Just wondered after just picking my new fuel tank up. Where's the best place to put the pump?At the engine end or the tank end and why?

Carb or FI pump - makes a big difference. Also some pumps are designed to suck from the tank. Some to force fuel down the fuel line.

A FI pump (such as the Bosch I have now on the Zetec) should ideally be cited near the tank, below the level of the lowest part. They prefer to push fuel along the send line at a pressure and have little restriction on the inlet.

I had a facet electric fuel pump on the xflow and the fitting instructions state that it could suck fuel up to a 12" height from the base of the tank. I fitted it at the rear as it was tidiest.

[Edited on 9/7/07 by SeaBass]

Carbs sorry. ZX9.

Are you using the original fuel pump from the bike then? I would aim to fit it in a similar position to the bike in terms of the level above or below the tank. IMHO it would work better pushing fuel to the front of the car but I'm no BEC expert.

Yep am using original pump. Its a good sucker. Started the engine with fuel in a plastic bottle and it just collapses the bottle in nae time.

I am running a Blade fuel pump (now!) and I have it mounted on my engine cradle, then a few inches to the fuel filter and then a few more inches to the carbs.

Runs perfect...

hth
Steve

Conversely I ran a blade carb pump from the rear of the car near the tank with my blade engines for about 3 years and that also ran perfectly, so I don't think it matters too much, at least not with bike pumps.

Always no matter what the type of pump as near to the tank as possible and low down.

*** No such thing as suction **** all you are doing is reducing the pressure to below atmospheric and letting atmospheric pressure and "head" of liquid drive the fuel into the pump.

If you try and draw any volatile fuel through a long pipe in hot weather you run the danger of vapour lock problems.





[Edited on 9/7/07 by britishtrident]

My carb'd R1 pump is fitted on the lower chassis rail of my Striker in the engine bay (below the bottom of the tank). It's done about 6500 miles and many track days without a problem. So long as it's below the tank it'll be fine!

Most put the pump near the tank as then it's pushing not sucking. Only trouble is then the entire fuel line is under pressure.

I've got mine at the engine end with no problems but it depends on your pump......

Sounds like its 6 of one and half of 12. Was thinking of saving work in extending the power lines.

I would have thought, unless the feeder pipe to the pump is a bigger bore than the feed to the carbs/injectors that it would also be under pressure as the pump would need the fuel to be comming in at the same rate as its forcing it.

No it isn't a 50/50 situation.

Fuel line to pump will be under negative pressure (ie below atmospheric) if the pump is above the level of fuel in the tank, any restriction in the line to the pump will make this situation worse.
If the line gets vapour lock the fuel won't get pumped.
Volatile fuels need a positive pressure to prevent them flashing off to vapour in the fuel ine and pump body

[Edited on 10/7/07 by britishtrident]