Blown Crank Case Vacuum ??

With a screw blown alcohol deal, has anyone had any success with drawing a vacuum (or coming close to zero) while under boost? Either with dry sump pumps, or vacuum pumps, or both?

Would be interested to hear more. Designing the ventillation circuits for mine right now, and am wondering whether to even consider vacuum under boost or whether to just give the crank case a big breath of outside fresh air at all times.

Thanks.

 

For What It's Worth . . . .

Raced with one of the top BFH guys for several years.

Worlds Quickest and Fastest Top Fuel Boat for way long time.

Not legal for cars (for sure) but we ran a venturi on the rear zoomie tube on each side of the motor and plumbed the valve cover breathers to it.

We were convinced that this negative pressure to the breather vents helped keep oil out of the combustion chamber and keep the detonation / "green tongue" effects to a minimum.

Maybe yes . . . , maybe no.

One thing is for sure, we did not have the crew folks to thrash between rounds and as it turned out, we did not need to.

Very fast and very safe . . . . . , always.

Take care, K