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Technical Pontiac Straight Eight Fuel Pump Question

Discussion in 'Traditional Customs' started by SJ, Mar 27, 2016.

  1. SJ
    Joined: Jun 20, 2012
    Posts: 19

    SJ
    Member
    from Boise

    I am in the process of rounding up the rest of the parts to finish off my straight eight build, this is my first build attempt so this may sound like a dumb question but I will be running two stromburgs and from what I understand I will need to regulate the pressure to around 2.5 to 3 pounds. The question is the original pump is in poor condition, and I'll be replacing it, do I need an oem style pump for the Pontiac or can I run something like the Holley mechanical pump? Is there any added bonus with a higher performing pump with a straight eight/6volt setup? Not exactly sure how to regulate the pump either so if anyone has some good advice I'm all ears I am sure Ive made this a lot harder than it needs to be. This entire thing is a learning experience for me any wisdom is appreciated.

    Thanks for the help

    SJ
     
  2. bobbytnm
    Joined: Dec 16, 2008
    Posts: 1,375

    bobbytnm
    Member

    I can't help you on what pressure you need for 2 Strombergs. I'd be interested in the answer because someday I want to run several carbs on my straight t8 Packard. Years ago I had a 49 Pontiac with a straight 8. When I got the car the fuel pump was missing. A new fuel pump + core charge was going to cost me more than I had paid for the car.
    I ended up scrounging though the parts books and ended up using one from a 6cyl Ford. I also found one for a John Deere tractor that would fit. I think I did have to drill the bolts holes on the pump out a little larger but it worked great. It didn't have the vacuum pump part of it, it was fuel pump only.

    Good luck with your quest. Do you have any pics of your multi carb set-up? I love a straight 8

    Bobby
     
  3. 302GMC
    Joined: Dec 15, 2005
    Posts: 6,251

    302GMC
    Member
    from Idaho

    Pump OH kits are available with new & improved parts to withstand our now crappy gas. It's fun to rebuild a dual action pump, if that's what you have. If pressure with mechanical pump exceeds your need, shim pump out with several gaskets.
     
    Last edited: Mar 28, 2016
  4. SJ
    Joined: Jun 20, 2012
    Posts: 19

    SJ
    Member
    from Boise

    Thanks guys for the info, my engine is currently at the machine shop but as soon as its out I'll post pics, I am in the process of moving to Idaho so things are a little crazy right now...302 GMC that is interesting about the "crappy gas" that is something I had not thought about, so I just want to be sure but you are saying that if I purchase a mechanical pump and the pressure is excessive ie more than 3lb psi then shim it up with gaskets? Whats your thoughts on going with an electrical that has a regulator? or would I need a 12 volt setup to do that?

    Again I appreciate the help I am new at this but I just have a few more parts to go and I can start reassembling.

    SJ
     

  5. Champscotty58
    Joined: Jul 1, 2010
    Posts: 119

    Champscotty58
    Member

    My brother has a '54 Pontiac, all stock. He was having problems with his mechanical pump. I installed a 6 volt (4-6 psi I think) electric pump on the frame rail near the rear of the car, in line with the original fuel line. Then installed a Mr. Gasket style select-able regulator on the inner fender in the engine compartment. I think we set it at 2.5 psi and it works out great. Had to re-route the vacuum lines that were attached to the original pump, but it was all pretty straightforward. Might be something to think about
     
  6. 302GMC
    Joined: Dec 15, 2005
    Posts: 6,251

    302GMC
    Member
    from Idaho

    Assuming the carbs are 97s. However, if they're 4 bolt for a non - Ford engine they'll withstand 5 lbs if fresh. Same info on pump parts applies here - use new style Deathanol proof parts. An electric pump and filter mounted by the tank is always a good idea. When the car is idle for weeks, an electric pump cuts the long cranking time to fireup down to seconds. Most of us use the electric pump as standby, pumping into the factory pump and shutting power off when not in use.
     
  7. Fadi
    Joined: May 1, 2014
    Posts: 19

    Fadi
    Member

    Agree on the electric fuel pump; which can be 6 or 12v. Also, you could run a pressure regulator in line with any pump to dial in the feed to the carbs if you wanted. The holly reg I have on my 303 Rocket to control flow from a 6v electric pump was maybe $15.
     
  8. 40 Olds
    Joined: Jul 2, 2008
    Posts: 55

    40 Olds

    I ran my 97's on the mechanical pump with reg set @ 2 lbs for 4 years until the mechanical pump failed. Now using a small electric pump with same reg setting. Just got a rebuild kit for the mechanical and will leave the electric in place (at the tank) like 302Gmc said, to help after sitting for a while
     

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  9. stimpy
    Joined: Apr 16, 2006
    Posts: 3,547

    stimpy

    the little facet square electric pumps work perfect as they are set for 2-4 pounds from the factory , only thing is you loose the vacuum pump for the wipers , I use a company called "then and now out" of mass , there guy Mike , knows fuel pumps and has been working on alcohol resistant parts for them .
     
  10. scrmkr
    Joined: Nov 19, 2011
    Posts: 16

    scrmkr
    Member
    from memphis tn

    I'm just getting started getting my '53 Chieftain I picked up last fall road ready. Planning on keeping it original so I want to get rid of the noisy electric fuel pump the previous owner installed. The old mechanical pump is still in place so I'm considering rebuilding it. I'm looking for advice as to whether I should rebuild it (and what kit to use) or should I stick with an electric pump and try to lessen the noise.
     
  11. Rusty O'Toole
    Joined: Sep 17, 2006
    Posts: 9,291

    Rusty O'Toole
    Member

    Just buy a stock rebuilt fuel pump from your local auto parts store. If you want a pressure regulator install it just before the carburetors, before you split the fuel line.

    Even with twin carbs you will not exceed the capacity of the stock pump.
     

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