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1969 Firbeird 400 Lifter?

1K views 11 replies 5 participants last post by  camarodude67 
#1 ·
Hi All, This is my 69 Firebird Rebuilt 400 years ago, have a slight tick when you let off the accelerator, when you rev the motor all is good, oil pressure 60psi and 40psi when driving.

I removed the intake and there are no flattened lobes, changed the oil and was good.

Please skip to minute 4:00 to see motor running.



Any ideas?

Thanks
Jeff G.
 
#5 ·
But seriously, could be some varnish or dirt inside a lifter, especially if it has sat for a while. I have heard that you can add a quart of ATF and run it up to operating temp for a while, then drain and refill. Detergent in ATF will help clean the crud out of it.
 
#6 ·
Jeff, if you feel that you have a collasped lifter or several, sometimes a new lifter can be inserted but you have to make sure you apply a good amount of moly type past on the lifter bottom as this new lifter may not ride well on the used cam lobe. Understand?
Lifters are not flat as we may think , they have a concave bottom to act as a rotating device while riding on the lobe of the cam. If you have a lifter out, look into the lifter bore and you will notice that the cam lobe is not directly in center of the bore. Lifters spin in the bore and on the cam lobe.

You may get by with using one or two new lifters, but I suspect in some cases, the new lifter may destroy the cam lobe and that means a new cam. Just thought I would mention this. Pontiac hydraulic lifters are no different from chevy, unless they are roller lifters .

You may luck out and remove the lifter and soak it in Marvel Mystery oil, the red stuff like transmission fluid. Available at most auto parts stores and Walmart.
I have taken lifters apart and cleaned the little piddle valve inside.
 
#7 ·
Not to nitpick, but I am sure Don meant to say the lifter should have a convex bottom, not concave.

Personally, I would skip the ATF, or any other pour in fix. If the lifterr is collapsed, remove it, and either disassemble and clean, or replace it.

If you don't see an obvious problem, replace it. And yes, use moly lube and run it in the same as you would as if it were an all new cam and lifters.

Good luck.

BTW, cool car.
 
#8 ·
I'm not a believer in pour in fixes ( mechanic in a bottle). That being said. I had a 1999 Chevy Tahoe that had a noisy lifter. I drained out a quart of oil and added 1 quart of dex merk 3 and started the engine. It had about 80k miles on it. The lifter stopped making noise in about 30 seconds and never came back. I changed the oil and filter. Just sold ot with 200k miles and never had any other engine issues. For what it's worth. Transmission fluid won't fix a bad lifter but it may clean a dirty one. Good luck.
 
#9 ·
Guys, excellent replies and I understand what each of you are saying....Yes I'm going to replace the suspect lifers, soak the new ones in a bucket of oil, use Compcam break- in oil on the lobes/new lifter.

Again thank you very much for your support.

My Firebird is going away to a new owner and I just bought a 2 owner 1969 Camaro X77 from a team member here...

Jeff G.
 
#10 ·
Jeff, if that cam doesn't have a lot of miles on it, I think you may have a pretty good chance of success with a new lifter. I think someone makes a lifter that has a heavier duty face on it (stellite?). I have read that these are much less prone to the kind of failure that seems to be happening these days.

As Don said, the lifter has a convex face on it, but the cam lobe itself is also tapered to promote spin. When the cam lobe begins to wear, it becomes flat across its surface, and this keeps them from spinning. When this happen, wear accelerates. This is why even a new lifter with a good convex face might not last long if the cam has a lot of wear on it.

This is also the reason that roller cams need a button or retainer to keep them from walking out the front of the block. The taper on the cam lobes counteracts the tendency for the distributor gear to want to force the cam out the front of the engine. Roller cams are ground flat - no taper.
 
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