fuel return line needed?

[John Coffey]

Electric pumps should NEVER be deadheaded.(No Jerry Garcia jokes,please)

Huh? Do you want a list of modern cars that dead head the fuel system? Mazda RX8, Nissan 350Z, Audi S4,... Lots and lots of carb cars run a dead headed fuel system with an electric fuel pump.

[John Coffey]

My personal opinion is that it's better & beneficial to use one and it's safer too. If for some reason, gas has no place to go back to and must exit somewhere because of a fuel system problem (eg: a hot engine bay), then I'd rather it be allowed an escape route back to the fuel tank.

Really? Adding a second fuel line running the length of the chassis with all its potential leak points and places for to fail in a wreck is safer?

[John Coffey]

There's really a lot of mis-information in this thread. Probably should be deleted.

[Travel'n Man]

Agreed!

[chaztg]

well I guess we all should bow to your knowledge, because you have all the answers. I don't drive an Audi or a Mazda. My 240 has carburetors and we're discussing an original design from Nissan in which they decided to include a "dangerous" fuel return line....I just looked at the one in my car and after almost 40 years all it's "potential leak points" are nice & dry. WTF?

[Z train]

Bill -

Thanks for the insight with my triple Mikuni's but I'll stick with the recommendation from Todd and Dave on the return setup for my fuel system (that would be the owner of Wolf Creek Racing and Rebello Racing) - thanks for sharing your thoughts though..................

Even those guys can be wrong sometimes.

[Z train]

There's really a lot of mis-information in this thread. Probably should be deleted.

Especially when your post about the "return line in a accident "suggests you know more than the factory.

[sblake01]

Even those guys can be wrong sometimes.

Especially when your post about the "return line in a accident "suggests you know more than the factory.

The word of three guys that 'do it for a living' coupled with the fact that the four vehicles I presently own with electric fuel pumps are 'deadheaded'. Not trying to take sides here but, as they say, I'm just sayin'......

[5thhorsemann]

BTW, I've never had a problem with a fuel pump getting hot, warm to the touch perhaps, but hot, not.

[ConchZ]

Based on my recent experience, seems like a carbed Z needs a return line just to help prevent vapor lock in the fuel rail. Fuel injected rails might be under enough pressure to prevent vapor lock, and thus not need one.

[John Coffey]

Especially when your post about the "return line in a accident "suggests you know more than the factory.

I was disagreeing with the statement that having a return line was safer then not having a return line. My comment was not directed at Nissan's original design.

[240260280z]

From the above it is clear there are pros and cons to both sides.

It also seems to depend mostly on the ability of a pump to have an internal short cycle bypass path, if it sits in the tank, and the pressures and flow rates for the application.

My opinion (old school) for adding an electric pump to a carbed 240z is with Z train, the pump should have flow when on and not be dead-headed so as to minimize strain and to promote removal of internal heat. My opinion is weighted more for longevity of the pump rather than any other priority (safety risks, looks, convenience, etc.).