2 fuel pumps in series

Hello XK enthusiasts!

Sorry I have no question but a small story and a solution (not for the purist) to share with you.

On the German highway the fuel pump broke, after 1 hour changing de pump on the shoulder (I have always a spare with me) the ride can be continued.


It is not a pleasure to-do a repair on the shoulder of a German highway, and beyond that it is very dangerous and not allowed.
I keep thinking of a solution with to fuel pumps in series (parallel is also possible but series is easier). I started my research on the WWW.

Started with a Facet Posi-Flow 60104 (1.5 – 4 Psi). After installation I make a test drive.

Results:
With the Facet Posi-Flow working max. speed 60mph (100kmh)
With the SU AZX1307EN working max. speed 90mph (140kmh) resistance from Facet pump limited it @ 90mph.
For emergency it’s OK. Faster than 90mph I don’t drive and in case of a broken SU-pump is 60mph enough to get in a save area.



But I was not satisfied with the results, knowing that the max. speed is 90mph (that I never drive J).

In the mean time I repaired the pin/switch from the broken Hardi pump, I get the pin/switch free of charges from Hardi Germany.

So I change the facet Posi-flow for the Hardi pump.
Results:
With the SU AZX1307EN working I stopped @ 100mph (160kmh)
With the Hardi-pump working I stopped @ 100mph (160kmh)
Those results are fine for me :smile:


The switch to choose which pump.


End of my story.

Best Regards,

4 Likes

I think parallel is harder.

My replica D has two square pumps in parallel fed from opposite ends of one tank (no starvation in long bends with low fuel). The plumbing connection was a T into a single line forward to the Webers but I changed to a Y so the pumps will not oppose each other so much. I was thinking of a switch to power one pump at a time to have back up but kept it original. I will fit a mechanical reserve tap somehow because the is no fuel gauge…

Fuel pump repair alongside an American expressway would not be all that much fun either; even on a suburban street, as happened to me yesterday; there seems to be very little forgiveness for broken down cars these days.
Another possibility is a double pumper SU, as was used on the carburetor model XJ12 before 1975. This would be a parallel system.
BAC-408

2 Likes

Many years ago, I read in a column Shel Silverstein wrote in Playboy Magazine about the horrible experience he had when his brand new Rolls Royce quit on the Brooklyn Bridge on the way home from work, blocking one lane of traffic. He said people shouted some pretty mean things at him.
Mike Moore