Is what I describe a collapsed lifter...?

[5spd GT]

Okay, I recall when I was setting up my valvetrain I remember there was 2-3 lifters on where I could push in the "cup" on the lifter by hand when I pushed down on the pushrod. The other lifters did not do this and had to be tightened down to get preload on them. The potentially "bad" lifters (when I went to set them) would turn and then just "stop"...there wasn't much difference between lots of play and not being able to turn the pushrod at all with my fingers

13 of the other lifters were better...would those be considered collapsed? How could that effect performance...my car (according to the track times) aren't doing as good as I thought they would...

Any thoughts?

 

[TheBocSez]

I would think so, I had a similar problem with mine when adjusting the valves.

The rockers were noisey so I went to readjust the rockers. When I did, all except for 3 or 4 would slightly compress the valve as I tightened the poly lock.

The 3 or 4 in question, would compress the lifter and not the valve.

I have recently installed new lifters, should be running again sometime this week so we will see if it makes a difference.

 

[ryanp]

if the engine has been done for awhile then it could just be bled down...but if you had the engine running this week and then tore it down and they bleed down that fast then something is wrong....but that doesn't mean they won't pump back up when you start the engine and they get full oil pressure. If they are collapsed and not pumping back up then you will have lots of tapping noises coming from your valve covers! If no noise then they are pumping back up. Hope that helps. Either way I would change them...they are cheap and if you already got it all apart then you might as well!

 

[nmcgrawj]

Well isnt oil what actually keeps the lifters pumped up? So when setting up the valve train, there is no oil pressure to keep the lifter from collapsing. I would think a collapsed lifter would make a hell of a lot of noise. But i dont think it compressing with just putting your finger on it means much. Though, i could be wrong.