GeorgeC

I was checking out some pics of your car from the link in your .sig. What kind of drive are you using for your Moroso vacuum pump? It looks like a mandrel drive attached to the crank pulley. Did you fabricate this piece, or is a near-bolt on drive available somewhere?

I've been comtemplating ways to drive a mechanical pump, but you seem to have figured it out. I'd rather go that route than trying to rig up a modified electrical pump.

Thanks...

The BeaSSt

iTrader: (1)

It is a custom made mandrel, we could not find anything that just bolted up so we had to fab one. The pump is a 3 vane and it is adjusted via a poppoff valve on the driver side valve cover. We just finished this up and still have to put a gauge on it. There is also a baffle welded inside the pass. valve cover so as not to starve the valvetrain. We have not had a chance to do any dyno pulls with it yet, probably this weekend we will do a couple of pulls with & without the belt. I was waiting to post untill I had some better pics & accurate results. I will keep you posted.

Dave

GeorgeC

Thanks Dave, I figured it was something custom. Doesn't look all that difficult to fab up though. I currently run a generic header mounted evac system, which actually works pretty well when the mufflers are off. I usually pick up .07-.08sec and ~1mph by dropping the mufflers (Flowmaster 1 chambers), most of which I account to the evac system actually working.

I tried making baffles in my stock valve covers, but finally wound up just using the valve cover mounted chrome Mr. Gasket breathers, which seem to work well.

Maybe I'll play around and see if I can work up a mandrel drive similar to yours, and just go with the mechanical 3-vane pump instead of messing with an electrical setup.

Thanks...

The BeaSSt

iTrader: (1)

Hey George, the old timers tell me they would install the main seals in reverse to take full advantage of the pump. Have you ever heard of this?

Thanks
Dave

Silver Pig

Dont know about turning the rear main around backwards at all. I guess it would work under vacuum but if your vacuum pumped failed for whatever reason be looking for a huge leak!

Sean(Pig)

jmX

With my vacuum pump off I see 2psi of crankcase boost at 6800rpms....doesnt seem like that'd be enough to screw up any seals.

GeorgeC

Never heard anything about installing any seals in reverse... Sounds strange to me.

jmX: I remember you doing up some kind of evacuation setup awhile back and having mixed results. What are you using now? I really want to get away from my header mounted system.