electronic PCV system?

[Import Power]

Originally Posted by FaceGarden

This is all starting to sound like a really good idea... one of those mods everyone is going to want to do... This seems especially great for a tired old engine, righ?

So how should it go?
Crank Case-----> Catch Can -----> Vac Pump ----> Atmosphere?
not so sure if we'd want to vent the pump to the atmosphere, but where else would we vent it? I might go ahead and try this out... Are there any risks?
-Taylor

I thought it would go like this (please correct if wrong)

Crank Case-----> Vac Pump (pulling from Crank Case and pushing into Catch Can -----> Catch Can (has filter for release to atmosphere)----> Atmosphere

[Eric_VR-4]

I think the catch can should go in front of the pump.. since it wasn't designed for oil vapor we might want to keep as much of it out of there... but either way would work.. slightly better vacuum your way IPO it would seem

[Import Power]

actually it does still act like a spring. I have read so much on this lately
Excessive Crank pressure impedes the movement of the piston. Relieving it frees up power. Plus helps with blow by, oil in combustion chamber.

Too much vacuum, you are correct, it can and will pull too much oil out of where it belongs. A simple Needle valve placed in line fixes that.

[Eric_VR-4]

needle valve is a good idea.. I wonder how we would know if we needed it though

[Import Power]

Originally Posted by Eric_VR-4

needle valve is a good idea.. I wonder how we would know if we needed it though

Too much oil in catch can?

[Eric_VR-4]

what is too much? Just trying to learn here

[doctorstupid]

Originally Posted by Import Power

Actually NO.

"ProStock cars use electric pumps. NHRA realizes the added HP potential and ruled that Stock Eliminator can’t use anything other than a PCV valve and SuperStock is only allowed to use the exhaust evac system."

Realize this:
To make power the piston has to be forced down by the combustion event. Imagine a large spring underneath the piston which tries to keep the piston from moving down. This is what positive crankcase pressure does. It is a large resistance force against the piston's downward movement. Remove this force and you free up HP. It's very simple. Known fact, and in FI cars is even more critical.

Well yes, I understand that. But seriously, 40 wheel horsepower? That's a lot of power...


I am really liking the idea of this pump, and don't get me worng, I won't complain if I pick up 40AWHP, but I'm not holding my breath

[doctorstupid]

Originally Posted by FaceGarden

I just realized that the volume of air underneath the pistons should never change... as one moves down, another one moves up, so the air is just being moved, but never compressed... Therefore the air is not acting like a spring, just some light mass to move. Adding a vacuum would still help pull the piston down, but like I said I'm not sure if that would help since another piston would be fighting to move up at the same time.

A spring isn't the best analogy for what's happening, what we're trying to avoid is crankcase PRESSURE, meaning the gases in the crankcase will be pushing equaly in all directions. As you pointed out, the crancase volume doesn't change, but the pressurized air is still pushing up on the pistons. If there's 10PSIg in the crankcase, that equates to 101 pounds acting upwards on all the pistons (assuming stock bore).

I have no idea if 10PSIg is realistic or not, just an example

[Eric_VR-4]

wow.. math is kewl
I'm definitely going to hook up a boost/vacuum meter to the crankcase as well

something just occurred to me though. Yes you have this force pushing up on pistons trying to come down.. but it is simultaneously pushing on the ones on their way back up.. so maybe it is merely removing some of the air resistance.. rather than a pressure thing

[Import Power]

And from what I have read, FI applications need it more than NA and get more Power from it than NA.