Has anyone ever considered using a vacuum pump on their high performance engine? It seems that a lot of more radically engineered engines are doing this for some benefits in power and improved oiling.

There are few ways this is being done in VW's that I have read about. They are mechanical or electric pump, or by a velocity-extraction pipe welded into the exhaust header (which only works at higher rpms).

From what Ive read there are quite a few advantages.
- Reduced oil leaks (good in vw's)
- Less pressure on the bottom of the pistons on the down strokes(less horsepower loss)
- Reduced oil foaming

any thoughts?

I can see it would reduce oil leaks, basically cos it is sucking up the blow by before it can make any crank case pressure.

I think it would increase oil consumption because it would suck out the oil/air mist before it had a chance to seperate out.

I woulda thought the HP increase would be almost unmeasurable.

I think it may help cooling as blow by is extremely hot and heats the oil. It is the reason older engines run hotter (more blowby heating the oil)

I would install a sand seal on the crank pulley before trying to run this set-up, otherwise you would suck crap in though the oil slinger threads.

That's my thoughts...

In High Performance applications they produce a significant increase in HP due to decrease in windage - a Group A engine will lose about 40HP without it! I think for most applications on the beetle the drag of the pump (it's a crank-driven pump) would outweigh any benifits.

If I were doing it I would go for the scavenger in the exhaust after the collector system.
Just as the stinger or tail pipe expands after the collector.