Vapor Lock
 

Hi, I'm a new Cobra owner with a vapor lock challenge. Here's what I have:
'69 Ford 302 purchased from Engine Factory in NJ
Edelbrock 7121 Manifold
Edelbrock 1806 Carb

Whenever I would travel for an hour or so and shut the car off, it would not start up unless I let it sit for 20 minutes or so. Edelbrock & Engine Factory told me to buy a spacer plate #8711, which I did and it seemed to solve the problem most of the time. Any other ideas that I might employ to solve the problem ALL of the time? BTW, I do have a steel braided fuel line that is elevated away from the engine block.

Much appreciated,
Blake

Try a turkey pan.

I am running the same engine, no problems with vapor lock, I did change the 750 Edelbrock out for a 670 Holley dual inlet, just thought the 750 was too much, are you sure you don't have an ignition problem, I also switched to a Mallory distributor and Hyfire ignition module and pro coil, I have never had any problems with the engine starting, it does run cold, takes several minutes before it warms up enough to run smooth and idle right

Fuel in carb is evaporating due to heat from manifold.

The suggestion about the turkey pan will definitely solve the problem.

You could always add a second spacer as long as air filter does not hit the hood.

Thanks for the suggestion on the ignition....I never thought of looking there. The motor(crate from engine factory) came with standard coil and Accel distributor. I simply connected it to the ERA electrical system. I'll check with both to see if I did something wrong.....much obliged......

being a novice, where does one get a "turkey pan"......would Summit Racing be a source......looked in their index and no such thing. Is it called by another name......much obliged!

Try..cobra accessorier $245.00
http://www.cobraaccessories.com/cata...products_id=31

ERA sells them (talk to Peter) as well as Tony Branda (Branda Performance Inc.) http://www.cobranda.com/airclre.html

John

BlakeC, the problem you describe is heat soak induced vapor lock. Because this does not happen while driving I am assuming the heat soak, after engine shut off, is evaporating the fuel from your fuel bowls and maybe even the lines a little, along with boiling what gas is left in the carb. This happens because of the low vapor pressures of modern fuel (mixed for higer fuel pressures) There is not much you can do about this other than make certain everything is up to par. Timing is right on, fuel pressure is as high as your carb will take (about 8 psi max, 10 psi in some cases), float levels are correct and seats are tight, insulate and isolate the incoming fuel line as much as possible as well as running as small a line as your motor will take (no fuel return system), or go to a return style system, (a better idea) and try to distance the carb from the heat source...tough to do when the heat source is the motor itself. The under carb spacer works pretty good at heat isolation from the manifold, but does not fix heat soak from hot underhood air simply heating everything under the hood. The 1/4" spacer is just as effective as the 2" spacer at heat isolation with wood being the best isolator, then phenolic, then plastic, then aluminum (I like the phenolic) The "turkey pan" will deflect some radiant heat, as well as allow cooler air from the hood scoop to cool the carb body itself and this will make detrimental heat soak take longer to cause problems, but it will not make heat soak go away. Nothing can make heat soak go away except for removing the heat. One way to tell if this is really the issue is to drive until you have everything really good and warm (go for an hour long cruise on a warm day) Then stop for lunch somewhere and after about 10 minutes have passed, remove the aircleaner and pump the throttle while looking at the accelerator pump nozzle discharge. If there is no gas, or spurty, airy gas, you have found the issue. If you have clear, full spray, then look elsewhere for this hard start problem. Good luck.