Vacuum pumps

I have read that electric vacuum pumps, as used on some smalled GM cars have been adapted to create a negative pressure in some Hi-po engines and increase power. I understand that the pumps were used to assist the power brakes, etc. NAPA is supposed to stock the pump, but my local store counterman wasn't to successful in finding the number. Has anyone heard of this being done to an engine.
Vic

Sure. You also need a vacuum pump if you're running a Weber setup, since there is no vacuum source on the intake.

I came up with the following list of possible candidates when I was looking into it:

Ford part #F81Z-2A451-BA (from F350 diesel pickup)

GM part #22034995

MP Brakes vacuum pump

Electro Automotive vacuum pump

SSBC vacuum pump

Haven't heard what Finish Line decided to use on my car yet...

There are some vacuum pump setups in the Summit catalog; evidently running an engine with less-than-ambient pressure in the crankcase improves performance. Whether it improves it enough to justify the cost in our applications I don't know.
Also, the Weber manifold/carburetor kits from Pierce Manifolds have vacuum 'outlets'
(inlets?) on them, which can be used for vacuum advance or power accessories. I don't think a GT40 needs power brakes, the windscreen wipers are electric, and I haven't seen any vacuum advance distributors, so I am not clear on what the vacuum would be used to do.

Jim,

The CAV has a vacuum brake booster and comes wired from the factory for an electric vacuum pump. The pumps in the Summit catalog are not suitable for running the brake booster, but are as you pointed out for crankcase evac use.

I was interested in using the pump as a PCV system and pump the gasses into one of the headers.
VIC

Just how a radical a cam are you planning to run???

I don't think the production cars that are out there with electric vacuum pumps use them as a PVC system, but rather to supply an adequate vacuum source for brakes & accessories.

For your application, the ones listed in the Summit catalog would be appropriate (and then only if you have a cam that won't idle and won't pass a smog test), but I have no idea how much of a gain you can expect.