Crane Cams Adjustable Vacuum Advance kit

[Tobias]

I recently bought and fitted a Crane Cams adjustable vacuum advance kit (Part No. CRN-99600-1) to assist with tuning my 350 SBC (Edelbrock Performer Series 600 CFM, 'sensible' road cam and GM HEI distributor).

The installation instructions that came with the adjustable vacuum advance kit state that you should begin with the adjustment wound fully in (i.e. turn the hexagon wrench to the maximum clockwise position).

Question: What instructions don't say (and I can't find anywhere) is whether this position provides MORE or LESS vacuum advance. Anyone used this kit before, or know the answer?

Thanks.

[mr0077]

Tobias, what do the instructions say after that? I haven't used that particular product, but I would expect to start out "failsafe", that is, with minimum additional advance, so the full CW position would provide less advance...it would lock out the vacuujm advace I think. If so, the instructions would then say something about how to adjust it, like "test drive the car in a higher gear, applying throttle quickly under various load conditions; if no pinging is heard, turn the adjusting screw CCW 1/2 turn (or 1 turn, or some amount) and test drive again; continue until light pinging is heard, then turn the adjuster CW 1/4 turn (or some amount) until pinging is not heard under any load or condition".
That procedure is typically done in a higher gear at a "low" RPM, probably 4th gear at maybe 2000-3000 RPM.

[Tobias]

Ken. Thanks for that. yes - the instructions say almost word for word what you suggest below, so it must be that the start point (fully wound in) is the minimum vacuum advance setting.

I'm going to try setting the initial advance to 15º this week (it's at 8º at the moment) and then play with the adjustable vacuum advance.

Will post here to let you know how I got on. Once again, thanks.