blau928

Hi Sharksters,

I am curious to know if any of you are running a Vacuum Pump on your modified 32V cars. I am thinking of installing one, and wanted to get comments from anyone who has already done so..

What type of VP?

How much Vac is it pulling at max Rpm?

Any before/after dyno runs to compare?

Real plus if you have done this mod and your car has an iron lung or the like..

I have attached a pic of a VP that I think can fit where the current airpump lives..

Smog won't be an issue for me, my techs are very friendly to me...!

Thanks,

BC

That one looks nice and compact. I will be installing one with my V-1.

blau928

Brendan,

It's about 5" X 5" in size, very similar to the airpump..

Anyone else at least thinking about this....? Especially all the boost freaks with those catch cans that have to be drained all the time...

Hmmmmmmmmmmmm...............................................?

Professor Louis....?

BC

Is this the one that Porken mentioned? Is this one okay with the oil mist? I would assume it has to be separated before the pump?

blau928

Brendan,

This pump needs oil to lubricate the wipers... The separator is placed after this pump...

BC

I like that. Though with some engines you may need a pre-seperator as well.

FlyingDog

Dry sump.

PorKen

(Here's) the last thread where I asked the same question.

Here's some good articles on the GZ pump:

DRO Tech Section - Power from Thin Air - 1-7-05
DRO Tech Section - Power from Thin Air Part 2 - 2-9-05

To keep the pumps happy on the street, they use a separator which always drains some oil back into the pump feed line.

BC

The thing is that I hooked the air pump up directly to the top of the seperator on the early canister style cars. No other way for air to get IN the engine. There was a plate I installed at the base of that canisteroil fill separator thing and it was drilled on the non-direct side to let air through but not as much oil.

The thing pumped about 2 quarts up and into the air pump in about 5 minutes. Puddles of it were comming out the exhaust of the ait pump.

That second article mentions to have NO WAY for air to seep INTO the crank case. How are they not simply pumping oil up into the heads and into the pump?

Is the 928 engine THAT BAD at crank case oil control? Or so I just continuously get this**** wrong?

PorKen

Perhaps the lower drain hose to the crankcase was the problem? With the restrictor plate, the pump may have been pulling and/or oil may have been pushed by blowby up the drain pipe*.

I'm going to block off the pipe with the factory plate when I ditch the separator tower.
__________________
*The bottom of which is under the top of the oil level.

FlyingDog

That's probably the problem.

BC

I was only pulling from the top of the oil filler cap.

blau928

My theory:

Attach the VP before the A/O separator.. The oil drain then goes from the separator to the sump, or possibly the Valve Covers... Air gets vented into ATM, past the cats into the exhaust, or into the Intake of the SC (pre Filter) as it should be relatively clean.

I also plan on using a Vacuum valve/limiter so as not to suck up too much oil into the pump.

The point of evac from the engine will be at the oil filler area on the block just behind the Water bridge..

On another note, the SC will be fed pressurized oil from the engine oil line, and drain to the sump or the Valve Covers...

Comments...?

Louie928

Yup. I've thought about it and Ken (porken) has done some digging on vacuum pumps too. Mike Schmidt used the regular smog pump and was able to pull measureable vacuum in the (S4) crankcase and did see a few hp gain on the dyno. The vanes in the pump didn't last very long. My plan was to check into replacing the stock pump vanes with teflon and see what happens. I haven't even got as far as taking a stock pump apart to check that for feasability yet. The cost of these GZ pumps is high enough where I don't want to spend that many $$ on an experiment. As for gaining an extra 30hp or thereabouts, I doubt that will happen. Possibly less oil foaming and better oil control is my hoped for result. I'd be happy to see 5 hp gain. The 928 oil sump is way too shallow and just about any sloshing will cause oil to be hit by the crank. The overall breather system is horrible at best. There is not enough venting capacity in the 32v crankcase so nearly all of the blowby has to exit up through the oil drainback passages from the head to be vented out the cam covers. The easiest almost fix is to install vents in the left side cam cover GTS style which will split the blow up into two sides rather than only the right side. Dave Roberts has a kit for this.

I checked with Moroso and probably other vacuum pump manufacturers and found none who recommended their pumps for street use. Apparently in drag engine use they don't last very long and need rebuilt every 10 runs or so. These GZ pumps are the only ones I've seen that are recommended for street use. Who will be first to dig deep and try one of these?

blau928

Louie,

If I rig it up as described, will it work..? I am not looking for 30HP, just oil control, as I will be going above atmospheric on the intake.....