legacycentral bbs

Looking for an electric vacuum pump. something small i can wire into the car for pumping air (no liquids). Anyone know of one or have any leads on one?

what sort of flow capacity do you want? What you going to use it for?

Instead of just letting the PCV blow out the extra crankcase pressure, I intend to suck it out with a vacuum.

This leads to better ring seal and better compression.

I don't know how much vacuum i need. Maybe a way to find this would be to hook a pressure gauge up to the PCV valve? thoughts?

hmmm....that's interesting thought.

Not sure you would want a lot of differential though. Maybe 1-2 psi.

I'm still a little curious how you'd pull this off.....

Diesels. Many have vacuum pumps running everything on the engine.

Good idea, you could suck the crank and valve covers and at the same time keep the intake clean by venting to atmosphere!

you could technically do away with the entire PCV system if you had a vacuum pump couldn't you? You'd have to if you were to vent to atmosphere.

Yep. That's the theory. I haven't been able to find a pump from a diesel that was small in size enough.

Anyone with more diesel experience care to shed some light?

With all the small diesels in Europe, you may be able to find something from Britain (where they sort of speak the same language). A Peugeot, perhaps? Don't really know, but I would guess even with all the other modern features that they would still require a pump.

Steve

Volvo.

VW has also made Turbo Diesel's here for a long time. They'd probably use a smaller application motor like you're describing. It'd also be pretty easy to find in a junkyard.

-Brian

Four thoughts:

- You need to make sure your pump not only pulls an appropriate vacuum pressure but also that it can flow enough volume and can handle the compounds that are in the crankcase gases.

- Mercedes diesels have vacuum pumps as well; I don't know how big though. It shouldn't be too hard to find parts from a 300D or 240D.

- You may be able to adapt one of those cheap fill-your-tire-up-when-you're-stranded air compressors that are powered off the cigarette lighter. An air compressor has to be pulling its input from somewhere, and producing a partial vacuum there. Likewise, you could try a refrigerant compressor meant for a small refrigerator (you'll just have to figure out a way to power it) or even an air conditioning compressor for a car, if you want to run it off the crankshaft.

- Whatever pump you end up using, make sure you take care of any lubrication issues it may have. For example, the air conditioning compressors typically need some lubrication in the air they suck. Crankcase fumes may or may not be sufficient.

Jason,

Did you find any more info regarding this??

Most of the early euro diesels shared the same block more or less as their gas fueled cousins. At least with the VW's, they simply removed the distributor, and put in place a mechanical vacum pump.

Ive seen it on a couple american diesels too.

The 240D and 300D Mercedes pumps would be hard to get to work, as they actually are reciprocating instead of rotary.