vacuum pump help

[prairiehotrodder]

Just installed a product engineering vacuum pump on my 555 BBC. Wondering what vacuum i should expect to see. I have 18 tooth crank gear and 32 tooth on the pump. The 18 tooth was the smallest they make. At idle 1000 rpm i'm getting about 1.5 to 2 inches of vacuum checking on the opposite valve cover. Rev it up to about 2500 rpm and its at about 9 inches.

EDIT: i see a 17 tooth gear is available.

EDIT: this is without a regulator. I have one i could install but wasn't sure it was needed.

[steve cowan]

Brian ,
You just have to try it I guess, wide open throttle may show more than 9" vac.
As far as what your combination needs?
Have to test

[rebelrouser]

Just a couple observations after messing with the vacuum pump on my engine. One of the factors will be how much blow=by your rings have the more blow-by the less vacuum your pump will make, as it has to constantly keep up with the leakage past the rings. secondly how well is your engine crankcase sealed up. I used an automotive type smoke machine to check my engine on the stand, it showed a couple small leaks that since you have a pump, one of the benefits is no oil leaks, so if you have small leaks they become hard to find. I found one of the rear main seals that has a double lip designed for vacuum pumps is a benefit as well. You can look in the archives, but many say above 10 inches you may pull the oil out of the wrist pins. I have seen engines that pulled more and had no issues, but trial and error could get expensive. Mine hold 1.5 to 2 at idle and about 6 to 8 going down the track, don't remember to look at the gauge to tell you the truth.

[prairiehotrodder]

Took it for a drive today. In 1st gear slowly accelerated up to 5500 - 6000 rpm. The vacuum never went past 10. I know this isn't to scientific but its kind of a hard thing to check before you get to the track. One handy thing is that i have a AEM failsafe gage that data logs AFR / RPM / Vac. So I just unhooked the hose from the intake manifold vacuum and hooked it up to crankcase vacuum. Then when i make a pass i can check my datalogging and see what happened. i'm thinking my engine probably has a fair amount of blowby because of my less than professional extra - safe ring gapping skills. I know on a pass it would push the dipstick out a couple inches and blow oil all over the place. Hopefully this vacuum system stops that from happening again. I tried to gear the pump on the conservative side. I watched a youtube video where a 1050 hp 582 gained 52 hp with a vacuum pump. If I gained 25 I would be real happy. Maybe just enough to put my car into an 8 second timeslip to hang on the wall. Best so far is 9.17.
Brian

[prairiehotrodder]

Anyone use the aeromotive 33101 vacuum regulator ? I have one but i'm not really sure how to use it. I can't seem to find any instructions for it anywhere.

According to my tiny brain, the pulley sizes shouldn't control the total vacuum that the pump can achieve. They just control the RPM at which it is reached. Is my thinking correct ?

Maybe i will install the regulator and try and set it on the conservative side, make a pass, check my data logging and adjust the regulator if i need to. I'm really scared to have to much vacuum on my first pass and damage my motor or suck oil and possibly spill on the track.

Brian

[cad]

https://www.jegs.com/InstallationInstru ... -33101.pdf