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MG Midget and Sprite Technical - Fuel pump recommendations - positive earth?

fuel pump recommendations please.

I have a 948cc MkII Sprite, positive earth, with LCB exhaust manifold. Currently it has an SU fuel pump of uncertain type and origin (may or may not be a puller pump) in the engine compartment installed by the previous owner (presumably as no clearance for the orginal engine mounted mechanical pump) and a plastic fuel filter before the pump; it was tired/damaged and I rebuilt it a while ago with a service kit and a secondhand Bakelite points mounting cradle to replace the cracked one - it has now died and I want to replace it with a new pump - any suggestions please?

My preference is to buy a new SU positive earth pump (still points) - part number? - but mount it close to the tank in pusher configuration using a later Sprite mounting bracket and put a Filter King in the engine bay. Currently standard engine (or very mildly modified) running on twin HS4 SU carbs but will want something that will be suitable for current engine, modified 948cc or a 1098cc (or 1293cc) that could go in later. I hear talk of an aftermarket ’Hardi’ pump for later neg earth cars; a solid state noisy cube Facet is probably not required at the moment (but could easily be used later close to the tank) and a silver or red top Facet would be massive overkill flooding carbs without a Filter King unless I somehow had 160bhp plus under the bonnet!

Whatever I use will need to be capable of being isolated for motorsport events.

Cheers
Mike
M Wood

Mike,
As I understand it the Hardi pump can be configured as positive or negative earth.
I have installed one recently and am pleased with it so far having had 3 SU’s fail with hardened diagrams due to the latest brew of fuel available!
Hardi state that theirs can cope with all of the new fuels.
Not sure why you reject electronic pumps as they have been fine for me.
Check e bay for best prices - certainly not the big suppliers !

R.
richard b

I use a Facet silver top mounted in the rear on my Frogeye. I have a pressure reducer feeding twin HS4's
The pump is isolated from the chassis by the two rubber cotton reels supplied so is configured for positive earth. 10 years running and no problems at all.
Bob Beaumont

SU pumps now dual polarity, they use a bi-directional diode to shunt any voltage across the points in excess of about 25V leaving minimal spark. That make the points last a lot longer than the original 50,000+ miles.
AUF214 for pusher pump with push-on fittings 15 gal/hour free delivery
AZX1307 for pusher pump with banjo fittings and 20 gal/hour free delivery.
Capacities as measured by me at the carbs with the hose disconnected and directed into a container.
Paul Walbran

The ordinary SU electronic pusher is fine, and I would not go back to points. But if you get one, take the top off, remove the grub screw that holds the Hall effect magnet, and put it back with thread locker. It fell out of mine last year a long way from home.
Les Rose

Les,
I converted one of mine to electronic years ago and it notes that once in correct orientation to remove grub screw and apply thread lock adhesive replace and tighten.
I wonder if yours was a manufacturing defect - not carrying out their own procedures ?
This is dated version 3 02/03.
My only issues are the diaphragm hardening and stopping the pump operating.

I have made a new rod and diaphragm assembly utilising the original steel/iron jumper with replacement diaphragm material and it seems to work ok. Not fitted as I bought the Hardi.

The SU replacement diaphragm comes as a unit and costs minimum of £30 !!

R.
richard b

Having bought a number of Burlen products over some years namely Amal gas injectors I've found the assembly quality to be somewhat variable. They're are a minor part of their product range acquired along with the Amal carb stuff. They're not supplied fully ready to use in that you have to block 1 port and attach a gas supply to another but have the jet and adapter fitted and they may or may not have sealant applied to the jet and adapter and may be loose or done up so I learned to always check and rectify as required and the standard jet supplied needed changing anyway.

https://amalcarb.co.uk/amal-gas-injectors.html
David Billington

This thread was discussed between 03/06/2023 and 06/06/2023

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