Just one more observation. I hooked up a small boat motor tank and piped it directly to the mechanical pump. Ran fine and no problem with stumbling or dying. Next I disconnected the electric pump and reconnected the original gas line from the tank to the mechanical pump. Again it ran fine, no stumbling or dying. I'm convinced that the problem is that the mechanical can't pull enough gas through the electric.

If anyone can suggest a way to keep the benefit of a priming pump without the problem of not enough flow when the electric is shut off I'd be forever grateful.

Thanks,
Ed

Ed,

You tested the flow of the mechanical pump...but not the flow of the electric pump. More testing is in order.
How about flow rate of just the electric? Then the flow rate of the mechanical pulling through the electric?
A stop watch and graduated container would give you a decent idea.

It is possible that your electric pump is not a true "flow through" pump. Many pumps are advertised as having a certain "free flow" rate, but that is not the same as flow through.
It could also be that your pump is damaged/not working properly.
I, and many others have been running flow through pumps along with mechanical pumps with no issue for years.

Currently, I'm running a flow through from Napa
http://www.napaonline.com/Catalog/CatalogItemDetail.aspx/Fuel-Pump-Solid-State-Cube-Type-/_/R-BK_6101051_0498208121

The car runs into the mid 90mph range, will pull a heavy trailer, and can climb pretty good hills with no bogging down or fuel starvation, on the mechanical pump which is pulling through the electric, which is in place as a priming pump.

Rob

Sam-

I'm glad you got the problem solved! I'm like Doug, though, how did they ALL get loose? They do tend to loosen up over time and I usually make it a habit to check them whenever I'm doing a tune-up.

As far as the electric pump in line with the Mechanical pump goes, I wanted to mention that I had been running Carter Flow-through pumps (in conjunction with the Mech. pump) for about a hundred years until just recently. Again, and like the points, condensers, etc., these pumps are no longer made here but elsewhere and quality control has gone bye-bye. Apparently about 1 in 10 is the going rate for finding a good one (or so I have been told). My sedan has been running one for over 10 years with no problems, but the one I put on the convertible was a no-go, as was the one I replaced it with. Upon recommendation by Wildrick, I went with, believe it or not, a Mr. Gasket Flow-through pump (which are still made in USA) and so far, so good. Before the switch, I was experiencing the exact symptoms. I knew it was gas starvation because I like to utilize glass, or see-through fuel filters because it gives you a visual about what is going on as far as fuel flow. No more 1/2-filled filters. They're full up and ready to GO! These days you can't take it for granted that the part off of the shelf is worth a damn.

I've never messed with them, the car was sitting otherwise, so maybe just with time or some where down line they slowly loosened, all I know is it runs perfectly now , even hooked back up the mechanical fuel pump

Sam,

Glad you got your car back! Now you can enjoy it 😉

I chased a minor miss for years on another car (non Hudson) tried everything I could think of. In the end it turned out to be a bad valve. That engine never sounded so sweet after removing that annoying miss.
Most all of these old car problems can be traced back to deviations from the original state...the trick is figuring out which part changed.

Rob

About having the mechanical pump and an electric pump.

On a '41 Commodore 6, I had a 6 volt pump in parallel with the mechanical pump. I only used it to fill the float chamber. Since it was not in the way of the gas going through the mechanical pump, I didn't have a problem with fuel starvation.

On my '35 Hudson 8, I have two feeds to the carburetor. One is the regular gas tank and mechanical fuel pump. The other is a small container of gasoline and a fuel pump from an early (carbureted) Honda. There is a 12 volt battery to run the electric fuel pump. I use the electric pump to fill the float chamber.

Per

This Napa pump looks exactly like the 12v Mr.Gasket pump we buy from O'reilly autp parts. We have had great luck with them, and don't even bother with running a mechanical pump. Less places for heat transfer to the fuel system, the better-IMO

Doug,

Very likely the same factory makes a number of pumps which then have different badges applied. Or, they all copy each other...

A modern electric pump sure doesn't need a mechanical backup. Personal choice in my case. The car had a full time electric pump and a block off plate on the engine block. It worked fine, but the constant drone and vibration of the electric pump bothered me, so I replaced it with a flow through, and installed a mechanical pump.
Best of both for me! 🙂
(Some electric pumps are pretty quiet, and if you isolate them with extra rubber mounts the vibration isn't too bad)

Rob

this is true. We have been putting headers on most of our 12V conversions and the pump can't really be heard. We just completed our '42 Deluxe with a great running 262 !! It is alot of FUN !!
[quote="Rob Hesselmann " post=13820]Doug,

Very likely the same factory makes a number of pumps which then have different badges applied. Or, they all copy each other...

A modern electric pump sure doesn't need a mechanical backup. Personal choice in my case. The car had a full time electric pump and a block off plate on the engine block. It worked fine, but the constant drone and vibration of the electric pump bothered me, so I replaced it with a flow through, and installed a mechanical pump.
Best of both for me! 🙂
(Some electric pumps are pretty quiet, and if you isolate them with extra rubber mounts the vibration isn't too bad)

Rob

Currently, I'm running a flow through from Napa
www.napaonline.com/Catalog/CatalogItemDe...K_6101051_0498208121

Do they make a 6V pump also? I can't get any information on line from NAPA on either 12V or 6V.
Lee O'Dell

Lee,

Not sure if Napa carries 6 volt pumps, but Carter makes a 6 volt regular, and Airtex makes a 6 volt pass through.

Rob

I've isolated my electric pump with rubber mounts. If I'm sitting in the driver seat, door open, engine running, I have to walk around the other side of the car to hear it. Pretty quiet.

NAPA has the Facet Posi-Flo BK 6101051 electric 12V fuel pump at 10% discount until the 21st by reserving it on line. I picked one up today for my 47 PU $48.60 plus tax. I asked NAPA salesman if Facet makes a 6V positive ground pump. Answer is No.
Lee O'Dell