How noisy should the valve train be with CompCams Pro Mangnum 1.6 roller rockers. Mine are a little noisier than the stock rockers were. To the point that they can easily be heard with the hood shut while its running. They are not clicking like a loose rocker would be, but just that sewing machine kind of sound. Do yours sound like that?

How much pre load on the lifter??

Will

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What do you mean by pre-load? Do you mean how much past Zero lash? If that is what you mean, they only have about 1/8 to 1/4 turn past zero lash. This is where Lloyd Elliot told me to lock them down. I guess I could go to 1/2 easily, but I was following his suggestions.

Yes that is what pre load is.

At a 1/4 turn they should sound like you described. My T&D shaft mounts sound just as you described with 1/4 turn (which is about .020 lifter pre load).

Going to a 1/2 turn will quite them down some but it will also increase the chance that the lifter will "pump up" at higher RPM.

What lifters are you using?

The GM racing "Caddy" lifters recommend .040 pre load. I used them in an engine I recently built for Noland Smith (Black Harley Man on the CF) and his is as quite as a mouse at 1/4 turn and pulls to 7000rpm without any valve float or lifter pump.

I think you would be OK but every engine is different. Since he spec'd the cam for you, I would ask Llyod if going to 1/2 a turn would hurt you or not.
Will