smal and large fuel tank

[UweM3]

while installing my swirlpot in the boot and testing my intank pump I was wondering if the larger 63ltr tank would fit without problems.

Does anyone know exactly the difference is between the 55l tank and the 63l tank? Is there a difference between the fuel pump assy's or is the tanks pump opening the same for all?

I think buster has fitted the E36 M3 ful pump in the E30 tank but looking at my fuel pump assy (I have the lifter pump) I can imagine that must be a real tight fit.

[jaistanley]

I fitted the E36 3.2 pump into my tank Uwe... I had to remove the actual pump from the E36 housing and chop the E30 about to fit. I have pictures, but not here on my work computer. I'm thinking about swapping back to an E30 pump later to use as a lift pump and submerging the E36 one in a home made swirl pot. I need to see how bad the fuel surge will be first.

I can't imagine why a 63L tank wouldn't fit your car. You might have to get a pre-facelift one if they are different on the M3.. I'm not sure.

Jai

[DaveD]

ran a compatibility on oem and it confirms that the larger fuel tank (16111180175) was fitted to the m3 ....at some time

[DanThe]

I fitted a facelift 63 litre tank to my early car, the only trouble you will have is the external pump mounts, I bent them over a touch and the tank just about slotted into place!
The sender/pump opening is the same on all tanks, the extra capacity is on the Left Hand side of the tank

[UweM3]

Brilliant Dan, thanks a lot. Do I understand this correct, the external fuel pump assy is in the way for the larger tank?

DaveD, the larger tanks was fitted to the SPORT EVO M3 which I believe is 1989 model (delievered in 90)

jai, you will only suffer fuel starvation on track, for a road car you might be just fine. Raise my hat to your effort of fitting the EVO pump in the tank!
I never had problems, it all started with R-Compound tyres and stiffer suspension and tank below 1/3

[Brianmoooore]

55l and 62l tanks are completely physically interchangeable, but you must use the fuel return stub on the side of the tank, or you won't be able to use the fuel in the LH side.
62l tank has an extra hole on the top for the LH fuel level sensor, and the car needs a different fuel gauge to suit.
62 litre tank suffers less from fuel starvation on long LH bends, because it doesn't have the link pipe that allows the fuel to migrate to the LH tank.

[DanThe]

You mean right hand bends Brian,

I assume the pump would be in the way Uwe, it may just squeeze in, all I know is that it was a c*nt to get past those mount tabs!
Will have a look later

[jaistanley]

Here's what my pump looked like before fitting...

[UweM3]

Here's what my pump looked like before fitting...

looks completely different to mine. I only have the tiny lifter pump and the pressuring pump is (or better was) in front of the LH rear wheel.

[Jhonno]

I think that is already transplanted into the E30 cradle Uwe

[DanThe]

Before fitting = after modding

I used an eBay Walbro-like pump

[UweM3]

I think that is already transplanted into the E30 cradle Uwe

the most important thing for me is the fact that the different in tank pump assy's from the E30 can just be swapped. If I find that my lifter pump isn't up to the job I can use a face lift pressure pump to feed my swirl pot.

[Theo]

Let me know how you get on with that. I intend to use the M3 in-tank lift pump to feed my swirl pot, but not certain it will be sufficient.

That said, my H36 has the standard e30 m3 pumps and that has fed 330-350?bhp for 18 years.

[UweM3]

Let me know how you get on with that. I intend to use the M3 in-tank lift pump to feed my swirl pot, but not certain it will be sufficient.

That said, my H36 has the standard e30 m3 pumps and that has fed 330-350?bhp for 18 years.

don't hold your breath Theo, don't know when I am finished.