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Technical What is the smallest mechanical fuel pump for a SBC?

Discussion in 'The Hokey Ass Message Board' started by 56don, Jul 15, 2019.

  1. Is there a mechanical fuel pump that is physically smaller than most of the others that are for a small block Chevy engine?
    I have a 1972 engine that is currently using an electric fuel pump but I want to add a mechanical pump to the engine as a back up. But I do not have enough room to put the Holly fuel pump I bought in because its too close to the frame. Maybe Holly fuel pumps are bigger than a stock pump?
    I was wondering if there is maybe a stock pump that is smaller than a Holly.
    No pics, don't ask....just imagine...:rolleyes:
     
  2. If there is one I'd like to know as well.
     
  3. squirrel
    Joined: Sep 23, 2004
    Posts: 42,668

    squirrel
    Member

    maybe look at pictures of pumps online?

    Beware that there are lots of different orientations of fuel lines on SBC pumps. One that has the lines pointed more towards the engine, than towards the frame, is something like a 72 Impala 350 pump. But I'm assuming the pump fits inside the frame, not over it. No pictures to look at of your car, of course.

    pump.jpg
     
  4. Fordors
    Joined: Sep 22, 2016
    Posts: 1,911

    Fordors
    Member

    C75D2EE7-F049-488C-8A6A-B3A2F3282780.jpeg Jim has the same idea as I, here are comparisons between your Holley pump at top and a Speedway
    Motors pump at bottom. Also look at the distance between the mounting flange and the pump body, some will be shorter. I’m not endorsing any particular pump, but surely there is something that will work for you.
    Keep in mind that even if the pump has adequate clearance as installed you might have to raise the engine to be able to install it. 8572E014-7E05-40C1-9F19-17F4F67C5654.jpeg
     
    Last edited: Jul 15, 2019
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  5. Mike VV
    Joined: Sep 28, 2010
    Posts: 1,470

    Mike VV
    Member
    from SoCal

    Don -

    DO NOT, install a mechanical pump where there is an electric pump in the system.
    You are building a bomb..!
    When the mechanical pumps diaphragm or one way valves leak, the fuel is forced past the leak and into...the oil pan.
    In case you are wondering...fuel in the oil is bad for...many reasons..!
    Had a friend that did this MANY years ago. Beside having to change his shorts, he had to buy a new oil pan, and a LOT of cleaning.

    Mike
     
    rockable likes this.
  6. RAT "T"
    Joined: Mar 27, 2010
    Posts: 298

    RAT "T"
    Member

  7. Rickybop
    Joined: May 23, 2008
    Posts: 5,558

    Rickybop
    Member
    from Michigan

    On the pumps that can be disassembled, you can clock the bottom portion to change the position of the in and out ports.

    Sent from my VS835 using The H.A.M.B. mobile app
     
  8. Rickybop
    Joined: May 23, 2008
    Posts: 5,558

    Rickybop
    Member
    from Michigan

  9. squirrel
    Joined: Sep 23, 2004
    Posts: 42,668

    squirrel
    Member

    AHotRod likes this.
  10. 51box
    Joined: Aug 31, 2005
    Posts: 740

    51box
    Member
    from MA

    Look up Power Products piston pump. I used one in my dragster it was the smallest I could find
     
  11. Rickybop
    Joined: May 23, 2008
    Posts: 5,558

    Rickybop
    Member
    from Michigan

    Website for sale.
    Maybe he'll sell the patent too and somebody else will produce the pump. Sounded like a good product.

    Sent from my VS835 using The H.A.M.B. mobile app
     
  12. squirrel
    Joined: Sep 23, 2004
    Posts: 42,668

    squirrel
    Member

    is that a shaft driven pump?
     
  13. 51box
    Joined: Aug 31, 2005
    Posts: 740

    51box
    Member
    from MA

    It is driven just like a stock pump but I used a aftermarket rod . I had the name wrong it’s Professional Products. This is the one I used 815A3D1E-DB22-4471-8AB8-0A8E8EB21257.jpeg
     
    kidcampbell71 and squirrel like this.
  14. I am not going to use them together at the same time. I had an electric pump go out and I replaced it. I want to have a mechanical pump installed on the engine but not hooked up just in case I lose another electric pump. I don't trust electric pumps.
    Thanks for the replies. I thought maybe someone had used a small mechanical pump and knew off hand what it was for. I am too lazy to research on my own.:oops:
     
  15. Doublepumper
    Joined: Jun 26, 2016
    Posts: 353

    Doublepumper
    Member

    That's an interesting pump. I tried to find some info, but it doesn't show up on their web site. Wonder why?
     
  16. squirrel
    Joined: Sep 23, 2004
    Posts: 42,668

    squirrel
    Member

  17. MAD MIKE
    Joined: Aug 1, 2009
    Posts: 325

    MAD MIKE
    Member
    from 94577

    FYI, profesional products is the Chinese knockoff place that copies parts, badly.
    MSD 6AL like boxes with generic GM HEI modules epoxied to the cases. They would advertise the 'output voltage over 400 Volts' or something goofy for coils.
    They have 'performer' intakes that require more machining than the cheap price saves you. IIRC ole Vics legal team went after them. IIRC they now have a permanent 'out of stock' label on their website for all there Edelbrock copied bits.
    They also used to sell Honda(I know OT) harmonic dampers that were really shitty ripoffs of ATI dampers. How shitty? They would explode above 5Krpm.
     
    AHotRod and dirty old man like this.
  18. Mr48chev
    Joined: Dec 28, 2007
    Posts: 24,984

    Mr48chev
    ALLIANCE MEMBER

    I know a lot of guys including myself who have a basic flow though electric pump as a backup to a mechanical pump or in my case as a primer pump on a rig that only gets driven a couple of times a month when it actually has a job to do.
    I have never known anyone who has a mechanical pump as a backup to an electrical pump and seriously question the wisdom of doing things that way. The pump is going to be operating dry even if it doesn't have lines hooked to it. By the time you need it it will probably be damaged from operating dry.
     
  19. pprather
    Joined: Jan 10, 2007
    Posts: 1,197

    pprather
    Member

    I run on the mechanical pump. My electric pump is the backup. Occasionally I switch the electric pump on when engine seems to vapor lock, like after a quick gas stop on a warm day.
    My Deuce frame is pinched in the front, but I was able to get the GM Performance pump in there. Just need to get the engine rotated so the drive rod is short. Use a hack saw blade between the pump arm and rod to get the bolts started, then pull out the blade and tighten it up. I used several layers of blue painters tape to protect the chassis rail during installation.

    Phil
     
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  20. krylon32
    Joined: Jan 29, 2006
    Posts: 5,775

    krylon32
    Alliance Vendor
    from Nebraska

    I use the pump squirrel pictured on every SBC build I've done. Easy to plumb and easy to find at the local auto parts store.
     
    lothiandon1940 and Hamtown Al like this.
  21. 56sedandelivery
    Joined: Nov 21, 2006
    Posts: 5,595

    56sedandelivery
    ALLIANCE MEMBER

    ^^^^Yes, Professional Products", that does't make any product they have't stolen/copied/don't do any R and D themselves on.^^^^ Unfortunately, when anyone buys their "products", you're supporting their "business model". There are way too many Chinese, and to a lesser degree, Japanese, Taiwan, and almost any Asian country based companies, that do the same thing. It really makes it hard, especially with our somewhat expensive hobby, to decide where to spend our money. Maybe the tariffs will help with that? I am Butch/56sedandelivery.
     
  22. 51box
    Joined: Aug 31, 2005
    Posts: 740

    51box
    Member
    from MA

    I didn’t know that about them. Just looked at summits website for something different that might fit between the tubes and that one worked.
     
  23. 34Phil
    Joined: Sep 12, 2016
    Posts: 183

    34Phil

    One of you guys in a parts store, I wonder if Oldsmobile and SBC fuel pumps share same mount pattern and if not same arm, can you modify it or change pump arm to Chevy. Olds is upside down from Chevy which might put housing high enough to clear frame.
     
  24. squirrel
    Joined: Sep 23, 2004
    Posts: 42,668

    squirrel
    Member

    The direction "up" or "down" on a fuel pump is based on which way the arm can be actuated by the cam, and you can't just change that by installing a different pump. The pump pushrod in a Chevy points downward, so the pump has to be below the mounting surface.
     
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  25. 51box
    Joined: Aug 31, 2005
    Posts: 740

    51box
    Member
    from MA

    @56sedandelivery what company did they rip off with that chevy pump design?
     
    squirrel likes this.
  26. 57tailgater
    Joined: Nov 22, 2008
    Posts: 633

    57tailgater
    Member
    from Georgia

    I remember when those pumps came out by Race Pumps. Seemed like a fairly simple piston type pump but I thought they were more for race applications. Neat idea but apparently not too well accepted.
     
  27. Fordors
    Joined: Sep 22, 2016
    Posts: 1,911

    Fordors
    Member

    Howard Stewart started out making water pumps for NASCAR racers and apparently made Chevy fuel pumps for a while, at least according to the linked Hemmings article. Professional Products was selling that pump, but it's not listed now. Whether or not they were ripping anyone off is anybody's guess, if Stewart gave up on it it's possible that Pro. Prod. bought the rights to it. It's a moot point now, it's gone from their product line up.
     
  28. Mimilan
    Joined: Jun 13, 2019
    Posts: 108

    Mimilan
    Member

    Just have 2 pumps plumbed parallel to a "Y" in the fuel line. And have it so you can switch them over if one fails.
     
    56don likes this.
  29. F-ONE
    Joined: Mar 27, 2008
    Posts: 1,768

    F-ONE
    Member
    from Alabama

    Don,
    The '68 302 in the F1 is running a teeny tiny factory fuel pump. I have no idea what it is or what it's from. It's about a 3rd smaller than the more common pumps.
    What I'm getting at is there may be a factory GM equivalent. With that said, you know how Ford is.....
    92 solutions for the same problem.:rolleyes:
     
  30. Terrible80
    Joined: Oct 1, 2010
    Posts: 691

    Terrible80
    ALLIANCE MEMBER

    Why not just buy a spare electric pump and throw it in the trunk? Or plumb them in line?

    Sent from my LG-TP450 using The H.A.M.B. mobile app
     

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