MG-Cars.net

Welcome to our resource for MG Car Information.

Recommendations

Parts

MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG Midget and Sprite Technical - Twin fuel pumps

My hillclimb Sprite has a 7 litre fuel tank in the boot with a Facet pump next to it feeding a fuel line similar to the original set up. Obviously this is a bit limited for road use (made it to midget 50 though!) so I am thinking of plumbing in my old 20 litre tank for longer trips. This tank fits under the car in the standard position so I was thinking of keeping the tank and pump I have in the boot and having the larger tank and another pump under the car. My question is this, will it be ok to have two pumps (I'd probably only have one running at once via a switch) feeding the one fuel line with a 'T' or 'Y' piece? Or would it try and pump fuel back through the non running pump or damage it in some way?

I am thinking it will be ok but maybe someone could confirm this before I start drilling more holes in my car!


John Payne

Why not have the "T" or "Y" piece before the pump with a tap in both hoses so that you can switch between tanks but only have the one pump (or am I being daft here)
Gary & Gaps

John.
I have Two pumps connected in series, one just pumps through the other, with a Two way switch, so that both cannot be on together. I use the original SU pump, with a Facet back up. It works a treat, and I can use either pump.
This was the result of a very frightening breakdown on the M25.

I got the idea from David Liebs site for the MGB.


Dave Barrow

Dave,
I have done the same but fitted the second pump under the bonnet. I had a similar problem breaking down on a blind bend I thought I would be able to coast round, but didn't. repaired the old pump and have not had any problems since.
Mike
Mike J Pearson

Hi John long time no hear. :)

On my MGA I have had 2 pumps (SU and Facet) since I finished it some 10 years or so ago. They are piped in series and both have an independent switch.

I have recently equipe my Midget with twin pumps, one is a high pressure pump for the turbo application and the second is a facet cube for a get me home job if the injector pump fails. They are in parallel as both have non return valves anyway and are operated from a changeover switch

Both systems have no problems and can only give benefits I believe
Robert (Bob) Midget Turbo

John, I'm not sure if any of the foregoing is of direct help as they don't seem to have two tanks?
To try to answer your Q it will depend if you have any non-return valves fitted and if so, where. If there aren't any then yes one pump will tend to push back through the other *maybe*
David Smith

David I think both the facet and the SU have non return valves as standard internal, (otherwise they would not work?)
Robert (Bob) Midget Turbo

Correction
I should have said Dave DuBois website for the MGB second pump. Teach me to write without doing the research.

Dave
Dave Barrow

I'm glad you came in with that one David as that was what I was thinking! I would think having both of them running at the same time would be ok but then when the top tank emptied it would just be pumping air. Or it could be as Bob says (I must come a Lincs meet sometime, Bob!) and the pump would act as an NRV?

My original idea was to have the top tank outlet connected to the bottom tanks vent point in effect a 'gravity' tank. Then just have one pump from the bottom tank.

I know all this sounds like a lot of trouble!! I want to end where I can have a reasonably long range set up but then be able to quickly remove the larger tank for competition use. The small tank allows me to run with only about 3 litres of fuel on board.
John Payne

John. David DuBois's retirement business is the rebuilding of SU fuel pumps. He is very knowledgeable about such things and does good work. He has a website which can be found using a Google websearch, and the website has a contact function. I have known him for a number of years and have, always, found him to be helpful. You have a specific problem, wanting to be able to feed from two fuel tanks each of which you think might need a separate fuel pump. Why not contact Dave, outline what you are trying to do, and ask that he post a response to this thread?

Les
Les Bengtson

This thread was discussed between 26/08/2011 and 27/08/2011

MG Midget and Sprite Technical index

This thread is from the archive. The Live MG Midget and Sprite Technical BBS is active now.