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View Full Version : Before I go to far !!!



shagmebabe
07-30-2006, 09:32 AM
I just installed new heads on my new short block , got all the goodies on and getting ready for installation. My question is this........ on the valve adjustment for hydro lifters...... is it a 1/4 turn after zero lash or 1/2 turn after zero or a full turn. I have heard it all and I dont want to get everything in and have to readust the valves because I was a dumbass. I would have to take off the exhaust just to get to the valve covers.
And as a person that knows little about hydro lifters....... how much to they change when they pump up ? I have ran nothing but solid lifters in the past and Im curious.
I have a 1/4 turn after zero now and the rockers can wiggle a bit ..... it that right ?

YeLLowBoaT
07-30-2006, 09:33 AM
zero las + half a turn.

shagmebabe
07-30-2006, 11:35 AM
Thanks..... I guess Im heading back to the garage. But on the lifters when they pump up , how much in thousands do they pump up ?

mike37
07-30-2006, 12:09 PM
Thanks..... I guess Im heading back to the garage. But on the lifters when they pump up , how much in thousands do they pump up ?
dont over think it give them the 1/2 to 1 turn after o lash and your good
the oil will do the rest just be sure you have them at 0 lift when you set them

steelcomp
07-30-2006, 12:23 PM
I just posted this in another therad, but an old trick with hyd's is to set them at .000-.001" lash. Then they can't pump up. Of course, this is going to require maintenance checks just like solids, so throw out the benefit of hyd's. If you want to pre-load them, then you need to go by the mfgr. recommendation. The idea of preloaring them is to get the lifter's internal piston somewhere near the center of it's travel, which can be different between lifter mfgrs. OEM is usually about 1 turn, performance lifters can go as little as 1/4, which is only about .012" on a BB Chev. The amount they will pump up will be equal to the amount you preload them. With 7/16" studs, it's .050" per turn.
Rockers can wiggle without oil pressure. No big.

shagmebabe
07-30-2006, 12:26 PM
Thanks guys ,your imput is very much appreciated

DMOORE
07-30-2006, 12:52 PM
I gotta agree with Steelcomp. You really need to check the manufactures recomendations for preload. I've seen anywhere from 1/8 to 1/2, depending which brand.
Darrell.

SmokinLowriderSS
07-30-2006, 03:35 PM
Agreed. What's the lifter maker say?
My Iskys said 1/4 turn, and they are running happy. I recall 1/2 to 3/4 turn from factory GM's, but I haven't set any of those in a VERY long time.

GofastRacer
07-30-2006, 06:33 PM
The factory specs are for stock grocery getter stuff and allows for cam wear over time, any high performance application shouldn't have more than a 1/4 turn, actually all you need is enough to keep the plunger from hitting the retainer!..

jkh04200
07-31-2006, 05:09 AM
I'd definatley go 3/4 turn from zero. I set mine at a 1/4 and lost a rocker arm. Then I set at 1/2 and lost a rocker arm. Now there at 3/4 and its been 2 summers. I have run the guts out of it. Just My .02

shagmebabe
07-31-2006, 07:42 AM
So....... If I go to little ,my rockers could come off and if I go to much ,the valves wont close. I believe these are comp cam lifters. So if I go 1/2 could that be the best of both worlds ??

ghittner
07-31-2006, 09:50 AM
Go 1/2 and you will be safe, I run mine at 1/8th they are anti pump ups though. 1/2 and everyone will be happy! The point here is to get the plunger into the middle (or so) of the lifter bore to allow for some cushion either way. If you are too little you will hear the clatter immediately. 1/2 will not be too much but a little more than you need for peace of mind.