[Diy_efi] Good air pump for crankcase circulation?

[Phil]

Dereck-

<<Also there is the concern that on wet sump cars (mine included), you are
reducing the very pressure that pushes oil into the pickup, and are
reducing your oil pressure with every 1" of vacuum you pull.>>

What??? With all do respect, whoever gave this explanation of oil
pressure/crankcase ventilation relationship to you should be flogged, as it
is completely backwards. I've successfully built a number of 8200 RPM, 730+
HP, 540 ci. BBC's for drag racing and all of them had Stef's Vacuum Pumps
on them that pulled a regulated 19" of crankcase vacuum. Absolutely none of
them EVER had an oiling problem, all were wet sump and all lived healthy
lives at the strip. You might want to rethink this line of reasoning. =)

<<I'm just looking for a way of sucking gases out of the crankcase,>>

See above. ^^^

<<or maybe blowing fresh air in, to keep all the blow-by exhaust gases out
and any moisture I build up during my shots of methanol injection.>>

Again....what??? Blow fresh air in?? Use a Speed-Pro top ring and a Total
Seal second ring and you'll have no problems with excessive blow-by.
(providing the cylinders receive the proper finish) Any engine is going to
collect a small amount of condensation on the internal surfaces of the
cylinder case and cylinder heads..unless of course you never shut the
engine off...... =) Even race prepped engines sweat internally somewhat.
Engine oil has that task of removing the majority of the condensate that is
present and we have the task of changing the oil periodically. One hand
washes the other.

<<I don't want to use a PCV system, as I'll end up coating the inside of my
sparking clean turbo, intercooler, and intake manifold.>>

Not if it is plumbed correctly. Been there, done that.

<<I have yet to see a PCV implementation that didn't cause build up in the
motor.>>

Then you need to take a closer look at the successful PCV systems that were
utilized on the early Callaway TT'd L-98's and the LPE TT'd LS1's. We were
making some serious power with the LPE TT'd LS1 engines and NONE of them
exhibited oil intrusion into the positive pressure side of the compressor.
It can be accomplished with a little forethought and engineering. =)

I apologize if I come across as cynical, because that was not my intent,
but I wanted to present you with this correct information so that you may
be able to better make an informed decision on what path you choose.
Shannon's idea works very well also and racers have been successfully doing
it for years. =)

EFI content: If you choose the header evacuation route, mount the oxygen
sensor pre-evac plumbing.

HTH


-Phil





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