electric fuel pumps

RonS
RonS Senior Contributor
edited November -1 in HUDSON
Does any one use a 6 volt solenoid( inline) electric fuel as the soul source for their hornet? I discovered something today, they can't replenish the twin h fast enough . I used two differant pumps same results. With engine off & pumping ( to simulate priming the carbs)= 4 psi at the carbs. Kinda weak, since they claim 5-8 psi. So I ran 10 feet of hose,in order to see if there is any restriction. Same result. Started the engine; in about one minute the pressure dropped from 4psi to 2 1/2 - 3 PSI with the engine idling. Another slight drop on throttle. With a volumn test, only 10 oz was pumped in 30 seconds. Too little.
Now, who uses a Carter rotary vane as the only fuel pump? At 72 GPH, they would appear better, size aside.

Comments

  • 53jetman
    53jetman Senior Contributor
    I have run my '53 Superjet now for almost five years with the Carter Rotary Vain pump as the sole source of fuel for the Twin-H Power on the 202 CI engine. Works great! No problems starting or running extended trips of as much as 550 miles without turning off the engine. I'd recommend the Carter pump to anyone, I can see no reason that this pump would not give outstanding service on a 308 CI with Twin-H Power.

    Jerry
  • RonS
    RonS Senior Contributor
    Jerry, do you have a pressure regulator in line?
  • Unknown
    Unknown
    edited May 2011
    RonS wrote:
    Jerry, do you have a pressure regulator in line?

    Interesting website pretaining to the use of regulatorswith the Carter Rotary Vane pumps.

    carter1.jpg
  • RonS
    RonS Senior Contributor
    what's the site?
  • TwinH
    TwinH Senior Contributor
    RonS,If you put your cursor over "regulators" in WildWasps post it will hilight in red and left clicking will take you to the link.

    The problem is there isn't enough contrast between the brown text for a link and
    the black text in the post. I wonder how hard it would be to change the color
    for the text links.
  • 53jetman
    53jetman Senior Contributor
    Ron, I don't use a regulator anymore - I did when I used the solenoid type as a booster when needed to eliminate hard starting when hot, or to pump up the fuel on a cold start. Have not had any problems without a regulator.

    Jerry
  • [Deleted User]
    [Deleted User]
    There is absolutely no reason, or need to add an external regulator to the Carter Rotary Vane Pump. The Carter #4259 is a 6 Volt Pump, internally regulated at 6 PSI, and a flow rate of 72 Gallons/Hour. The pump has a wet motor that is cooled by the gas as it pumps which helps add to it's lifespan. In addition it is completely compatible with any modern alcohol blended gas which tends to turn the diaphragms in the soloniod pumps to jelly. Hopes this is a help.
  • RonS
    RonS Senior Contributor
    Great! Thanks. The "jelly" is why I need to replace the solenoid. I noticed a substance resembling a plastic wax on the floor. It was the sealant in the pump oozing out. Also, the pump was too weak on volumn & for any thing more stressful than a steady speed. It was overwelmed by long grades.
  • RonS
    RonS Senior Contributor
    The rotary pump comes with 2 3/8 hose barbs. Do you guys run 3/8 fuel line, or 5/16? The pump is rated @ 5 3/4 psi. Will dropping to 5/16 line raise the pressure enough to require a regulator? Can I even use a regulator? The link that is on a previous reply said no regulator, but over 5psi will probably flood out at idle.
  • [Deleted User]
    [Deleted User]
    Just get yourself a couple 5/16" brass nipple fittings to thread into the pump, and plumb it right into your 5/16" line. It will work fine, and still no need for an additional regulator. Be sure to install an inline fuel filter between the tank, and the new pump. ;)
  • bob ward
    bob ward Senior Contributor
    From RonS
    The rotary pump comes with 2 3/8 hose barbs. Do you guys run 3/8 fuel line, or 5/16? The pump is rated @ 5 3/4 psi. Will dropping to 5/16 line raise the pressure enough to require a regulator? Can I even use a regulator? The link that is on a previous reply said no regulator, but over 5psi will probably flood out at idle.

    I had a discussion a while ago with the guy who does my carby work about electric fuel pumps and Carter stepdown carbs, and his opinion that 5psi was too high for them, 2 or 2 1/2psi is what the needle & seat will handle.

    All you can really do is try the set-up you have, and if fuel is being pumped straight through the carbs fit a pressure regulator.

    I've recently needed a regulator for a project (one of those little square fuel pumps feeding an SU carb) and bought the Sytec brand. The regulator works well and can be set from 5psi down to as low as 1/2psi
  • RonS
    RonS Senior Contributor
    I already have a regulator in line from the last pump. WA1s should receive 3 1/2 to 4 1/2 psi. The last two little solenoid pumps produced only @ 2 3/4 psi at the carbs. The engine starves for fuel under sustained load, like driving up mountains even in 72 degree days. Hornet just sucks up too much fuel for 'em.
    Any suggestions from experience, where to mount a rotary on a hornet frame? These pumps are rather big.
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