what happens with over-lash?
08-25-2007, 07:42 PM
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Car: 1983 z-28/SFC/bilsteins/adj.arms
Engine: 355sbc/Demon650dp/hedmanheaders/
Transmission: t-5, alum DS
Axle/Gears: 3.42 torsen posi, baer discs
what happens with over-lash?
does anyone know if you happen to over-tighten the lash on hydraulic roller lifters? could anything bad happen? when the lash is correct, can you still rotate the pushrod? i'm not sure i know what to look for...when i tighten the nut until there is no play, then tighten 3/4 turn and lock.....after i run the engine a bit and look at the pushrods...i can still rotate the pushrod! is this normal? i'm running self-aligning full roller rockers....
Last edited by wdigitog; 08-25-2007 at 07:49 PM.
08-25-2007, 08:29 PM
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Car: 1988 Trans Am GTA
Engine: 350 4BBL
Transmission: 700R4
Axle/Gears: 3.27
Re: what happens with over-lash?
does anyone know if you happen to over-tighten the lash on hydraulic roller lifters? could anything bad happen? when the lash is correct, can you still rotate the pushrod? i'm not sure i know what to look for...when i tighten the nut until there is no play, then tighten 3/4 turn and lock.....after i run the engine a bit and look at the pushrods...i can still rotate the pushrod! is this normal? i'm running self-aligning full roller rockers....
It is normal for the pushrods to be easy enough to rotate after the engine has been shut off for a while and there is no oil pressure.
When they are talking about rotating them, they mean like spinning a pencil with the point down on a table standing up. That loose.
If the engine has been shut of for a while and the valves are closed you can rotate the pushrods like unscrewing a bolt that is finger tight.
Easy to demonstrate, hard to put into words.
08-26-2007, 06:53 AM
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Car: 1983 z-28/SFC/bilsteins/adj.arms
Engine: 355sbc/Demon650dp/hedmanheaders/
Transmission: t-5, alum DS
Axle/Gears: 3.42 torsen posi, baer discs
Re: what happens with over-lash?
so it's ok? i just find it hard to install the rockers with the engine already installed in the car. you have to "bump" the motor constantly to get the lifter on the cam base for each cylinder...very time consuming. i tend to "eyeball" the rockers to see when they're at the top (valve seated) of their travel. so, can a over tight lash make a car run rough? i was thinking that added pressure on the cam might add strain to the engine. i thought my engine ran very smoothly until i started tightening the rocker nuts.....i'm gonna loosen the ones i tightened and see what happens...
Last edited by wdigitog; 08-26-2007 at 07:00 AM.
08-26-2007, 07:42 AM
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Re: what happens with over-lash?
When you tighten them down snug the rocker nuts up just to the point where you feel tension on the pushrod. Use a feeler gauge if you have one that is the best way to set the lash, and no nothing bad will happen if the valves aren't in adjustment it will just make some valve noise which is annoying but not hurting anything.
