Header - Fuel and Brake line clearance

[jayd]

I've built a 1937 Dodge pickup on an '89 S10 frame and there are a couple of possible header heat issues with the fuel line and a brake line. It has a SBC with block hugger headers, the headers have been wrapped.

A section of the fuel and right front brake lines come within 2" of the headers. I can make some heat shields and wrap the lines with some header wrap. Would this be adequate to avoid heat issues?

The fuel line will be difficult to relocate, not much room up front and it feeds a stock pump. The brake line can be moved but will require replacing the tubing.

[blwn31]

I would try to relocate them if possible. If not, fabricate a small baffle to shield the lines from the heat.

Keith

[IC2]

I'm within a couple of inches of those lines as well, with as yet no problems - though am not running hood sides and may be keeping them cool enough. Probably a heat shield open at both ends from a piece of 16ga aluminum will be enough.



The brake line is ~2" just below that fuel line clamped to the boxed frame rail

[Mike P]

Jayd personally I wouldn’t worry too much about the brake line as long as you have a minimum of 2” clearance.

The fuel line may or may not be a problem, safety wise you’re probably OK but there is a real potential for vapor lock problems, and a lot of factors that can come into play:

Amount of heat that is coming off the headers.

Quality of fuel, the oxygenated (ethanol) fuel seem to vapor lock more readily that non-oxygenated gasoline.

Fuel line size and your rate of fuel consumption. The longer the fuel stays in the line the more heat it tends to pick up.

Altitude, the higher up you are the more susceptible you are to having vapor lock problems.

Outside temperature.

A few tricks that can help. One is shielding. Some people also have good luck running a supply pump at the tank (3-4PSI) which will pressurize the fuel in the line and reduce the tendency for vapor lock. On vehicles that have major vapor lock problems the only cure is usually a return line as close to the carburator as possible. This keeps the fuel in constant circulation and prevents it from staying on one place long enough to pick up heat and vapor lock.

[rspears]

Jayd,
I agree 100% with Mike and Dave. My initial thought was that a localized hot spot is not going to affect your brakes - captive system, non-compressible fluid, etc. Like Mike says your fuel line may or may not cause you problems. The most potential problem is going to be those dog days of summer, sitting at a stoplight waiting for traffic, or even shutting down hot and restarting a few minutes later. If you're running EFI you likely have a return line, which is going to minimize the problems of a localized hot spot. If not you might look at shielding that area. If it were mine I would run it and see how it does before I start fixing something that may not be a problem. For me, going to the hassles of relocating lines would be several notches down the list. You may not need to do anything.

[jerry clayton]

An ounce of prevention is worth a pound of cure

A shot of prevention is worth a fifth of repair

I will not build or work on anything with less than 6 inches of distance from exhaust system to brake or fuel components

[jayd]

Thanks for the excellent responses, I moved the fuel line and will be moving the brake line too, just to be sure.

I have a '30 Model A with the same issues, but no hood, this pickup has a hood and fenders. The Model A has not given me any problems, been driving it for 5 years. I've heard these style cars and trucks are hard to keep cool, just don't want to have any vapor locks or boiling brake fluid.

[Mike P]

:...A shot of prevention is worth a fifth of repair ...." Ain't that the truth

jayd if you could let us know how the truck does thru the summer. I'd especially be interested in knowing any heating issues you may have as I am building a 37. What are you running for a radiator and fan setup?

I'll be plumbing in a return line when I get to that point on mine (and probably running with the hood top but no sides).