Refitting Mechanical Fuel Pump

[ham204]

As the title says, I'm removing the electronic fuel pump fitted by the PO and refitting a mechanical pump. The Parts catalogue says that the part number for the gasket to the pump is UKC8523 which is about 1/2 inch thick. Rimmers says this part is for the 1300 and 1500, the gasket for the Sprint being the thin one.

So who's right? I have to say that fitting the pump with the thin gasket proved to be very difficult

[Flyfisherman]

As the title says, I'm removing the electronic fuel pump fitted by the PO and refitting a mechanical pump. The Parts catalogue says that the part number for the gasket to the pump is UKC8523 which is about 1/2 inch thick. Rimmers says this part is for the 1300 and 1500, the gasket for the Sprint being the thin one.

So who's right? I have to say that fitting the pump with the thin gasket proved to be very difficult

All depends on which fuel pump you have as there are two varients.

One pump has a longer crank arm than the other pump - if you purchase the pump with the long crank arm you require a spacer (UKC8523) + two paper gaskets short crank arm no spacer but you will require one paper gasket -see attached for pictures.

http://www.rimmerbros.co.uk/Item--i-GRID008455

[ham204]

This is what I bought over ebay.Its a QH but doesn't look like either of the two Rimmer 'Sprint' fuel pumps!

[marko]

Why did the pumps have different length arms? Were they to fit different camshaft drives? I need a new one but am unsure which one to order.

[MIG Wielder]

The diagrams on page 1K 10L of the 1981 parts book explain a lot.
Early 1850s and Sprints were fitted with a 312167 fuel pump. This is commonly referred to as the "short arm pump". It was fitted with a single thin gasket.( But note that the workshop manual refers to adjusting the fuel pump pressure downwards if neccessary by fitting extra gaskets. )
Later 1850s and Sprints were fitted with a TKC3419 ( = RKC5051 ) fuel pump together with a 13mm plastice spacer block part number UKC 8523. This is referred to as the " long arm pump ". The spacer block moves the later pump furthur from the mating face on the cylinder block to give the same pump pressure.
They give the change point as "May 1978".
I've taken a sample of each pump and drawn round the operating-lever profile of each pump.
1 Is the early slant 4 pump, which is actually a QFP32 QH version
2 Is a later slant 4 pump, QFP33 QH or 17110029 for a genuine AC pump.
3 Is a later slant 4 pump, with the spacer block fitted.

A genuine A.C fuel pump for the early slant 4 cars has 7990047 stamped on the operating lever.
A genuine A.C fuel pump for the later 1850 / Sprint cars is stamped 7990487.

If swapping from early to late fuel pumps you have to change the fixing bolts as well.
Early (short ) are 149673 x2
Late ones (long) areSH605101 x2

In each case the mating face of the pump is on the LHS of the graph paper.
Try printing this out at various scale factors to get the 50.00mm scale I've drawn in at the top.

Now 1300s and 1500s are different again.
Early 1300/1500s have RKC1624 pumps
There is no mention of what later 1300s have but later 1500s have an RKC5049 pump ,.longer studs TE605041 and this UKC8523 spacer block. The profile of the 1500 pump lever is very different to the slant 4 item.
Slight problem is the spacer block is NLA so its going to be EBay or similar.

And yes I've got caught out with a so-called "genuine Sprint long arm fuel pump ". It is similar but not close enough and has a different number stamped on the operating lever.

HTH,
Tony.

[ham204]

Wow, migwelder, what a lecture! This should be pinned somewhere on this forum

If the spacer block is 13mm wide, then Rimmers have it

[Flyfisherman]

Nice one Tony - I was trying to find an item that you had written about various fuel pumps

viewtopic.php?f=4&t=27865&hilit=sprint+fuel+pump

Paul

[marko]

So both the fuel pumps work on a 1500 only you use the spacer block with the long arm?

[mahony]

Don't know why you would replace a electric pump for a mechanical one ( unless it's a concurs car and it's for originality), got rid of the mechanical pump 20yrs or so ago because of all the faffing about with different pumps and different arm sizes, no more cranking for me to fill up the fuel bowls and much more reliable

[ham204]

Don't know why you would replace a electric pump for a mechanical one ( unless it's a concurs car and it's for originality), got rid of the mechanical pump 20yrs or so ago because of all the faffing about with different pumps and different arm sizes, no more cranking for me to fill up the fuel bowls and much more reliable

It has to pass a classic car test in Malta, where it is now based) and a ticking fuel pump won't do my chances any good......

[mahony]

Don't know why you would replace a electric pump for a mechanical one ( unless it's a concurs car and it's for originality), got rid of the mechanical pump 20yrs or so ago because of all the faffing about with different pumps and different arm sizes, no more cranking for me to fill up the fuel bowls and much more reliable

It has to pass a classic car test in Malta, where it is now based) and a ticking fuel pump won't do my chances any good......

In that case good luck with the pump

[cleverusername]

I manged to find a new spacer block, I think it was for a Spitfire. It fits and it seems to be the right thickness for a Sprint.

[ham204]

I manged to find a new spacer block, I think it was for a Spitfire. It fits and it seems to be the right thickness for a Sprint.

How thick is it?

[Flyfisherman]

I manged to find a new spacer block, I think it was for a Spitfire. It fits and it seems to be the right thickness for a Sprint.

How thick is it?

10mm

Paul

[dollyman]

The mini spacer fits as well https://www.ebay.co.uk/itm/Mini-Fuel-Pu ... SwnjZcHOHU

Tony.