Stewart-Warner 240A fuel pumps

[John Shand]

Hi Trevor

yes I had thought about that, and wonder in practius if it would make any real difference depending on what frequency it was set to as the spring does the pump and the pulse just returns the plunger, I may do a test anyway,

the other option is similar to your prox sensor, I would use a hall effect to pick up where the plunger was and triger the coil ( a soild state switch with histereasis) however you spell that word

what are they like to seal? as fuel must be present round the coil, or is mine missing something?

 

[Jim Rosenthal]

SW is officially not interested in putting these pumps back into production. Whatever. I wish they were but we'll all have to look elsewhere.

 

[Trevor Booth]

John,
I made an aluminium plug that took the place of the switch. I made a cap to hold it in via the three studs as the switch is normally retained. I used a threaded prox switch and inserted it into the plug, I sealed the prox switch with a fibre washer and lock nut on the outside. I could then adjust the prox switch from outside. The wires coming out from the coil connected by the normal tubes to two "studs in the plug. The studs protrude thru the plug to connect wires on the outside.
The issue I had was the field around the prox switch sensing the piston rather than the groove in the piston. Modifying the piston would have solved this.
You only need to "fire" the piston when the piston has finished its stroke. The piston speed and cycle rate are controlled by the fuel flow i.e. the rate of fuel usage. The piston self adjusts its cycle rate. You cant do this without a prox switch.

 

[John Shand]

John,
I made an aluminium plug that took the place of the switch. I made a cap to hold it in via the three studs as the switch is normally retained. I used a threaded prox switch and inserted it into the plug, I sealed the prox switch with a fibre washer and lock nut on the outside. I could then adjust the prox switch from outside. The wires coming out from the coil connected by the normal tubes to two "studs in the plug. The studs protrude thru the plug to connect wires on the outside.
The issue I had was the field around the prox switch sensing the piston rather than the groove in the piston. Modifying the piston would have solved this.
You only need to "fire" the piston when the piston has finished its stroke. The piston speed and cycle rate are controlled by the fuel flow i.e. the rate of fuel usage. The piston self adjusts its cycle rate. You cant do this without a prox switch.

I had not considered the magnetic feild from the coil, back to thinking, may be optic sensor?
good to see you gave it a fair go

John

 

[Trevor Booth]

John,
that was about 15 years ago, there has been some development in prox switches and they are now much smaller down to 3mm, the one I used was 8mm, I reckoned that the groove in piston need to be wider to get a 'stronger" difference in field. A smaller dia prox would be not so susceptible possibly.

A distance measuring photoelectric sensor may work wherein they "reflect" a beam back. try balluff

another thought how about a plunger with a spring loaded ball on the end of it

 

[Randy V]

Gents - I bring good news!

I've thrown caution to the wind (so to speak) and carefully disassembled a non-functioning 240A Switch. Proper cleanup and lubrication - re-assembly and it works like brand new...

I have taken a lot of pictures and am in the process of documenting the process. I'm certain that anyone could do it and the failure mode that this switch was in was identical to the others I've had that were failed;

Connect 12 12v and nothing or connect to 12v and a single "thump".

Stay tuned - I will make this a separate post/thread.

 

[Trevor Booth]

Randy.
like I said just needs patience some TLC and you can fix 'em

 

[Rune]

Does someone know where these pumps normaly where used exept in cars ?, I'm in the marked for getting two pumps for my mono, but when the seller (on Ebay) only sell to united states , I'm out of business to get pumps.
I must also try to find some i Europe, and I belive that I have read that there are some industrial maschines that used these pumps. It does not look correct in the engineroom without them

 

[Charlie Farley]

Guys,

You may or may not know that i have had the gasket and seal kits remanufactured. Also the black top rubber boot.
The replacement switch is quite some way down the line in development.
I'm hoping to receive the prototype before christmas.
I can tell you its been a hard slog so far, to get it to work in the same way as the original.
I've no prices for the switch yet, but will get back to you as soon as i have more info. I guess that price as always will come down to the volume i order.
These small scale productions are never that cheap.
If you want to email me try [email protected]

 

[John Shand]

Does someone know where these pumps normaly where used exept in cars ?, I'm in the marked for getting two pumps for my mono, but when the seller (on Ebay) only sell to united states , I'm out of business to get pumps.
I must also try to find some i Europe, and I belive that I have read that there are some industrial maschines that used these pumps. It does not look correct in the engineroom without them

They came out in Hough loaders and International combine harversters in New Zealand

 

[Jim Rosenthal]

Well, I am now the proud owner of four of these things, courtesy of eBay. So now I am going to look them all over, once they've got here, and learn to repair them. I only need two, but from what I've read, the switch repair isn't that easy and I may screw one up learning how to do this.

I could use a readable-size copy of the pump instructions and any other documents anyone has for these. Once I get it apart, maybe I'll understand how it all works a little better.

 

[Randy V]

Jim - Check the tail end of this thread (I just updated it)
http://www.gt40s.com/forum/gt40-tec...240a-fuel-pump-switch-renewal.html#post278418

If you have any questions or need some help let me know..

Oh yeah - and quit bidding against me! :laugh:

 

[Jim Rosenthal]

I printed these. One of the four pumps I bought is already disassembled- which means I can't do it any more damage, can I? So I am going to look at that one, first, and figure out how it all goes together. Then I am going to start looking at the other three and figure out now to overhaul them. And put them all back together so that they work right.

 

[Randy V]

Good luck with it Jim... I would say that the most delicate parts are the connection tubes in the switch assembly. Let me know if you should need a hand.

 

[Tommy]

Hi Jim,

if theay built these pumps i will take four pieces for me and
50 pieces for the club-friends in europe.
If there is a chance to get them please give a sign. :thumbsup:

Best wishes, Thomas.

 

[Jim Rosenthal]

There's no chance. They threw away all the tooling etc. Best source would be Charlie Farley on this forum, he has some and he knows how to rebuild them so they work and don't leak, which is a big plus.

 

[arroyo grande greg]

Hi all. I'm also ready to rebuid a few pumps: refurb one I've had on my Cobra replica and a couple of old spares. I Also have 2 pristine never used NOS pumps from many years back that were freshed up by Motorsports International a few years ago and are perfect and I'll probably never use.
But back to rebuilding - has anyone found a source or replacement/alternate fuel filter for the 240A's???????
Andy Booth is my go to guy for gaskets and seals.
Look forwar to any info.
Thanks and what a great forum.

Greg

 

[Jim Rosenthal]

Yes, Andy Booth found some of the filters over here in USA, email him for exact description and item number etc. I think they were made by Baldwin, but I am not certain.

 

[John Shand]

Hi I have found a NZ made piston pump (same type as SW) that will fit inside the SW240
housing with a small amount of machining and they are all electronic, no switch contacts
to give trouble, with a o ring top and bottom the unit is sealed and the power cable comes
out the original fitting, the best of the old and new, I am going this way because of leaks
round the switch (I don't wan't a fire) and availability of the switch unit is a problem,

will post a photo when done if there is interest

John

 

[Charlie Farley]

John,
I've solved the leaky switch aspect, by having the unit remanufactured.
It features an aerospace spec seal from DuPont.
Also i located a box of NOS Fuel Filters, so they are available.
Just email me.