Technical Vapor Lock

I'm running the cowel tank on my Model A with a nailhead. I'm running an electric fuel pump on the firewall right beneath the tank. Then I have rubber fuel line running to the carb a few inches above the intake manifold. I can't run with the hood on because I get vapor lock. I thought of mounting the pump down on the frame but that still leaves a couple feet of fuel line running down the firewall. I might have the same problem. Anybody have any ideas?

 

have a picture of the set up, any way to put something between the manifold and fuel line to block heat. I have seen people wrap the fuel lines with tin foil or you coul try using a stainless steel fuel line, anything to help heat reduction. can you route the fuel line without being over the manifold but still to the carb.

 

Is their some sort of return on the fuel line, I wonder if the fuel pump pushing against the regulator (which I presume that you have) is causing the fuel to heat up.

I wouldn't be a fan of a couple feet of rubber fuel line, NHRA specs (which are probably overkill) are 12 inches total in the system. Now running a hard line where its in the path of the fan, that might be a good idea.

 

I thought about stainless line. I really don't want to wrap it in foil. I think it would look like crap.
There is no return line. I'm not running a rgulator. If I reroute it I would use metal line from the pump, down to the frame, up to the front of the motor. The Rubber the last ffoot or so.

 

Clothes pins on the fuel line, it's traditional.

 

i have seen the clothes pin option used many of times ..

also have a few articles at home regarding this topic ...

 

Pump on cowl below tank ?
Is your pump inside? If so this is bad bad bad
Or
Is your electric pump outside on the fire wall too close to the engine? If so this is "just bad", they don't like heat.

Your fuel line should be in the breeze of the fan up the front of the engine and the electric pump out of direct heat path. A return line will help a lot.

I'd like to see some pics too.

 

The pump is on the outside but it is pretty close to the engine.

I don't get the clothes pins!

 

Clothes pins pickup the heat from the line which lowers the temp of the fuel. Wood clotes pins got me to high school 45 years ago.

 

Tin foil aside, there are line insulation like you would use for ignition wires that jegs sells, really good stuff. I work in aviation and our lines are all stainless or have a high temp heat wrap insulation similar to what jegs has to offer for fuel lines, they also offer heat wrap blankets for starters and what not and can be used for a fuel pump as what I did, and I wrapped my hard lines from where the hard lines begin to enter the engine bay to the pump and after the pump with the insulation sleeves jegs offers as well replaced rubber fuel lines with stainless in conjunction with a heat blanket for the fuel pump, then used header wrap for the exhaust headers back to about two feet past the firewall, then again with header wrap where the exhaust gets close to the fuel tank. Huge improvements. It helps that you have a clean fuel cell, good non corroded fuel lines, working order fuel pump, clean fuel filter. And the old flathead purrs with out using clothes pins, didn't come from the factory and shouldn't need it, again it didn't come with insulated fuel lines but with advances today we take what was and improve it in ways to improve effectiveness without sacrifice of sleek style.