Rocker to valve settings problems

[George R.]

I've been having problems with my L71 rocker arms lash backing off so i doubled up on the rocker nuts and it seemed to cure the problem. Anyone else ever try this? Using stock stamped rockers w/ stock mech-cam. All my threads are in good shape in the heads.

[Joe L.]

Re: Rocker to valve settings problems

George-----

All of the threads on the rocker studs may be in good shape but I expect that the self-locking nuts are worn and no longer capable of maintaining their set. What you've done is installed a lock nut to keep them in place. That will work, but I don't recommend it as anything more than a temporary solution. The best solution is to install new lock nuts. New ones are still available under the original part number of GM #3896648 for a current GM list price of $1.67/each.

[George R.]

Re: Rocker to valve settings problems

Thanks Joe. I thought the GM nuts were o.k. but then again how many times can you back them off completely and reinstall/reset them to specs. Your right on Joe they have lost there fit.

My old 70 Z/28 had a set of after market stamped rockers w/roller tips (early 90's) and they could only take one installation. After a removal/reinstallation there was always a couple that would just come loose within a couple miles everytime.

Thanks again.

[Joe L.]

Re: Rocker to valve settings problems

George-----

The self-locking nuts used on Chevrolet V-8 engines are a very life-limited component when used on engines with mechanical lifters. On hydraulic lifter engines, which includes the vast majority ot the engines out there, they may last "forever" since the wear on the nuts only occurs when they are turned. With hydraulic lifters, they rarely need to be turned. Even on hydraulic lifter engines, though, the nuts should always be replaced at rebuild time. Many are not, however.

[frank mccracken]

Re: Rocker to valve settings problems

Are the studs pulling out?

[John H.]

Re: Rocker to valve settings problems

They're screw-in studs.

[frank mccracken]

Re: Rocker to valve settings problems

Are all solid lifter engines screw in studs? Could the heads have been replaced with press in stud heads?

[frank mccracken]

Re: Rocker to valve settings problems

O I get it [I had to be advised] L71 not LT1. :-)