valvetrain problem
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valvetrain problem
Been fighting a loosing battle with rocker/lifter knock. It's a lt1..30k on this motor..holds around 50psi oil pressure hot.
I've recently changed rocker arms and 4 lifters I thought was going bad. With the valve covers off you can hear it real good. It will get so loud sometimes,the knock sensor will pull max timing...10degrees...observed on data master.
I've been trying both ways to adjust rockers. With valve closed and tightening untill the pushrod stops turning..you can wait about 15 seconds and recheck and it's already loose. Just for the hell of it...I keep tightening untill I thought the rocker was bottomed out on the stud...still loosens up.
If doing it with engine running...adjusting all of one side....adjust untill knocking stops,you can let it run about a minute and they go back to knocking..go back tightening some more..knocking returns. I used a piece of air hose and listened..by placing on top of rocker stud. Can hear some louder than the others..but still a noise. I have a set of scorpion 1.6's...I even put my old set of the summit brand on...same thing. The 4 lifters I replaced are comps..they look just like whats in the others. So should I replace all of them?
I've recently changed rocker arms and 4 lifters I thought was going bad. With the valve covers off you can hear it real good. It will get so loud sometimes,the knock sensor will pull max timing...10degrees...observed on data master.
I've been trying both ways to adjust rockers. With valve closed and tightening untill the pushrod stops turning..you can wait about 15 seconds and recheck and it's already loose. Just for the hell of it...I keep tightening untill I thought the rocker was bottomed out on the stud...still loosens up.
If doing it with engine running...adjusting all of one side....adjust untill knocking stops,you can let it run about a minute and they go back to knocking..go back tightening some more..knocking returns. I used a piece of air hose and listened..by placing on top of rocker stud. Can hear some louder than the others..but still a noise. I have a set of scorpion 1.6's...I even put my old set of the summit brand on...same thing. The 4 lifters I replaced are comps..they look just like whats in the others. So should I replace all of them?
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Joined: Jun 2003
Posts: 1,112
Re: valvetrain problem
you do not tighten rocker until you can't turn PR...WAY to tight
the lifter does bleed down after adjusting so they will get lose but once you start motor lifter pumps up.
you need to lash valve correctly. assuming you are on the base circle of cam with each valve as you adjust...you tighten poly lock with fingers until there is no UP/DOWN movement of PR, then 1/2 turn more on poly lock alan nut while holding the wrench on the poly lock
the lifter does bleed down after adjusting so they will get lose but once you start motor lifter pumps up.
you need to lash valve correctly. assuming you are on the base circle of cam with each valve as you adjust...you tighten poly lock with fingers until there is no UP/DOWN movement of PR, then 1/2 turn more on poly lock alan nut while holding the wrench on the poly lock
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Joined: May 2011
Posts: 71
Re: valvetrain problem
i know the method....just wanted to see how far it'd go. by doing what you said....when the car is off...i can pull a rocker off the valve stem. while running it clacks so bad...it pulls max timing. the knock count never stops climbing. i'm thinking about trying solid roller lifters...
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Posts: 71
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