Hey guys,

I'm running a supercharged 1275 with an HIF44 in my current build. I'm just trying to work out the specific fuel setup as I'm installing all hoses and pipes first while I can get to them. (I see the other fuel thread but I didn't want to hijack it with a different set of questions).

Is the square Facet pump a good solution or do you recommend something different?

Is there a specific PSI I should aim for?

Should I run high pressure to the engine bay and then step down to just a few PSI just near the carby (as Vizard recommends)?

And should I setup a return line or just have the normal single line going to the carby?

Also should I just use the standard solid fuel line from tank to engine bay or do you recommend something bigger?

I'm not really sure how those fuel pumps work which doesn't help - as in, does it pump until the desired PSI is reached, then cut out until the PSI drops again; or do they constantly pump even when the carby closes the float;

Cheers
Morbo

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Build thread for Supercharged 1275 1967 Deluxe Resto
Build thread for Mini ute conversion 998cc Turbo

Hans the supercharger guy tells me that the max pressure the HIF SUs can handle is around 2.5psi.

So that seems to tip the scales in favour of an electric pump through to a regulator in the engine bay to drop it below 2.5psi.

Still not sure if I need a return line though. Seems like I won't maybe?

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Build thread for Supercharged 1275 1967 Deluxe Resto
Build thread for Mini ute conversion 998cc Turbo

Hi,
I had a problem with the return line when I had the supercharger fitted to mine. Car wouldn't run for any length of time, so I disconnected it. Ran fine after that.

Okay sweet thanks Dennis.

I'll run an electric pump, make sure the pressure is 2.5psi or below when it meets the carb and I won't run a return line.

I'll see how that goes

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Build thread for Supercharged 1275 1967 Deluxe Resto
Build thread for Mini ute conversion 998cc Turbo

Its not so much the pressure to the carb, but the flow rate. The pressure is there to ensure that an adequate flow of fuel is provided to the float bowl. Once the fuel is in the fuel bowl it is independent of the fuel system pressure. On a N/A carb it is at atmospheric pressure. If the pressure drops away at high load/rpm, then your fuel pump may not be up to providing the flow rate, or the line to your carb is unable to keep up with the flow required of it. Vizard speaks of this through the conversion of fuel lines from 1/4 I.D to 5/16ths.

So watch the fuel pressure once you start using your car at high speed and under load. If it drops away, then consider changing you pump, upping your pressure, or changing the fuel line out.

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SooperDooperMiniCooperExpertEngineering

All garage work involves equal measures of enthusiasm, ingenuity and a fair degree of irresponsibility.

I have a silver top pump mounted on the rear subframe at the same location as the Cooper S pump and malpasse pressure gauge in the engine bay as recommended by VMAXSCART .
And I am using standard gauge fuel lines, I didn't upgrade apart from using fuel injection type hoses.
When dynoed we set the pressure at 3psi and it seems OK.

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1969 Cooper "S"
1967 Mini Deluxe
1973 Clubman Van (the fleet spare)
1978 ex 1275 LS ("Wizard" Eaton Supercharged)
2015 HSV GenF GTS(occasional drive & tow car)
2019 MINI F55 Cooper S