crankcase vacuum pumps

[jeffro ra28]

A good crankcase vacum system causes a substantial reduction in windage drag.
With less air and other gases in the crankcase, the oil droplets have no medium in which to mix and tend to fall into the pan. The crankshaft throws and counterweights cut through air that is mich thinner and contains far fewer oil droplets.

As the pistons reciprocate, they move alot of air and gas back and forth in the crankcase. This pumping action draws off power and contributes to windage. By reducing the amount of gas in the crankase these symptoms are significantly reduced.

Another benifit is the improved oil control in the engine. Engine oil has very poor combustion characteristics. It reduces the octane rating of the fuel charge and soots up the combustion chambers. Vacuum in your crankcase helps keep the oil from passing the compression rings.

The recent trend in pro stock drag racing engines is to have as much as 24"-26" of vacum. But for more common going dry sumped engines around 18" 20".

Ways of acheving some vacum in the crankcase can be acheived by a few different methods. Although the only real method to acheive good amounts of vacum is with a well setup dry sump system or a external belt driven vacum pump.
Bernoulli effect rigged to your exhaust system, a dry sump pump(usually pulls vacum if the system is setup properly and pump is in good nic) or an external vacum pump.

P.S. nothing but an external vacum pump or dry sump system will pull enough vacum to see descent HP gains.

[JZA70 R]

no an electric vacuum pump is no good?