I was talking with comp cams about a new camshaft (full roller in a 71 block) and they said if I was daily driving I would have to check for valve lash at least every 5,000 miles...I didn't want to sound like a moron so I didn't ask

Thanks guys!

 

Honestly, those were the perfect people to ask since they are the experts. Valve lash is basically the gap between the top of the valve and the rocker arm. A solid lifter uses lash, hydraulic lifters really don't use lash per se' . This doesn't mean that it doesn't need to be checked however. Usually you set the lash at zero plus a 1/2 to 3/4 turn, and you're done. Intake lash is set when the exhaust valve opens and the exhaust lash is set when the intake valve closes (on that cylinder). Solid lifter engine's lash does need to be adjusted from time to time.

 

Pretty much what he said. Hydra lifters have pressure to take up the gap as the valvetrain wears. A solid or solid roller does not so you have to run lash. Basically when you buy a comp cams camshaft they give you a spec card that states the lash specs. Like my 12-771-8 solid roller cam is .016 intake and .018 exhaust. This is just the gap between the roller rocker and the valve stem tip.

According to the Comp Cams Tech I spoke to the use of stud girdles helps reduce the occurance of having to run lash. The tech I spoke to said he only does it 9000 miles or more when using girdles.

http://www.cranecams.com/?show=techarticle&id=2