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Flathead vapor lock

Discussion in 'The Hokey Ass Message Board' started by JerryP., Mar 26, 2010.

  1. JerryP.
    Joined: Mar 26, 2010
    Posts: 1

    from Tucson,AZ.

    Can someone help with vapor lock on my flattie? I added a inline fuel pump, which stops it when starts to lock but I would like to eliminate the problem. By the way it's a stock 8ba in my 50. Thanks
  2. 53ash
    Joined: Sep 9, 2005
    Posts: 176

    from Plano, TX

    Easy trick on the road. Clip some wood clothes pins on the fuel line. They work to get rid of heat. Long term. You can move the fuel line to a cooler location, or insulate the fuel line.
  3. Back in the day when we had flatheads had to carry water to pour over fuel pump to cool it down, later tried the clothes pin trick that worked.
  4. uncle max
    Joined: Jan 19, 2006
    Posts: 890

    uncle max

    A lot of flathead "vapor lock" problems can be cured with a new NAPA Echlin IH-200 condensor.
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  5. 4dFord/SC
    Joined: Sep 12, 2004
    Posts: 782


    How many clothes pins will it hold? ;)
  6. I am having the same "vapor lock" issue with the flat head V8 in my 49 ford. It was above 90 degrees yesterday and it locked up a few times after I started it and then took off.

    Is the NAPA condensor a direct replacement for my flattie?? thanks!!

  7. xlr8
    Joined: Jun 26, 2006
    Posts: 629

    from Idaho

    Try gas from different sources. If you have winter blended gasoline that you bought last fall, get rid of it or put in just a little diesel fuel until you can get it burnt off. Try to buy gas with no ethanol. Some gas is way worse for this. Premium sometimes helps, too.
  8. flatjack
    Joined: Feb 13, 2007
    Posts: 732


    Ther is no way a clothes pin can dissipate heat. Wood is an insulator. The wood shields the gas line from the heat at best.
  9. I'm having a vapor lock problem with my '56 I've been chasing for 2 years. Only does it if just barely moving or idling for a long time. If I got in one of those 15 mile interstate traffic jams I'd just have to pull over until they got it cleared up. I put an electric fuel pump on it and it did delay it some but still does it. I put a water hose right on top of the fuel pump the other day and it never did it and the gas never boiled. (I have a clear plastic fuel filter). The carburetor never gets so hot you can't touch the bowls (have a 1" plastic spacer under it). Have rubber fuel lines from pump to carb. The line from the fuel tank runs outside the frame all the way up so is never close to a heat source. Next move is high test, no ethanol fuel, (if I can find any).
  10. 4dFord/SC
    Joined: Sep 12, 2004
    Posts: 782


    It's actually for International Harvester tractors, but it works well on flatheads, too.
  11. hotrod40coupe
    Joined: Apr 8, 2007
    Posts: 2,559


    Install an electric fuel pump back by the tank, remove the stock fuel pump and shield ALL the fuel lines from ANY heat source. That should cure your problem. Electric pumps push better than pull.
  12. dudley32
    Joined: Jan 2, 2008
    Posts: 1,837


    the clothes pin stops the heat(insulates)from climbing up the metal gas line..d32
  13. xhotrodder
    Joined: Jul 2, 2009
    Posts: 1,390


    I have a friend with a stock 41 Ford flathead. He has been plagued with the vapor lock problem for several years. He has tried the clothes pin route, and insulating the fuel line also. Neither seems to help him, when it is really hot.
  14. Gotgas
    Joined: Jul 22, 2004
    Posts: 6,258

    from DFW USA

    Vapor lock occurs when fuel is allowed to boil. Only two things you can do to affect that; one is to insulate the fuel from excess heat, the other is to increase fuel pressure. Higher fuel pressure makes the vapor lock situation happen at a higher temperature; hopefully higher than your fuel is ever allowed to reach.

    Most vapor lock issues I've dealt with have been due to a weak fuel pump (pressure too low). Usually one of those phenolic or fiber 1/2" carb spaces will keep the carb cool enough to keep vapor lock at bay even with a slightly weak pump.

    In short, check your fuel pressure and make sure it's in spec.
  15. in my situation, I think the CARB is the issue, not the fuel line running to it. It may also be a weak fuel pump. (have to check it) I think the fuel is getting through the line and boiling when it enters the carb causing the vapor lock. The fuel line (not rubber) is not even hot to the touch and is 3-4" away from the engine.

    After is locks and I pour some gas into the carb I can hear it boiling and sizzling.

    If I put a fiber spacer (as mentioned above) between the carb and engine, I suspect this will help keep the carb cooler.

    and again, it has been in the high 80's here the last few days when this is happening. It is cooler today and I will run it and see what happens.

    I will also be moving to Columbus OH in the next month or two and I doubt the high heat and humidity will help my cause!!!!!!! DAMN.

  16. Ole don
    Joined: Dec 16, 2005
    Posts: 2,914

    Ole don

    When in heavy traffic on a hot day, instead of following the car in front at four feet, follow at twelve feet. Your engine will be ten to twenty degrees cooler. The fuel pump on my Y block was meant for a 292 truck, it is the same one used for a 427 single four barrel engine. My car has never vapor locked.
  17. NOLUCK13
    Joined: Feb 17, 2010
    Posts: 104


    I had the same problem with my flattie. I rerouted the fuel line and put in a electric fuel pump and new fuel filter and that seemed to solve my problem. It gets pretty hot here in Austin, Texas and I haven't had a problem since!
  18. haychrishay
    Joined: Jul 23, 2008
    Posts: 920


    Don't run ethanol mixed gas, run premium.
  19. bobscogin
    Joined: Feb 8, 2007
    Posts: 1,653


    Wouldn't blocking off the exhaust crossover make the carb run cooler?

  20. I am gonna order up the electric fuel pump and see where that gets me. thanks for all the advice fellas!!

  21. lonewolf
    Joined: Sep 2, 2006
    Posts: 382


    I had the same problem with my 51 ford.....check your timing that plays a major role, Is it advancing? also what i did was ran straight vinigar in the radiator for a week and flushed it out had to do it twice youd be surprised the shit that comes out

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