Lifters (how they work)

[Omie01]

I installed a set of Lunati lifters (hydraulic) on top of a Comp cam, Comp one piece push rods, with Scorpion roller rockers. I also installed new valves, springs, keepers. (All upgraded pieces). My problem is, once the motor warms up, I swear I have a valvetrain tick somewhere. I called Lunati to double check lifter preload and they said between .030 - .040. I was told a 7/16 by 20 stud was .050 per full revolution of poly lock nut, so I set preload to just over half a turn which should be .030 - .035 preload. I pulled my valve covers off to see if I had any loose rockers and nothing abnormal popped up. I still suspect an improper preload issue, can anybody point me in a direction of something to check? The engine runs GREAT!! At first I suspected an exhaust leak, but just had a fully welded dual exhaust installed. So here's the question. When I went to reset preload on one of the lifters, I could swear there was no lifter plunger travel, and I gave it better than 5 minutes to bleed down before adjustment. What am I not understanding about how hydraulic lifter work? PS: I did make sure the lifter was on the back side of the cam lobe during adjustment as well. It seems to be most noticeable under load with engine up to temp, and seems to go away at idle, or under normal cruising speed. Any insight would be very helpful!!

 

[MeZapU]

You will have some noise using pushrod guide plates. Are you sure it is not that? I'm not sure if you are running them based on your post.

 

[barnett468]

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i would adjust them while its running . . could also be a pos lifter or a cam lobe going flat which is usually caused by improper break in.

 

[Omie01]

I am running guide plates, but they have little plastic insulators on them. I am using the Crane stud conversion kit. My dyno shop did the break-in, we used break in oil, ran it for 20 min @ 2000rpm, and 3 min @ 2800rpm. The cam was fully lubed during install.

 

[c9zx]

"It seems to be most noticeable under load with engine up to temp, and seems to go away at idle, or under normal cruising speed." This is nothing but a wild guess but, could it be detonation or preignition? Do you know the compression ratio, cam specs, fuel octane, and the heat range of the spark plugs? Chuck

 

[Don C]

"It seems to be most noticeable under load with engine up to temp, and seems to go away at idle, or under normal cruising speed." This is nothing but a wild guess but, could it be detonation or preignition? Do you know the compression ratio, cam specs, fuel octane, and the heat range of the spark plugs? Chuck

+1

In my experience lifter noise is worse at idle. Another thing to check is spark plug wires and distributor cap. Arcing spark makes a noticeable clicking noise. When the engine is under load the spark plugs are also under load, and any defects in the ignition system will show up.

 

[Jeff73Mach1]

"It seems to be most noticeable under load with engine up to temp, and seems to go away at idle, or under normal cruising speed." This is nothing but a wild guess but, could it be detonation or preignition? Do you know the compression ratio, cam specs, fuel octane, and the heat range of the spark plugs? Chuck

+1

In my experience lifter noise is worse at idle. Another thing to check is spark plug wires and distributor cap. Arcing spark makes a noticeable clicking noise. When the engine is under load the spark plugs are also under load, and any defects in the ignition system will show up.

I agree, plus it is easy to test. mark the distributor location and rotate it to retard the timing a few degrees and see if that makes it go away. If not return to your distributor to the mark and keep searching

 

[Omie01]

I thought about the pre-ignition thing too, does that sound like a ticking lifter/rocker? I have tried other timing positions on my dizzy, and where it is set seems to be its favorite setting. If I turn it at all performance losses are VERY noticeable, and from all my research the timing is spot on to recommended timing on these motors. I'm fairly sure its in the valve train somewhere, but I'm not sure where to start. I would like to reset the preload on my lifters/rockers, but I'm not sure if they need more or less? What would it hurt if I maybe try one full turn past zero lash? What is the normal consequence to too much preload? I just don't want to damage anything at this point as I don't have any more money to put into it right now.

 

[Jeff73Mach1]

too much preload does not allow the valve to contact the seat completely. It therefore cannot dissipate heat and will warp or burn.

If you are convinced it is mechanical noise, then get an old valve cover and cut the top out of one and adjust while running until the noise just stops.

The old valve cover will prevent a fairly large mess.

 

[jbojo]

I preloaded mine about 5/8 of a turn. I still get some noise but I am using Rhoades lifters and they tend to be noisy. I verified it with Rhoades and they said I was fine.

 

[barnett468]

I thought about the pre-ignition thing too, does that sound like a ticking lifter/rocker? I have tried other timing positions on my dizzy, and where it is set seems to be its favorite setting. If I turn it at all performance losses are VERY noticeable, and from all my research the timing is spot on to recommended timing on these motors. I'm fairly sure its in the valve train somewhere, but I'm not sure where to start. I would like to reset the preload on my lifters/rockers, but I'm not sure if they need more or less? What would it hurt if I maybe try one full turn past zero lash? What is the normal consequence to too much preload? I just don't want to damage anything at this point as I don't have any more money to put into it right now.

the factory timing settings are less than optimal for all the engines.

if you adjust them with it running as i suggested you will know exactly what lifter it is.

you can turn the nut 2 full turns from 0 before the lifter bottoms but if it is still noisy after 1 full turn it wont get quieter with 2.

your break in info wasnt detailed and much more than that needs to be done to insure proper break in . . if you have open spring rates of 280 or more, you can damage the cam during break in if you have non roller lifters.