boostd4

I've been searching for 30 minutes or so and come up with conflicting information.

ESPECIALLY how many turns past zero lash gives you acceptable lifter preload. Anywhere from 1/4 turn to 2 turns if you read all the search results.

Anyway, I have an adjustable PR checker and am trying to find out what length pushrods I need to buy to get my lifter preload to 0.080 - the goal is a quiet valvetrain that doesn't present any danger to the engine. FWIW, the car has stock 99 LS1 lifters and rocker arms.

If I can figure out what a single turn corresponds to in inches, there will be no more guessing.

... and to the nay-sayers - I have a dial indicator and used it for 3 or 4 cylinders, but some cylinders just don't have a way to get the needle in the right place with the lack of magnetic objects around. My indicator is VERY sensitve as well leading to inconsistant readings. I'd like to just be done with it, and since stock lifters are a bit more forgiving, I'm going to finish off with the turns-to-torqued method.

Anyone know the TPI?

vettenuts

iTrader: (4)

As I remember, the thread pitch is 1.25 mm. However, you don't need that if you have an adjustable pushrod. Just follow the procedure to measure. Using the thread pitch of the bolt has to be corrected for the rocker ratio too.

boostd4

The pushrod checker's instrutions say to adjust the PR up until zero leash and then add your desired lifter preload.

Unfortunately there's no way I can get my fingers in there to turn the adjust PR to raise it up to zero lash

vettenuts

iTrader: (4)

See if this helps: Link

boostd4

Thanks for that link. It's pretty much the same thing I'm doing without having to use the torque wrench (which can be a pain in tight places). I think I'll do the rest of the pushrod measurements like that, seems much easier.

My fingers are DEAD tired from screwing and unscrewing the damn rockers to change the adjustable pushrod... my brother stole my little snap-on electric screwdriver. He's a dead man.