Stewart Warner 240A fuel pump

[mlplunkett]

Wow, what a treasure trove of info. I found nothing online for parts kit searches but am waiting for reply from "Sam" at Cobra Performance so I'll pass on whatever I find out. I have 4 pumps that I haven't disassembled yet so I don't know what parts I need but I figured there was a standard set of parts that you always replace once you go to the trouble to tear down an old pump.
So what's the story on single vs double pump application? Did the single pump on the trunk lid bracket have priming problems? Was the double pump setup a race track modification? I notice two different plumbing arrangements in the examples. Bob's photo shows the pumps plumbed in series (outflow from pump #1 goes to inflow for pump #2) while the fittings for the other photo looks like it's set up for parallel plumbing (inflow from tank is split going to both pumps and outflow from both pumps comes together on it's way to the motor). Seems like both would work fine but is one more original than the other?

[gt350hr]

    Earl,
      Yes I have seen the "dual" installation as well , just like Bob's photo. "Most" were plumbed "in series" from SAI. The drag race Mustangs hung them on a bracket under the car just forward of the tank by the pick up in the tank.
  Randy

[pbf777]

I notice two different plumbing arrangements in the examples. Bob's photo shows the pumps plumbed in series (outflow from pump #1 goes to inflow for pump #2) while the fittings for the other photo looks like it's set up for parallel plumbing (inflow from tank is split going to both pumps and outflow from both pumps comes together on it's way to the motor). Seems like both would work fine ..........................

      Well, I feel the "proper" installation for function is to have them in parallel, as each unit has independent access to the reservoir and is adding to the total sum of delivery; versus a series installation with the singular draw sum effecting from only the first unit, which is the weak side of the system, with the potential gain solely being the perhaps drop in discharge pressure of this first unit due to the attempted draw of the second, and increase of the inlet pressure of the second, which one would anticipate an overall increase in delivery, but not at all equivalent to the parallel installation.       

      Also, consider the effects in the event of failure of one unit?       

      And as being opinionated, I would comment that in the photo of the parallel installation plumbing, in that the choice of the "T"s as somewhat lacking, as particularly on the low-pressure side the combination of the fuel turning 90 degrees into the first pump, over the machined fittings' short-turn creating a shear and the separation of the volume to the second pump unit simultaneously may induce a pressure drop, thereby an increase in the potential of a cavitation event, this definitely effecting delivery performance negatively.  Now, this may be offset by utilizing plumbing of excessive dimension, but this just compounds in inefficiency of the design.       

      Scott.

[mlplunkett]

Cobra Performance has the rubber top hat and the rebuild kit but no replacement wires or switches.
https://www.csxparts.com/c-223-fuel-pump.aspx

[gt350hr]

  The nice thing about a SW 240 A is that if used in conjunction with a mechanical pump on the engine , fuel will flow through it if it is in the off position. Running them in series is more of an "endurance" thing , if one fails the other will still provide fuel especially without a mechanical pump up front. Volume was not critical on a road racer back "then".
   Randy

[pbf777]

  The nice thing about a SW 240 A is that if used in conjunction with a mechanical pump on the engine , fuel will flow through it if it is in the off position.
   Randy

     Yes, we have successfully operated a sum of fuel delivery with the pumps in the "OFF" position just drafting fuel thru them with the mechanical pump for around town, and turning them "ON" when driving more aggressively.  When using the manual switch versus a pressure switch, just don't forget!  Don't ask me how I know!       

     But I have never actually measured when plumbed in series, what the fuel deliver loss would be, as attempting to draft thru or blow thru a dead pump?  Just seems like a bad engineering to me!       

     Also, as alluded to previously, mounting of fluid pumps high in relation to the fluid level being accessed is of poor intention, for several reasons, but most importantly it's the fact that as I stated previously, the suction side of the system is the weakest, and most prone to ailment when good practice is not adhered to, and the idea of expecting the pump to be lifting the fluid out of the tank enroute to the pump is to be avoided as much as is possible.         

     Scott.

[rkm]

In a 427 Cobra you can tootle around town with the electric pump off and just run on the mechanical pump, but if you push it, the suction tears the diaphragm out of the electriic pump.

[gt350hr]

  rkm , never had that problem in 46 years of drag racing with a 240A , but street driving is different.

[shelbydoug]

In a 427 Cobra you can tootle around town with the electric pump off and just run on the mechanical pump, but if you push it, the suction tears the diaphragm out of the electriic pump.

Use a Holley. It has no diaphram AND you can hear the radio when it's running as opposed to what sounds like a diesel generator in the trunk with the SW.

It was said that the drivers in the factory race Cobras would shut the pumps off. The Webered engines would run with no pressure regulator. Just plumbed directly to the little distribution block from the mechanical pump.

I use a Holley in the trunk to prime the carbs at start up and leave it at 3 psi. The mechanical pumps are more then adequate even under race conditions. That is unless you are Randy and regularly do wheel stands launching the car and need to overcome the severe g-forces generated by that?

That picture of the R model with the dual pumps is one of the Essex wire cars. The pumps weren't run in tandum. One was a backup for the other incase one failed. You normally can shut both of them off even under race conditions as the factory drivers did back in the day with seemingly no ill effects.

[Bob Gaines]

Make no mistake the SW 240 A was pretty much state of the art more then 55 years ago but not that today in comparison to modern offerings. The SW 240 A is more for nostalgia then any advantage over its modern counterpart.

[gt350hr]

  +1 I am a nostalgia guy that pits "old" against "modern"  and if "modern" doesn't provide a lower ET , I use "old" My car actually ran the same when the 240A was taken out of the system altogether. Must be the Carter Nascar mechanical pump doing it's job. 122 mph at the end of the 1/4 and 8,000 rpm does require "some" fuel  to do. LOL
    Randy

[1109RWHP]

I used a carter pump on my T/A Boss clone. I have a 240A in the trunk but is a gutted dummy pump just there to make it look correct. I did not like how small the inlet and outlet fittings were so I used -8 fittings and just looped it inside the pump housing.

[Bob Gaines]

  +1 I am a nostalgia guy that pits "old" against "modern"  and if "modern" doesn't provide a lower ET , I use "old" My car actually ran the same when the 240A was taken out of the system altogether. Must be the Carter Nascar mechanical pump doing it's job. 122 mph at the end of the 1/4 and 8,000 rpm does require "some" fuel  to do. LOL
    Randy

Dang that is spinning it. You are da man!!!! 

[dmb496]

Regarding gasket kits...the Ebay seller is a very good source.  I understand he's temporarily out of kits, but will eventually resume sales of them.

I've bought 20+ sets from him during the past 5 years. Early on when I asked him if each of the gaskets in his kit were compatible with today's gas/ethanol blends, he checked and found several were not.  He then remedied the issue and for years his gasket set has and still contains ethanol compatible pieces.  His kit includes a new black power wire.

I don't use vintage NOS gaskets for the reason stated above. 

[mlplunkett]

What Ebay seller are you referring to?

BTW on the series vs parallel pump plumbing debate I came across this photo on a GT40 site.