Valve lash

[71VERT]

Hi folks,
I am installing new umbrella seals in the car this weekend ( 1971 350/270 ) How do adjust the valve lash?
Is this just how hard you tighten down the rocker nuts? I haven't worked on an engine since my younger years.

Also is it worth installing new roller rockers while I have the valve covers off. And are there roller rockers I can install without making any additional mods.

Thanks

Jerry

 

[JohnZ]

With your hydraulic-lifter engine, you can set them cold; set it at #1 TDC and set:

Intakes 1-2-5-7, Exhausts 1-3-4-8

Turn it one revolution (360 degrees) and set:

Intakes 3-4-6-8, Exhausts 2-5-6-7

Just loosen the rocker nuts until you feel up-down play in the pushrod, tighten slowly until the play is gone, and tighten the nut 1/2-turn to center the plunger in the lifter.

I don't know of any full-roller rockers that will fit under your stock valve covers (without machining the tops of the poly-lock nuts); the Comp Cams Magnum roller-tip rockers will fit, as they use stock-type nuts.

 

[JHL]

Here is a link to a tech article from Chevy High Performance which details the procedure with some nice pictures as well.

J.

Setting Valve Lash