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Discussion Starter · #1 ·
So...
Ive never had an issue adjusting hydraulic lifters before today.
Ive always just gone to 0 lash and then a 1/2 turn plus an 8th to set the polylock and everything worked perfectly.
Working on a big block Chevy with a comp cams hydraulic retrofit roller cam and lifters.

Today I made sure I was on the base of the cam, got to 0 lash as usual but when getting to 1/2 turn it was starting to move the valve ? Its like the lifter is bottomed out ? This motor has been sitting for a while so I was thinking I must need to pre-lube the motor and get the lifters full of oil maybe ? Or, as the lifters have been run could they be full of oil still and not compressing internally at all ?

What am I missing here..lol Seems like a no brainer..
I was about out of time so I cleaned up and came inside until tomorrow after work anyway but it left me scratching my head ???
 

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It may have the higher rpm "short travel" hydro roller lifters. PLunger travel in the lifters is limited to just .020" or so, that way they can't pump up and float nor can they get aereated and collapse.
They require much less preload, what amounts to about1/8 turn down from zero lash.
Do you have a part number for the lifters?
 

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I would agree those are probably short clearance lifters that run with very little preload, by half a turn your probably bottoming the internal piston. I’ve always had the habit of running hydraulics just hair past zero preload.

I also set my final preload with the engine hot and running.

Bogie
 

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Discussion Starter · #6 ·
After looking through my stack of Summit receipts ( Never do that by the way...lol ) they arent Comp lifters, They are Howards 91161.
They should be standard travel hydraulic rollers.

Im thinking they were just pumped up full of oil still.
Im gonna tighten them all down enough that the valve spring is putting pressure on the lifters and let them sit for a bit.
Im hoping that will push the oil out and then I can adjust as normal.
 

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Well they do take some time to ooze down so you need to expect that. Some leak faster than others.

I never set the preload more than 1/8 past zero I do that with the engine hot and running. I usually just make a oil catcher from heavy weight aluminum foil so it’s cheap, moldable to my needs then I toss it in the recycle barrel when I’m done.

Bogie
 

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Sounds like it could be normal. If the lifters are full of oil this will happen. go the 1/2 turn and let the engine sit for a while and then go back and back off the adjusting nut until you can spin the pushrod and then tighten again to 1/2 turn. See if the valve stays closed.
 

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Discussion Starter · #9 ·
After letting them sit and bleed down I think all is good.
I was scratching my head for sure, Ive used a ton of comp and Howards roller lifters and never had thet happen before. Wierd, guess I was just lucky or I didnt notice.

I appreciate the replies though, I didnt know there was such a thing as short travel lifters before seeing it mentioned here and I looked them up.
 
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