Lower Pressure Fuel Pumps to supply SU Carbs on a Series 2 Engine~
harder to find the original ones than to locate hens teeth.
What are (if any) cheap common after-market substitute options I might use? what pressure should they output?



hens teeth included.

 

My old 1973 MGB had dual SUs and if I remember the fuel pressure needed to allow them to work properly was 4.5 psi, otherwise they would flood. Today, if I still had the car I would use a modern electric fuel pump with an adjustable fuel pressure regulator, set at 5 - 4.5 lbs.

 

My carbied lump uses a Pierburg low pressure pump https://www.injectorsonline.com.au/p...i-hi-flow.html . Pierburg are OEM manufacturers for many Euro cars (I think there are Carter and Holley equivalents if you like US stuff). My Morris uses a cheap **** made in China Facet fuel pump from Ebay , works fine with reliability being the unknown. I plan to Pierburg-ise the Morris as well and use the other pump for in garage fuel moving eventually.

 

Goss do 2.

GE392 and GE393 from memory, HA, and I THINK the first is 4psi, and the second is 7psi, with the Ltrs/Minute the same, which I dont remember the numbers.

They are both Carby spec pumps.

 

found thee ones at SuperCheap.

Goss Universal Low Pressure Goss Fuel Pump - GE239 - Supercheap Auto New Zealand

look ok? certainly low enough not to flow carbs

 

Thats probably the 392 that Grant was talking about(had all the numbers, just arranged them differently) That looks a lot like the pump I bought for my Morris except with the Goss labelling, the probably all come out of one factory somewere :-)

Should be fine , in can say for sure my single 1960 SU likes it. I'd suggest buying isolating rubbers (rubber blocks with bolt threads out of each end) to mount it. They tend to be a little noisy with a rapid pulsing sound in operation. Mine is bolted to the body work at the moment , its a little loud at but I find the sound feedback reassuring at this stage of that cars recovery. On the road its drowned out by diff and gearbox whine, so all is good.

 

only difference (I can see the two now at SuperCheap) is the flow rate. 3 to 4.5 on one and 4.5 to 6 PSI on the other. wonder if its a case of less is more?

 

I do that when relying on memory these days.

Feeding 2 2" SU carbies I would go for the larger spec pump.

It is flow you need, not pressure as such.

Up to about 5.5PSI is OK for SU needle and seats.

 

Generally forget the aftermarket pumps. just not the same as the original SU pumps. There are many SU pumps that look the same and will fit in place of the original but are NOT the same spec for pressure and flow rate. I have had so much trouble with aftermarket pumps I would not recommend them at all. The car will not run right and you cannot find the problem, it is the aftermarket pump. Get a direct replacement SU pump, they are expensive $150+ but they work and the car runs right. Try Moss Motors first, then SNG Barratt, I do not have good luck with Victoria British on fuel pumps. I assume you have Stromberg carbs with dual fuel pumps and a Left/Right change over switch on the dash. The gas gage float in the tank will also likely need to be changed. A 2 inch lock ring holds the assembly in the tank, turn it about a quarter turn counterclockwise. Use a new gasket when you put it back in the tank.
Good Luck and enjoy!

 

Wow, lots of "fuzz" on that pump. Can that be why you need another?


Were it mine, I'd remove it to the bench, take it apart and clean it up.


Can't hurt and at least a decent chance of success.


Carl

 

Has more to do with pressure than flow. Its easy to overpower the floats in the SU carbs and they will flood / run rich (then flood). Crucial that the float height is within spec and carb jets are super clean. I tried a higher pressure pump on my 73 MGB and had nothing but trouble (flooding) went back to old SU pump with points ,..cleaned it up and it ran pretty good .. when it did not... I gave the pump a slight tap with a wrench and it would run again until... finally got tired of the hassle and sold the car.

 

Two points to add to the discussion:


1. Way back when, we relied on Stromberg 97's or 94's on our
multi carb'd flat head Fords. Always prone to flooding. No pressure regulators then. Output from the mechanical pumps was erratic.
Length of the operating shaft critical.


My last old Ford project was in about 95. Wow, new tech, electric
fuel pump and pressure regulator. I got two 94's to run just fine, sans flooding. Three not so much. Sold in the midst of adopting a progressive throttle, over all at once.


2. I was trying to remember the name of a popular maker of fuel pumps and related. Walbro!!! Google it for an application.


Carl