The V8 Owners Forum -

hi guys, jsut need help with a few problems i bogut ha v8 fitted it to the mini all piped up so far now im to the carb. i want to fit a injection fuel pump but i think it might be to powerful so im gnna fit a regualtor any 1 tell me best pressure to set it? also is it a single fuel pipe in and no return? a pictures with what goes were would be great thanks

Hey Mini
You will need a fair old regulator to come down from injection pressures to carb pressures.
You need to set the 500 to 5-5.5 psi running.
Single feed in,but don't see why you can't run a return if you want to.
cheers
Paul

A Facet Red Top would be a better choice and a pressure regulator set to 5-5.5 psi as Paul suggested.

Kevin

just run a straight carb pump, there is absolutely no point in running an injection pump and restricting the pressure down. Reducing something that is meant to deliver pressure at around 40 psi down to 5 psi is a waste of a pump.

I agree with all of the above,

Also running high pressure in the fuel lines when there is no need is increasing the risk of a leak when there is no need.

Finally I don't like regulators anyway, one bloke on the Cob forum had problems with a WOT lean out because the regulator was not only reducing the pressure but also the total volume of fuel being delivered.

This handy formula works very well and helped prove that his regulator was knacked:

Fuel required in CC per minute = BHP x 4.7

So if your lump is expected to make 300 BHP then you will need the pump to deliver 1410 cc in one minute. (I'd want the pump to deliver at least 1800 cc to be on the safe side) This is an easy test to carry out and could save you a whole load of grief!