Fuel systems

[Bernd Felsche]

Ade + Lamb Chop tapped away at the keyboard with:

> I am in the process of putting a honda ZC engine in my mini. The 
> mini is carbureted with a mechanical fuel pump on the engine.

> The honda has a high pressure pump (35-50psi depending on year of
> car with the vac hose disconnected from the regulator) in or nr
> the tank. This goes up to the fuel fuel rail which has a regulator
> on it.. the reg dumps excess fuel back to the tank to maintain the
> pressure.

> I am just wondering the best way to do the fuel system. I don't
> really fancy having 50psi fuel lines floating around the length of
> the car. 

Well, staple them down. :-) Also, I didn't realize that a Mini had
"length". >:-)

It really isn't a problem if the fuel cutoff on engine stall works
correctly. You can even add in a pressure switch at the pump so that
if the outlet pressure of the fuel pump goes below a pre-determined
level, that the pump cuts out. That would only be enabled after the
engine has been running, of course!

Just take care that the fuel lines aren't located where they're
vulmerable to being hit by debris, torn in a crash or toasted by
engine/exhaust. Many cars use polymer fuel lines because these are
more resistant to damage; they won't fracture or crack as easily.

> Can I have a low pressure pump nr the tank then a high pressure 
> pump in the engine bay? What should I do with the return line? can 
> I run this to the inlet of the high pressure pump or do I need to run 
> it back to the top of the tank?

You want another fuel tank in the car?

The return line should go into the tank. As discussed earlier, the
fuel that's gone through the rail has been heated by the engine and
you're better off drawing cooler fuel from the tank, least of all
because it's more dense.

-- 
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