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Plastic tanks, fuel outlets, external pumps
SkinnyG - 21/1/06 at 05:15 PM

What is the consensus on mounting the fuel outlet on a plastic tank with an external pump?

I'd like to mount it on the top with a tube inside dropping to the bottom of the tanks to act as a pickup, but I'm not sure if the pump can lift the fuel.

If I mount the outlet on the bottom of the tank, it's easier for the fuel to get to the pump, but I'm afraid of leaks.

Thoughts?

Greg
"I'm from Canada. They think I'm slow, eh?!"

stevebubs - 21/1/06 at 05:21 PM

what type of pump? A facet red top or similar will be fine with this....

[Edited on 21/1/06 by stevebubs]

britishtrident - 21/1/06 at 06:01 PM

quote:
Originally posted by SkinnyG
What is the consensus on mounting the fuel outlet on a plastic tank with an external pump?

I'd like to mount it on the top with a tube inside dropping to the bottom of the tanks to act as a pickup, but I'm not sure if the pump can lift the fuel.

If I mount the outlet on the bottom of the tank, it's easier for the fuel to get to the pump, but I'm afraid of leaks.

Thoughts?

Greg
"I'm from Canada. They think I'm slow, eh?!"


Pump should be as low as possible to avoid vapour locks --- it won't make much difference as regards leaks. When you pump fuel the suction side of the pump gets sub-atmospheric pressure this can lead to flash vapourisation or cavitation in the pump particularly in hot weather --- as result the fuel system gets vapour locked. If the pump is located low down it has a static head of pressure at inlet making problems of this type much less likely.

Choose a pump with an output pressure that matches your fuel system --- ie don't fit a high pressure pump if you run carbs.


[Edited on 21/1/06 by britishtrident]

SkinnyG - 21/1/06 at 11:45 PM

Okay, perhaps a bit more info may be needed.

I am running a 4A-GE with OEM Fuel Injection. I have a plastic fuel tank. I want a low presure pump to fill a surge tank (swirl pot?), which in turn feeds a high pressure fuel pump to run the injectors. The injector feed will return to the surge tank, and the surge tank will return to the fuel tank.

I'm just concerned about drilling a hole in the bottom of the tank to feed pump #1, and never getting the fitting to seal properly again.

G
http://www.gwellwood.com

JB - 22/1/06 at 08:19 AM

You need to use a plastic washer either side of a union in a plastic tank. I have used plastic tanks twice and have not had any leaks.

This webpage may help.

http://www.beardmorebros.co.uk/website%20pages/update_10th_July_2003.htm

John

britishtrident - 22/1/06 at 12:51 PM

The suction tube can go in from the top but keep the pump low, also restrict the return line to the tank -- 3/16" brake pipe should be OK for the return.