[P-Fast]

Hi all,

While I was waiting for my head to be rebuilt, I decided to test my lifters. Attached is a video of how far most of my lifters compress. Takes about 15lbs of pressure I’d guess. One of them is stiffer. They have out of the car for about a month. Is this how far they compress when they are “soft”, or would they move further?

I also took each of them, submerged them in 15w50 oil, and pulled a vacuum to pull as much air out of them as I could. None of them changed in how they compress. Are all of the ones that compress like this bad, is this the amount they should move when primed, or do I need to do something more to prime them?

Thanks in advance!

[N0tt0N]

No idea on range of motion and #s needed.

I always cook mine in oil just below the point of the oil smoking in an aluminum foil 'basket' in a crappy pan on the gas grill outside to loosen up an crud that may have built up inside or in the passages. It also chases out air and primes them. Then I leave them submerged until I load them into the heads after they cool down.

[P-Fast]

Originally Posted by N0tt0N

No idea on range of motion and #s needed.

I always cook mine in oil just below the point of the oil smoking in an aluminum foil 'basket' in a crappy pan on the gas grill outside to loosen up an crud that may have built up inside or in the passages. It also chases out air and primes them. Then I leave them submerged until I load them into the heads after they cool down.

Thanks for the advice!

[TurboPooch]

I don't see video but I tested a couple that I have laying around and they compress about 1.5-1.7 mm. When I built the last race motor I cleaned the lifters and put them in a vacuum chamber with Marvel mystery oil and cycled going from atmospheric to full vacuum three times. This procedure evacuated all of the air and old oil out and replaced it with the Marvel. Upon startup I had no lifter noise whatsoever.

[P-Fast]

Originally Posted by TurboPooch

I don't see video but I tested a couple that I have laying around and they compress about 1.5-1.7 mm. When I built the last race motor I cleaned the lifters and put them in a vacuum chamber with Marvel mystery oil and cycled going from atmospheric to full vacuum three times. This procedure evacuated all of the air and old oil out and replaced it with the Marvel. Upon startup I had no lifter noise whatsoever.

This is good news! Billy also shared with me as I was picking up my reworked head that some compression is to be expected when the oil isn’t under positive pressure to be pushed into the chamber (even with the vacuum air evacuation), so I think I’m gonna call it good! Thank you for your insight on this.