Just curious who all is running a vacumn pump and if so, what kind of gains did you see on the track if any, after adding the pump?

My motor has never really had great ring seal and with my recent switch to 4.56 gears my trap rpm is up around 7200 and is blowing oil out the valve cover breathers. Real messy. I'm counting on the pump to help clean-up my engine bay and hoping it will help ring seal and maybe see a performance gain.

TIA

John,

I run a GZ Motorsports vacuum pump setup.

http://www.gzmotorsports.com

The owner, Greg Zucco was very helpful when I was looking to purchase. The one I bought was previously calles the Sportsman Plus which is now the middle series called the Pro pump.

I got the pump, brackets, fasteners, two pulley drive mandrel, 5.5" pump pulley, fittings, hoses, billet bolt on breather, billet fill cap, Stef's puke/breather tank, belt, and McClintic relief valve for approx $750.

On my car, I'd say the pump setup was worth almost a tenth. I installed it mainly to try and dry up a nagging mysterious oil leak.

It's a good idea to plumb a vacuum gauge into the intake manifold back by the distributor. I have mine regulated to 12.5" max vacuum.

I highly recommend the GZ Motorsports vacuum pumps...great product and excellent customer support before and after the sale.

Todd,

I went with the Aerospace kit. It came complete with everything except the gauge. I was eyeballing everything yesterday and it looks like it will be a clean/simple install.

Do you see any problems with mounting the vacumn gauge to the rear/upper face of the valve cover (opposite cover from suction hose)?

A tenth would be great!!!!!!!!!

Thanks.

John - On a tired engine (about .010" - .011" piston clearance) with poor ring seal, we added a Moroso 4 vane pump and saw about .15 second and 2 mph (we were running 10.90s @ 124 after adding the pump). We pulled the vacuum from the front PS valve cover, had the relief valve at the rear DS valve cover and the gauge at the front DS. When we added the Racepak later, we plumbed the Racepak vacuum sensor into the rear of the intake valley.

John,

The problem with hooking the gauge line to the valve cover is the added hassle of needing to disconnect another line to remove the valve covers for valve adjustments. It will work there fine though.

Roger, you probably meant .15 in ET and now .015, right?

I agree with Todd that it could be a problem. We just left enough slack in the gauge line that we could lay the valve cover on the cowl (without disconnecting it) when setting the valves.

Todd - yes, .15 seconds (old age catching up with me again, I corrected the post).

Thanks for the feedback guys.

Where do you pull the vacumn from, the top of the cover or front face? The destructions recommend the front face to ensure a sufficient amount of oil gets drawn in to lube the pump. Seems like that may cause an excessive amount to be drawn in, especially on the wind down. These Pro-1's have pretty generous sized oil drain-backs so maybe its a non-issue.

John,

When I first built my 383 SBC, I was having the same issue with oil coming out of the valve cover breathers. I also assumed it was ring seal. I checked leakdown and only had ~2%.

My problem turned out to be that my AFR 220 heads had VERY small oil drainback holes. Even at idle an excessive amount of oil was collecting in the valve covers. I can only imagine what it looked like on a 7000 RPM - 1/4 mile pass.

I dropped the trans and installed oil restrictors. No more oil coming out of the valve covers. Oil wasn't being blown out the valve covers - the valve covers were overflowing!! May not be an issue for you if the Pro 1's have a larger drainback hole.

If you already have a breather hole in the top of one of your valve covers I would start with putting your vacuum source there and check the line to the inlet of the pump and your reservoir after you make a few passes. If it looks like the pump is not getting enough lube at that point you can add another hole to the front of your valve covers.

Be careful and creep up on your vacuum settings. Don't want to frag a pin.

P.S. - Got the rods back today. Unfortunately I won't be home until Fri. night to check them out. :(

couple of weeks ago went through a whole-day dyno session....vacuum pump added 15 HP...not sure what that would translate to ET at the track..

555 BBC, 15.1:1 CR, 4-vane moroso pump, pulling 12" of vacuum...vacuum is being pulled from the top front of passenger cover, regulator is on the rear top of driver cover, fitting for gauge is at the rear top of passenger cover...can't take more than 10 seconds to disconnect the hose from the fitting...

main reason that used the pump is because I used low tension rings..

also, put your vacuum draw fitting at the top of the cover if you can...if you put it in the front face of the cover you will get plenty of oil in deceleration...

Originally posted by JOHN WILSON:
...The destructions recommend the front face to ensure a sufficient amount of oil gets drawn in to lube the pump. Seems like that may cause an excessive amount to be drawn in, especially on the wind down...John - we had the opposite problem. We struggled getting baffles and filters to restrict the amount of oil getting to the pump (and the puke tank). I would reccommend the top rather than the front.

John - Regarding the amount of vacuum... we did fairly extensive testing with different levels of vacuum and diferent ring tensions. Using typical rods, pins and clearances, at 14" - 16" of vacuum we had pin galling. This went away if we kept the vacuum in the 10" - 12" range.

Unfortunately, the real power gains seem to come at the higher end (up to 18"). If you want to run those levels, you need to look at casidiam coated pins, increased pin clearance and beam drilled rods (forced pin oiling).

Originally posted by 383Malibu:
[QUOTE]Originally posted by JOHN WILSON:
[qb] John - we had the opposite problem. We struggled getting baffles and filters to restrict the amount of oil getting to the pump (and the puke tank). I would reccommend the top rather than the front. Roger- Thats exactly what I'm afraid of. Think I'll start off on top as has been suggested and see how it goes.

Casidium coatings ehh? You guys are getting serious with this stuff. :eek: Are ya'll using the coatings on the new motor? Pins & valves etc...?

10-12" is what I'm shooting for. I'm still playing with the 422 which is just a Eagle/JE rotating assembly, nothing special, so pin galling is definitely a concern.

Yanni- do you think the HP gains would be less evident on a fresh motor? A buddy that posts here (sheetmetal) runs a GZ pump on a fresh 383 with low tension rings and saw very little gains at 12".

Jason, good to here about the rods. Let me know how the intake ports finish out. 360 would be pretty stout for a little ole home port job. ;)

Thanks for all the info guys. graemlins/thumbsup.gif

Originally posted by JOHN WILSON:
Casidium coatings ehh? You guys are getting serious with this stuff. :eek: Are ya'll using the coatings on the new motor? Pins & valves etc...?

Yanni- do you think the HP gains would be less evident on a fresh motor? A buddy that posts here (sheetmetal) runs a GZ pump on a fresh 383 with low tension rings and saw very little gains at 12". ...On a fresh motor, the gains are going to come from reduced friction via low tension oil rings and using the pump to provide the necessary ring seal. We found that some of the "low tension" oil rings actually had as much as 22# tension (hardly "low tension"). I believe the standard is about 15#. But, with those, you really don't need a vacuum pump. Real performance gains come from using tensions in the 6# range. We eventually settled on 8# - 10# tension and 10" - 12" vacuum on our backup motor.

The new motor is 6# tension and will run 18" vacuum but has forced pin oiling thru the rod, casidiam coated pins and increased pin clearance. And yes, this motor has lots of coatings and we hope to get 840 hp out of a 381" sbc. That's about 160 more than the backup motor.

John, the engine had 5 runs last year and it was completely freshened up over the winter just before it went on the dyno...

Not sure about the GZ pumps....I like to use proven product and Moroso has been doing vacuum pumps for many years now...

Good luck.

I'll attest to the durability of the GZ pumps. We have about 5000 hard race miles on ours and it works like it did when it was new.

Got at GZ on mine too, sportsmen pro model on it's 2nd year, been holding up great and still pulling vacuum like it should when we tore the car down last fall.

Sorry guys, I wasn't questioning the ability/durability of the GZ pumps. Rather, just thinking the gains seen with a fresh motor would be less than those of a motor with some wear and diminished ring seal.