BB vacuum pump kit choice?

Which kit would you recommend, price and quality concerned.
And which not?

Star or GZ

GZ was complete fits well on mine. Competitively priced.Good guy to deal with.
Doug

Moroso (4) Vane

I have a used enhanced GZ on the race car now, it didn't pull much vacuum ,5.0 or less : on the old motor
I have both a 3 and 4 vane used Moroso pumps that I will try this year on the new motor that is built for a vacuum pump, I'll post my results as they happen

I have a Moroso 4 Vane enhanced, pulls 7 in/hg at idle and 12 over 3000rpm though after some research I may set it to pull a little more.

A big factor in how much vacuum you can pull is how well the engine is sealed. I haven't tried reversing it yet but the rear main seal installed in it's normal orientation appears to be a big leak path. There is a double lip seal available as well.
Doug

I have the 4 vane Moroso on the hemi in the cuda and an older 3 vane Moroso on the Camaro and they work great. I used to run an Aerospace Components pump and it was complete JUNK.

Heard nothing but good things about the GZ and Star pumps.

Moroso 3 Vane on the dragster pulls 10 at idle and 14 down track, no regulator. My car has an enhanced 4 vane and pulls 10 or so at idle and 17-18 top end, not regulated. My experience sealing the engine is the key.

Al do you install the rear main seal backward?
Doug

My motor pulls 9-10" at the beginning of the run and 15.2" ish is what the regulator stops it at. I run a GZ pump and my crank seal is installed the conventional way.

Moroso 4 vane w/ reg (that I have wide open)

Doug, no my rear main seal is in the standard direction. I don't use a regulator on any of my stuff, just never been able to pull enough vacuum to worry about it.

I have a Star. I believed the hype and bought what I thought was the best option even though it was way more expensive than the others. I also bought the fancy separated catch can. Now to be fair my motor is not optimized for a vaccum pump but I get next to no vaccumm. I have the releif valve screwed in all the way and get 0 at idle and maybe 3 pounds going down the track. Plus as an added bonus it will fill up the puke tank and then spray oil all over my engine bay including my ceramic coated fenderwell headers. It is now collecting dust under my work bench and the old school pan evacs went back on! Now in fairness to Star my buddy has one on his Pontiac and thinks its the cats meow!!!!!

You are pulling air in somewhere. That will fill the tank, unless your pick up point is in liquid. Fab an adapter and put 3-4 psi in the crankcase. Then spray the motor with soapy water solution. My bet is you'll see bubbles.
Doug

Hey Doug!

Thank you for the advice. I was thinking the exact same thing. The pick up is in the front of the driver side valve cover. It is the fitting that star provides with the kit. The opening is currently facing down. I was thinking about facing it up and then retrying it.

With regards to pressuring up the motor. I actually put a valve stem in my valve cover for that exact purpose. However, when I checked it last I pulled the motor out of the car and I borrowed my buddies smoker. When we smoked it the smoke was coming out of the rear main seal area. I pulled the pan and redid the side seals and coated it with silicone. It still leaked a little around the seal but it was better. I was hoping when it was running it would seal a little better. But now that you mention it it took a while after doing that to fill the puke tank the first time. I bet a new leak has sprung up. I guess I have a little work to do.

another area to leak on a big block is the stock timing cover crank seal. IF you notice all the big blocks in this thread that pull over 10" have a jesel belt drive. That has a way better crank seal than the stock type. There are better crank seals to buy though.

Also with the Star pump, they don't like ANY oil in them. Try brake cleaning your pump by spraying brake clean into it while the engine is idling.


Call Star, they are helpful too and will walk you through what your doing wrong. They are some of the best vac pumps out there