62 327/340hp Valve Lash 30/30 Cam

[Tom C.]

I just read with interest an article published by John Hinckney and Duke Williams concerning valve lash on the 30/30 high lift mechanican cams. Their recommendation for a cold lash was to go 90 degrees BEYOND TDC in order to insure that the lifter was on the "circle" of the lobe and not the "ramp".

1. I wonder if this same proceedure would apply to the 327/340hp engine with mechanical cam. Or will the traditional TDC and 180 degree rotation work well enough for a cold lash. Tuneup specifications for my engine call for a (hot lash) .008 intake and .018 exhaust.

2. Does anyone know what the cold lash values for the 327/340 should be? I am sorry but I do not know the specifications of my cam. It is the original solid lifter cam which came with the 327/340 hp engine.

[Duke W.]

Re: 62 327/340hp Valve Lash 30/30 Cam

The paper explains in great detail all the whys and wherefores for all SB mechanical lifter cams including the 3736097 "Duntov cam" that was OE on the 327/340. The 3849346 "30-30 cam" replaced the 097 in 1964. John wrote page 1 specifically for the 30-30 cam, and I added page two to cover the other SB mechanical lifter cams.

The lastest revision (annotated on Page 2) is 12/05. If you do not have this version, e-mail me, and I will send it to you.

Old versions are posted on some web sites, and the recommended lash settings have been changed based on my analysis of the detailed lobe data from the engineering drawings.

The original recommended settings were based on my analysis of lift-crank angle diagrams, which is no where near as accurate as using the actual design data.

Duke