smog pump to decrease crankcase pressure

[EclipseTurbo]

I need help. I read all over the web about using vacuum pumps to pull as much as 15 inHG of vacuum and claims of more horsepower. (30HP??)

But I can not find any implications of doing this on a forced induction engine.

Has anyone done this on their turbo cars?

mainly I would like to install GM smog pump and powered only when WOT. I just have a "passive" breather hose right now and it appears to be not enough.. = oil going out places it shouldn't be. I am not really looking for HP gain at all but reduce my crankcase pressure. But I don't want to do things wrong and lose power or causing oiling problems.

Any advice on this subject would be appreciated

I have a LT1 electric pump on the way and I was told it pulls 25inHg. This sounds wrong. I may have to add resistor to decrease to a less vacuum if this is the case.

 

[bruce]

Originally posted by EclipseTurbo
I need help. I read all over the web about using vacuum pumps to pull as much as 15 inHG of vacuum and claims of more horsepower. (30HP??)

yes, lowering the crankcase pressure helps with ring seal. If there are many or much leakage, then it'll take alot of pump to actually draw any vac..

The electric smog pumps are only meant for a min or 2 duty cycle. Running them too long shortens their life expectancy.

 

[EclipseTurbo]

The way I understand it is the ring can leak the most in top most or bottom most position..

but in a boosted engine isn't there already boost creating a large differential pressure to seal the ring?

 

[bruce]

Originally posted by EclipseTurbo
The way I understand it is the ring can leak the most in top most or bottom most position..
but in a boosted engine isn't there already boost creating a large differential pressure to seal the ring?

Max cylinder pressure happens at like 8-12d ATDC, and the piston is trying to rock at that stage. With the side thrust on the piston, it just has to force the rings into a slightly cocked position. Anything that can be done to aid in their sealing is going to min blow-by. Trouble is what's really an effective answer for a given application.

IMO, the reason gapless rings work, is that they allow for 2 ring sealing points instead of one, rather then they don't have a large single gap. But, hey, I'm no ME.