Vacuum pumps???

Discussion in 'Race 400/430/455' started by SS/GN, Aug 31, 2019.

  1. SS/GN

    SS/GN Well-Known Member

    I have used header collector evac and pcv systems and a combination of both. Typical HP gains over just valve covers vented to atmosphere were in the 3-7 HP range. Curious to see if anyone would share there experience and HP increase number's using a vac pump set up.

    Thanks in advance
  2. nickbuickgs

    nickbuickgs nickbuickgs

    Just dynoed with wet /vac external pump . Depending on ring package , A well sealed block ie no leaks , & Cylinder hone . I just had a almost a 40 hp vs disconnected vac pump
    Last edited: Aug 31, 2019
    dan zepnick and alaskagn like this.
  3. slimfromnz

    slimfromnz Kiwi Abroad

    We had a 37hp gain if memory serves me right
  4. Steve Reynolds

    Steve Reynolds SRE Inc

    I think my GSX 523 was at 35hp difference with the line cracked open vs. sealed up.
    Last edited: Oct 2, 2019
  5. HotRodRivi

    HotRodRivi Tomahawks sighted overseas

    Thats quite a big gain in HP. Does the vac pump do anything to the oil? Are you just removing the positive pressure so the pressure is not working against the pistons? Or are you actually sucking the pistons down. But then that would not be good for the upward travel.
  6. Steve Reynolds

    Steve Reynolds SRE Inc

    I really doubt that 8-15 inches of vacuum have much of an effect on the travel of the pistons. If you think about it, the crank case is a vacuum chamber at this point, and if one piston is coming down, another is coming up (and so on) so the volume of space (cubic inches) in this chamber stays relatively the same throughout the revolutions.
    Oil pressure is a concern though, as the vacuum pump and the oil pump both fight each other in terms of pulling volume from the crankcase. As vacuum is increased the oil pump must work that much harder to supply the same oil pressure. If no changes are made to the oil pump with the addition of a vacuum pump, you'll definitely see a decrease in oil pressure.
    SS/GN likes this.
  7. Bens99gtp

    Bens99gtp Well-Known Member

    I dont have one, but have known more than one guy to up the vac level and suck so much of the fine oil mist out of the motor to burn up pins and other parts needing that oil. I think the main goal with the pump is to just keep the rings sealed???? Correct
    SS/GN likes this.
  8. Steve Reynolds

    Steve Reynolds SRE Inc

    Pretty much ...... yes. From my experience there's not much gain beyond 8-10 inches.
  9. GS Kubisch

    GS Kubisch THE "CUT-UP" BUICK

    BuickGSrules likes this.
  10. GS Kubisch

    GS Kubisch THE "CUT-UP" BUICK

    Vacuum on a data logger is also a great way to monitor the "health" of your race engine.
  11. BuickGSrules

    BuickGSrules Gold Level Contributor

    Anyone know were to search for an Electric pump? Will run a belt driven on the race motor, but would be great to have an electric for the stocker when at the track.
  12. Houmark

    Houmark Well-Known Member

    I can check with our vendors of pumps.. You would like it to be 12v right?
  13. Daves 71 GS

    Daves 71 GS Well-Known Member

    Star makes an Electric vac pump.We used one on the promod for a little while.They are pretty pricey.
    Last edited: Sep 30, 2019
    BuickGSrules likes this.
  14. BuickGSrules

    BuickGSrules Gold Level Contributor

    Could be great, thanks. Yep, 12v.
  15. hugger

    hugger Well-Known Member

    The 4th Gen electric Fbody pumps pull a few in
  16. alvareracing

    alvareracing Well-Known Member

    we were able to achieve 4 inches with those electric ones from the GM f body ones Hugger is talking about. But the motor they went on, had perfect ring seal and all crevices sealed tight. The biggest problem with them is that, they cannot take in any oil or they will burn up. So be careful how you plumb those in to keep them away from oil. Ford also made an electric one that we tested and it worked, but the same issues with burning up the little motors. We used two of them on a SBC one for each side of the motor and we got about 7 + inches which seem to worked pretty good. It took some ingenuity plumbing and wiring to get them to come on automatically when the throttle was 50% or more. So far they are still working on that same motor.
  17. Houmark

    Houmark Well-Known Member

    40190454 his name is Søren, and is apperently owner of a company that suplies spareparts for lifts, glass-lifts etc, and when I spoke to him ealier today he had 12v vacum pumps..
    BuickGSrules likes this.
  18. Buizila

    Buizila GO BROWNS !!!!!!

    I was looking to do a setup with a smog pump from the ones GM uses on the Chevy Trailblazer

    BuickGSrules likes this.
  19. 300sbb_overkill

    300sbb_overkill WWG1WGA. MAGA

    For your stocker, just hook the breather to manifold vacuum so you have your PCV and no breather and you'll have 18 + inches in your crankcase.

    Of coarse that 18 in. will go down at WOT but you didn't need that much anyway.
    BuickGSrules likes this.
  20. SS/GN

    SS/GN Well-Known Member

    We could not run a vac pump on our super stocker but ran a pcv and header evac combination and it showed a few HP on the dyno. It is my understanding that with a low drag piston/ring set up the vac pump would help control ring flutter and seal , therefore make more HP. Never dynode this so I was reaching out to the board for some input. All the opinions on this is exactly what I was thinking. Good info

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