload properly. I’ve tried two different techniques to preload them. The first way by going down the firing order and preloading them individually and the batch method - rotating the engine a quarter turn until you get zero lash on all lifters. Either way the rockers start to tick once the engine warms up and when I take the valve covers off several of the rockers are loose. Mostly on the exhaust side…
The rockers are Howard’s aluminum full roller rockers with poly locks. After zero lash, I set the preload by half a turn and then lock them down.
My worst fear is I have some bad lifters… But I’ve read that oil viscosity can have an effect on lifter preload as well.
My oil pressure is around 50-60 psi so I am wondering what is going on….
The engine only has about 50 miles on it, so should I increase the oil weight to see if this fixes the problem??? Or should I rip the bandaid and put new lifters in it…
The rockers are Howard’s aluminum full roller rockers with poly locks. After zero lash, I set the preload by half a turn and then lock them down.
My worst fear is I have some bad lifters… But I’ve read that oil viscosity can have an effect on lifter preload as well.
My oil pressure is around 50-60 psi so I am wondering what is going on….
The engine only has about 50 miles on it, so should I increase the oil weight to see if this fixes the problem??? Or should I rip the bandaid and put new lifters in it…
Last edited by JC 1975; Feb 22, 2023 at 11:02 AM.
Dr. Detroit
Joined: Mar 2012
Posts: 10,095
Likes: 4,025
From: New Braunfels Texas
Go one full turn and see if the noise goes away......if it does then you are either doing it wrong or there is a lifter manufacturing issue......
You will not hurt anything going one full turn......I just do not lash them that tight as they will have a greater tendency to pump up at high RPM.
Jebby
You will not hurt anything going one full turn......I just do not lash them that tight as they will have a greater tendency to pump up at high RPM.
Jebby
Team Owner
Joined: Apr 1999
Posts: 21,953
Likes: 1,445
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
Are you getting some pushrod spinning resistance and then doing an extra 1/4 - 1/2?
IMO hlifter failure is much less likely than new cam lobe failure.
Oil pressure is determined by oil weight in its engine environment. Clearances, block types, oil pump types, feasibly even oil restrictors to the top end.
Roller lifters need about 30 at hot idle and 50 60 psi say at 4500 to redline. The old guide was 10 psi for every 1000 rpm.
IMO hlifter failure is much less likely than new cam lobe failure.
Oil pressure is determined by oil weight in its engine environment. Clearances, block types, oil pump types, feasibly even oil restrictors to the top end.
Roller lifters need about 30 at hot idle and 50 60 psi say at 4500 to redline. The old guide was 10 psi for every 1000 rpm.
Thread Starter
Racer
Joined: May 2020
Posts: 498
Likes: 167
Yep, tried that both ways. In fact I am going to do it again… to try to get this preload issue worked out.
I would be surprised and upset if it was the lobe… Unless the engine builder installed the lifters wrong. It’s possible I guess, seen it happen to other people.
Everything is roller in this engine… Cam, lifters, rockers, timing chain,… lol…
I would be surprised and upset if it was the lobe… Unless the engine builder installed the lifters wrong. It’s possible I guess, seen it happen to other people.
Everything is roller in this engine… Cam, lifters, rockers, timing chain,… lol…
Dr. Detroit
Joined: Mar 2012
Posts: 10,095
Likes: 4,025
From: New Braunfels Texas
I want to try to explain how I find zero lash with Poly-Locs….
With the poly-loc loose….spin it back and forth with your thumb and forefinger to verify it is indeed loose and no hangups on the threads….Now tighten slowly with your fingers until to feel the slightest resistance….I spin it slightly back and forth just a bit and get a “feel” for this resistance….THIS is zero lash…now go you half turn. I never spin a pushrod to find zero….it is better to wiggle it up and down, BUT…this can cause errors if you are not 100% sure where you are at. Think about it….when the lash is taken up and the plunger in the lifter just starts to compress….you will feel this in your fingers tightening…..try it, it is easy as **** once you get the feel for it.
Jebby
With the poly-loc loose….spin it back and forth with your thumb and forefinger to verify it is indeed loose and no hangups on the threads….Now tighten slowly with your fingers until to feel the slightest resistance….I spin it slightly back and forth just a bit and get a “feel” for this resistance….THIS is zero lash…now go you half turn. I never spin a pushrod to find zero….it is better to wiggle it up and down, BUT…this can cause errors if you are not 100% sure where you are at. Think about it….when the lash is taken up and the plunger in the lifter just starts to compress….you will feel this in your fingers tightening…..try it, it is easy as **** once you get the feel for it.
Jebby
Le Mans Master
Joined: Aug 2017
Posts: 8,336
Likes: 2,809
From: Cool Northern Michigan
JC,
You need to verify 100% that your rocker nuts are not moving. What type / brand of fasteners are you using?
I would take the V.C. off. Take a shop towel and clean off any oil on the rocker stud & adj nut. Using a white paint pen, mark a line on the stud and nut.
Put everything back together, run it for a few minutes, pull the VC again and check your reference paint mark.
I have had big name brand nuts back off before. Clack-clack-clack-
You need to verify 100% that your rocker nuts are not moving. What type / brand of fasteners are you using?
I would take the V.C. off. Take a shop towel and clean off any oil on the rocker stud & adj nut. Using a white paint pen, mark a line on the stud and nut.
Put everything back together, run it for a few minutes, pull the VC again and check your reference paint mark.
I have had big name brand nuts back off before. Clack-clack-clack-
Last edited by HeadsU.P.; Feb 22, 2023 at 08:44 PM.
Thread Starter
Racer
Joined: May 2020
Posts: 498
Likes: 167
JC,
You need to verify 100% that your rocker nuts are not moving. What type / brand of fasteners are you using?
I would take the V.C. off. Take a shop towel and clean off any oil on the rocker stud & adj nut. Using a white paint pen, mark a line on the stud and nut.
Put everything back together, run it for a few minutes, pull the VC again and check your reference paint mark.
I have had big name brand nuts back off before. Clack-clack-clack-
You need to verify 100% that your rocker nuts are not moving. What type / brand of fasteners are you using?
I would take the V.C. off. Take a shop towel and clean off any oil on the rocker stud & adj nut. Using a white paint pen, mark a line on the stud and nut.
Put everything back together, run it for a few minutes, pull the VC again and check your reference paint mark.
I have had big name brand nuts back off before. Clack-clack-clack-
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Instructor
Joined: Aug 2002
Posts: 244
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From: Moneta Virginia
Setting and verifying lash
After doing this a bunch of times now when I adjust the valves I set zero as described and then take a paint pen and put a dot or line at 12 o’clock. Then rotate the poly by 1/2 or 3/4 turns whichever you prefer. Tighten your lock and you now have visual reference that allows you to check that nothing move as you locked it down and also after it has been run, open a valve cover and if a dot is at 3 o’clock you know where to start. I do this because I’m old and forgetful this way I know if I missed anything during setting steps.
just saw the previous post, sorry to duplicate
just saw the previous post, sorry to duplicate
Thread Starter
Racer
Joined: May 2020
Posts: 498
Likes: 167
Yes, they state a half turn. I may have found the culprit. Last night I relashed the loose rockers to zero. Then rotated the engine by one hand while keeping the other on the rocker nut that I was having trouble with. I noticed when the lifter started go back down I would get more slack in the nut. Then I looked at the pushrod / guide plate clearance and wondered if the pushrod is binding somewhere causing the lash issue by not sitting square in the rocker arm. The pushrod clearance is real tight. It’s not an aggressive cam 222/232 @ 50.
Race Director
Joined: May 2006
Posts: 18,690
Likes: 2,572
Yes, they state a half turn. I may have found the culprit. Last night I relashed the loose rockers to zero. Then rotated the engine by one hand while keeping the other on the rocker nut that I was having trouble with. I noticed when the lifter started go back down I would get more slack in the nut. Then I looked at the pushrod / guide plate clearance and wondered if the pushrod is binding somewhere causing the lash issue by not sitting square in the rocker arm. The pushrod clearance is real tight. It’s not an aggressive cam 222/232 @ 50.
Le Mans Master
Joined: Aug 2017
Posts: 8,336
Likes: 2,809
From: Cool Northern Michigan
I like the concept of those Isky plates. You can adjust one side without disturbing the other. Pricey though.
The plate on the right looks beat to death. Pull the pushrod and roll it on a piece of glass. Bent?
The plate on the right looks beat to death. Pull the pushrod and roll it on a piece of glass. Bent?
Thread Starter
Racer
Joined: May 2020
Posts: 498
Likes: 167
So I read this article from Engine labs that oil viscosity has a dramatic effect on lifter preload.
https://www.enginelabs.com/engine-te...problem-today/
Also read on an LS forum a guy was losing power as the oil got older by evidence of his track times and switched over to 20w50 and saw a noticeable improvement.
My preload issue is only happening when the engine warms up now, so I’m going to drain the 10w30 that’s in it and run 20w50 to see if this solves the issue. $35 oil change is cheaper and easier than putting in new lifters…
If this doesn’t work, I say screw it and put in solid rollers…
https://www.enginelabs.com/engine-te...problem-today/
Also read on an LS forum a guy was losing power as the oil got older by evidence of his track times and switched over to 20w50 and saw a noticeable improvement.
My preload issue is only happening when the engine warms up now, so I’m going to drain the 10w30 that’s in it and run 20w50 to see if this solves the issue. $35 oil change is cheaper and easier than putting in new lifters…
If this doesn’t work, I say screw it and put in solid rollers…
