Right now, my fuel line is sitting only 2 or 3 inches from my drivers side header. I know that I don't really have to worry about vapor lock because with the higher fuel pressure that our TPI systems run, vapor lock isn't a problem. I've been running with the fuel line like this since last October when I installed the new engine and the headers. However, could the extra heat on the fuel line be causing extra built up pressure in the fuel system which would be causing my vacuum canister to smell strongly of fuel?? Any opinions on this would be greatly appreciated.

 

Wow, I was just going to ask this same question. As far as the pressure is concerned, I'd think it would just be relieved by the fpr. Mine are much closer then yours, more liek 1/4" (but just for a little bit where they go over the corner of the frame rail) and my concern is a vapor bubble developing right after I shut the engine off. I think that this wouldn't be a problem, agian because of the closed loop system and the fact that fuel is moving through it rather quickly.

Someone hopefully can offer a more certian answer.

 

The feed/return lines are a closed system with a check valve in the tank.

If you smell fuel at the vacuum canister, time to R&R it.

Since the front Y-pipe on the Vette is very close to the fuel filter it has a stock heat shield.

 

That wouldn't be happening either because even after you shut off the engine, the fuel line is still pressurized and will only leak down over a period of time. By the time the fuel pressure goes down far enough to cause a problem, the headers will have already cooled enough so that it's not a problem. 40-50psi is going to raise the boiling point of fuel quite a bit. Water normally boils at approx. 210 degrees and by adding a pressurized radiator cap, it increases the boiling point of water. Now keep in mind that we only use about 13psi radiators caps. Our fuel pressure runs 3-4 times that amount of pressure so you can imagine how high the boiling point of the fuel becomes. Carbed engines only run about 3-7 psi so they have more of a worry when it comes to fuel lines and heat.

I just recently found out that the stock thirdgen gas cap isn't vented and it relies only on the vaccuum canister to vent the fuel system .... so I think I'm going to try adding a vented gas cap and seeing if that helps out a little bit. I'm sure it will help out... how much I don't know. I'll find out though

 

So the consensus is that metal fuel lines running in close proximity to headers on a TPI car are nothing to be concerned about?

 

That's what I gathered when I posted a topic asking about vapor lock and TPI at the end of last year when I put the new engine in and originally had the problem. It also makes complete sense and I've not had a problem with it since last October. If you don't feel comfortable with it just cut the line, have the line re-bent so it doesn't come near the headers, then have the lines fitted with fitting and attach the lines back together making sure to use plenty of teflon tape.