Electric fuel pump in 8 volt system?

[riversidevw]

The fuel pump in my '55 Speedster has just quit. It appears to be a more relatively recent generic replacement. Because of the concerns (oil leaks, etc.) with a lot of the currently available new pumps, I've considered an electric unit, perhaps a Carter. Tony Wisniewski, from whom I bought the car last spring, had converted the Speedster to 8 volts. Not sure whether he did it because of starting issues or ?.

Any experience out there using a six volt pump with an eight volt system? I've actually given some thought to reverting to 6 volt setup prior to this.

Thanks.

Gil

[Roscomacaw]

Almost ALWAYS, this 8V redo is because of starting issues. Of course, you DO get a bit brighter lites out of it as well as faster heater, wipers, etc..

With PROPER-SIZED cables from the battery to ground and to the solenoid and solenoid-to-starter, it should start with ease.

8V to that pump? Figure it's going to last awhile - maybe years, given the relativley little use I presume the car will see, but like anything else on steroids, figure it's life to be shortened to some (maybe minor) degree.

1957 Transtar 1/2ton
1960 Larkvertible V8
1958 Provincial wagon
1953 Commander coupe
1957 President two door

[whacker]

I think it depends on the type of fuel pump you use. I have run a 12V pump on 6 volts with no problems for a couple of years. I recently converted to 12 volts in my 1951 Commander, and just kept the same pump. I think you will do fine with 8 volts if you get a 12 volt pump. Mount it back by the gas tank and use an oil pressure cut off switch (when you loose oil pressure, the pump stops).

[riversidevw]

There is a 6V Carter rotary vane unit which is apparently compatible with positive and negative ground sysems. I've haven't found any 6V version of their newer solenoid type pumps.

http://www.thehotrodcompany.com/shopnow/show_item.asp?product_id=P4259

StudebakerParts.com also lists a 6V pump, brand ubspecified.

https://www.studebakerparts.com/studebakerparts/store/s/agora.cgi?product=fuel3&cart_id=404.2224

Any experience with either?

[Flashback]

Ran a 6-volt ac pump for years with a 8-volt
battery for over 4 years

Tex E. Grier

[tim87114]

In general terms when you talk electric pumps IE motors, if the rating is 6vdc at a specified RPM then at 8vdc it will just spin faster. The same holds true to when an altinator kicks in on in a newer type car. When the engine is running at an idle if the voltage is above the voltage regulators required voltage a fuel pump would be turning at a speed rated between the 11 and 12vdc produced by the battery. Turning on the head lights would cause a drop at the battery inturn requiring the voltage regulator to send current from the altinator to the battery with a voltage output from 13.5 to 14.6 vdc appx. When this happens the fuel pump would incease RPM's due to more power available. The excess fuel from the higher pressure is sent back to the tank through the Fuel pressure regulator and bypass/return line.

In the case of an 8v system with a generator it works the same. A 6vdc rated pump installed on an 8vdc system would spin a 1/4 time faster as it is 2vdc. If you install a 12vdc rated pump it in theory would turn slower on your 8vdc system and last longer. But again, the speed at which it turns is completely dependant on how it was designed.
In otherwords installing a 12vdc fuel pump on your system would increase the pumps life span as it would turn slower and generate less heat. But you would have to be sure that the fuel pump pressure would hold acurate. Which it should considering the voltage difference isn't enough to worry about.

[riversidevw]

Many thanks for the information.

Local shop yesterday completed installation of a 6 volt pump (an AC. their choice). Car starts quickly, pump is inaudible. The oil-oozing, only intermittently functioning generic mechanical pump has been replaced by a blocking plate. Seems like a great choice. May be frowned upon for judging, at this stage of my life reliability is more important. I do try to limit visible mods to things that can be easily undone by a future owner, especially a car like the Speedster.

Incidentally, the OEM style mechanical pump in our '58 President has worked flawlessly for decades!

Gil and Maria

[Carl Purdy]

I know of one points getter cars that has a electric fuel pump. He took the arm off of the fuel pump and made a aluminum plate and gasket and bolted it on and run dummy lines. You can't tell it from the real thing. Just a thought.


7G-Q1 49 2R12 10G-F5 56B-D4 56B-F2
As soon as you find a product you like they will stop making it.

[Mike Van Veghten]

Agree with wacker -

I've been running a 12 volt Carter for a coupla years on 6 volts with no problem. Just have to remember to swap the polarity for the positive ground.

Mike

[RHO]

Have been running an 6-volt pump for priming and when vapor lock occurs on a '53 SuperWasp with 8-volt battery for nearly ten years.

'55 Commander
'55 President