1995 5.7 GMC Suburban

[Suburban Guy]

Just finished a new motor install and have replaced the cam shaft with a Comp Cams camshaft, lifters and springs. I zero'd the lash then went an additional 3/4 turn.

At idle everything is nice a quiet but run it up to 2500 rpm and I can detect what I think is some rocker arm noise. The old motor didn't have this noise so I'm fairly convinced I haven't got the valve lash set exactly right.

 

Is there a break in period where I should expect a little extra noise or?? I'm going to call Comp Cams too but I wanted to post it here and see what input I would get.

 

Thanks,

 

SG

[I-H8-4Ds]

With a standard cam, the procedure was to take it down to xero lash, then give it one additional turn.

 

What did comp cams have to say?

[Suburban Guy]

Manual say zero lash then 3/4 turn.

Comp Cams instructions say zero lash then 1/2 turn.

Comp Cams help desk says zero lash and then between 1/4 to 3/4 turn.

They went on to say that due to the lobe ramp that this cam will generate a slight "sewing machine" sound, which is exactly what I am hearing. I've re-adjusted the valve lash twice with the same result so I'm convinced that this is the way it's going to be. Any thoughts?

 

SG