Re: vacuum pump - when is it needed?
[Re: OUTLAWSSAA]
#1700950
11/20/14 01:40 AM
11/20/14 01:40 AM
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Joined: Mar 2006
Posts: 9,863 MI, usa
dvw
master
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master
Joined: Mar 2006
Posts: 9,863
MI, usa
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My bet at your level it doesn't need it. Stop any oil leaks,helps power when ring tension is light. I like the GZ kit. Reasonably priced,holds good vacuum. www.gzmotorsports.com/Doug
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Re: vacuum pump - when is it needed?
[Re: dvw]
#1700951
11/20/14 01:41 AM
11/20/14 01:41 AM
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Joined: Mar 2006
Posts: 9,863 MI, usa
dvw
master
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master
Joined: Mar 2006
Posts: 9,863
MI, usa
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Re: vacuum pump - when is it needed?
[Re: 69dart]
#1700953
11/20/14 11:43 AM
11/20/14 11:43 AM
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Joined: Jan 2003
Posts: 13,377 Marion, South Carolina [><]
an8sec70cuda
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 13,377
Marion, South Carolina [><]
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69dart...On your combo, it's wasted money. A race only long stroke and/or high rpm engine w/ low tension rings can benfit from one. I say race only b/c they are a PITA on a street driven car. If you do decide to get one for some reason, stay away from the Aerospace Components pumps and mandrels.
CHIP '70 hemicuda, 575" Hemi, 727, Dana 60 '69 road runner, 440-6, 18 spline 4 speed, Dana 60 '71 Demon, 340, low gear 904, 8.75 '73 Chrysler New Yorker, 440, 727, 8.75 '90 Chevy 454SS Silverado, 476" BBC, TH400, 14 bolt '06 GMC 2500HD LBZ Duramax
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Re: vacuum pump - when is it needed?
[Re: JACK1440]
#1700957
11/20/14 11:52 PM
11/20/14 11:52 PM
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Joined: Nov 2003
Posts: 10,384 Upstate NY
Bigcube
I Live Here
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I Live Here
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Posts: 10,384
Upstate NY
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Header evac systems will smoke bad if you run mufflers. They do not work if there is back pressure in the exhaust. Had the same issue with mine.
I run a Moroso 4 vane pump. It was proven to be worth 25-30 HP with my combo. It would pull about 2 oz of oil on every run. Not something you would want to use on the street.
Jim
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Re: vacuum pump - when is it needed?
[Re: 69pwgt]
#1700960
11/21/14 11:31 AM
11/21/14 11:31 AM
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Joined: Jan 2003
Posts: 13,377 Marion, South Carolina [><]
an8sec70cuda
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 13,377
Marion, South Carolina [><]
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Quote:
i'm looking to put one on my mostly street car (leaks from rear main). Why are you saying they are no good on the street?
My suggestion is replace your rear main seal or find out why it's leaking. I'd never install an $800+ kit to stop an oil leak. You need the motor sealed up good anyway so the pump can draw vacuum. Unless your engine is a pretty nasty piece and really needs to vent better.
Vacuum pumps aren't designed for continuous duty (like street driving)....they don't pull enough oil through them at low RPM to lube the pump good and wear out fast. You can add a little oil to the pump before you go for a drive, but that doesn't last long.
GZ makes a pump that recirculates the oil from the catch can through the pump to help w/ street driving...they are the only ones that do this that I know of.
FWIW...I'll never run a vacuum pump again on anything that sees the street. A pair of big lines from each valve cover to a breather tank works just fine. Pulling 8-10" of vacuum (all my Aerospace pumps ever get) made zero difference in how my car ran...w/ a 572" hemi that has low tension rings. Maybe it isn't enough vacuum, probably should have bought a different pump, etc. My best ET was w/ just a pair of breathers on the valve covers. Maybe it would make more of a difference w/ a better pump pulling more vacuum, but I have my doubts. My motor is far from a radical race engine though. It makes a little over 800 hp N/A on pump gas.
CHIP '70 hemicuda, 575" Hemi, 727, Dana 60 '69 road runner, 440-6, 18 spline 4 speed, Dana 60 '71 Demon, 340, low gear 904, 8.75 '73 Chrysler New Yorker, 440, 727, 8.75 '90 Chevy 454SS Silverado, 476" BBC, TH400, 14 bolt '06 GMC 2500HD LBZ Duramax
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Re: vacuum pump - when is it needed?
[Re: AndyF]
#1700962
11/21/14 06:06 PM
11/21/14 06:06 PM
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Joined: Aug 2003
Posts: 43,251 Bend,OR USA
Cab_Burge
I Win
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I Win
Joined: Aug 2003
Posts: 43,251
Bend,OR USA
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Back when the vacume pump systems where being introduced into drag racing most of the dyno tests done on a A,B,A test basis found that most vacume pump system didn't gain any measureable HP below 6000 RPM, this was on both BB and SB Chevy motors of course. The higher the RPM tested the more HP gained I have a 3 vane Moroso vacume pump that I am planning on using on my next BB Mopar all out stroker, 555 C.I. , bracket race motor build I'm shooting for 15 to 17 inches vacume at the upper RPM, above 6000 RPM probally, shifting at or above 7400 RPM
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
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