valve adjustment with rollers???
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Instructor
Joined: Aug 2001
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From: westmoreland n.h.
valve adjustment with rollers???
just had valves replaced in heads.whats the best way to adjust roller rockers with hydraulic lifters. tried the haynes repair manual way , and they still tick. :confused:
Drifting
Joined: Jan 2002
Posts: 1,645
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From: Schaumburg IL
Re: valve adjustment with rollers??? (dash8)
Rollers will adjust the same as stamped steel. Tighten to zero lash and 1/2 turn. That's what I use. The amt of turn after zero is up to you. There are various methods in the FAQ that work fine.
Race Director
Joined: Jan 2000
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From: San Jose CA
Re: valve adjustment with rollers??? (dash8)
Are you positive the tick isn't a burnt spark plug wire or a bad exhaust manifold gasket? I had something that sounded very much like a bad lifter adjustment and it turned out to be a burnt spark plug wire.
-Steve
-Steve
Le Mans Master
Joined: Apr 2002
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From: Boston
Re: valve adjustment with rollers??? (bigvette1)
Rollers will adjust the same as stamped steel. Tighten to zero lash and 1/2 turn. That's what I use. The amt of turn after zero is up to you. There are various methods in the FAQ that work fine.
I've always know to do it at zero lash, then to go with a 1/4 of a turn at a time, if they still made noise till it stops.
Paul
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From: Living in the Hartland
Re: valve adjustment with rollers??? (Pacin'California)
Mine was the exhaust gasket crushed from my caveman tightening job then it burnt/blow out.
Me thinks tighter better. :) :crazy: (Ok insert tighter jokes here.)
Racer
Joined: Mar 2002
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From: honolulu HI
Re: valve adjustment with rollers??? (inferno-vette)
WHAT DOES ZERO LASH MEAN... :confused: i was wanting to check mine soon and wondering what is meant by this statement..tighten by hand untill tight?
Drifting
Joined: Jan 2002
Posts: 1,645
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From: Schaumburg IL
Re: valve adjustment with rollers??? (dash8)
Zero lash is the point when you are tightening the rocker nut and slowly turning the pushrod between your fingers and the slack or ability to turn the rod stops. The adjust 1/4 to 1/2 turns based upon yoou needs.
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Le Mans Master
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From: Canada
Re: valve adjustment with rollers??? (bigvette1)
So why is it then that some engines require that you stop at zero lash and other need the 1/4 plus turn? does it have to due with the hardness of the rods that you are using, length, spring rate, or type of rockers?
[Modified by gdh, 11:25 PM 7/1/2002]
[Modified by gdh, 11:25 PM 7/1/2002]
Drifting
Joined: Nov 2000
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From: Honolulu Hawaii
Re: valve adjustment with rollers??? (gdh)
So why is it then that some engines require that you stop at zero lash and other need the 1/4 plus turn? does it have to due with the hardness of the rods that you are using, length, spring rate, or type of rockers?
BUT, there is another type of hydraulic lifter called "anti pump-up" lifters that, for some reason that someone else can explain, REQUIRES zero lash or very close to it for proper operation. A lot of performance cams that have matching lifters come with anti pump-ups. The Edelbrock Performer RPM package, the Holley System Max package, and some Crane and Comp Cams cam & lifter sets either come with anti pump-ups or are offered the option to have them.
As I've said before, know what kind of lifters you have before you adjust them. At times I felt like I'm the only one trying to get this message out. Some support would be nice. ;)
Drifting
Joined: Jan 2002
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From: Schaumburg IL
Re: valve adjustment with rollers??? (nunus79)
Very good explaination of the zero lash. All I wish to add is the 1/4 to 1 turn beyond zero lash is the design of the lifer by also funcitons as a built in rev limiter. Many GM manuals call for 1 turn. GM origionally came up with this as a way to "protect" the engines for 100k miles or so. The performance world found out that a looser 1/4 to 1/2 got you higher RPM's. Now anti pump up lifers can survive with "zero lash".
Race Director
Joined: Mar 2001
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From: Living in the Hartland
Re: valve adjustment with rollers??? (bigvette1)
My understanding of the hyd lifter setting is that as all the components wear, the lifter fills with a little more oil and takes up that worn slack. The 1 turn allows a margin of error greater than 0 lash or 1/4 turn does. As far as rpm's are concerned, I think as you increase the rpm's there is a little more 'play' in the valvetrain and it allows more oil to enter the lifter which causes the valve to be open a hair when it should be closed, hence the term 'pump up'. Really you could set them just like a mech lifter but they are not made to have the pushrod seat ram into the retaining clip or the extra oil pressure which can cause lifter failure. I guess the anti-pump up, or fast bleed, lifters do not allow that extra oil to enter the lifter so you get no 'pump up' affect. Not sure if those are made to have zero lash or not, I would give the 1/4 turn myself. Now his is my own observation on lifters but may not be 100% accurate. But what in life is?
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From: Waterloo ontario Canada
Re: valve adjustment with rollers??? (dash8)
I do not have luck twisting the push rod to find zero lash. I move the push rod up and down vertically while slowly tightening the rocker arm. When all up and down movement stops I give it an extra 3/4 turn.
A hydraulic lifter has a small plunger inside or floating piston. If the valve is adjusted so the piston is hitting the bottom the valve is held off the seat and the lifter can't cushion the shock of loading and unloading. If the piston is not pushed down far enough it clatters and once again a shock load if felt by the lifter. You are trying to get this piston that is pushed up by oil pressure to float between bottoming and topping out.
A header leak will sound just like a bad lifter. The two can be confussing to tell the difference.
Good luck
A hydraulic lifter has a small plunger inside or floating piston. If the valve is adjusted so the piston is hitting the bottom the valve is held off the seat and the lifter can't cushion the shock of loading and unloading. If the piston is not pushed down far enough it clatters and once again a shock load if felt by the lifter. You are trying to get this piston that is pushed up by oil pressure to float between bottoming and topping out.
A header leak will sound just like a bad lifter. The two can be confussing to tell the difference.
Good luck
