Logo
FULL SITE MENU

electrical fuel pump conversion

circle hook

circle hook

Regular Contributor
hello I can not locate a fuel pump for my '1971' 318, so it looks as if I have to convert to electric fuel pump. when in stalling one do I need to reroute a line back to the fuel tank I was told. if so how do you do that. and does anyone know what is the best type, make ,model, to buy. Carter M60980 is the mechanical pump I have now. Thanks Bob
 
Bob, if carbureted, you can use the low pressure (4 to 7 psi) electric fuel pump.

images


A gasoline return line is unnecessary and would be illegal.



You will need a N/O low oil pressure switch in the loop. This ensures that the pump will not continue to operate if the engine was to shut down.
Because of this, you'll also need to incorporate a "start by pass" circuit, so that the pump will operate prior to engine oil pressure coming up.

If you do the "start by pass" circuit (using the starter motor's solenoid circuit), you'll need a relay in the loop to prevent current back feed.

Or...... you could install a momentary helm switch that circumvents the N/O oil pressure switch just prior to start up.
This switch MUST be a momentary switch.
This is actually a great way to go, because you will be able to prime a carburetor (that may have evaporated fuel) without cranking the engine over.
This extends battery life, and saves wear/tear on the starter motor.
.
 
that pump you have in the picture do you have the part number of it. and all these switchs & relays do they com e in a kit or do I need to make it all up. Thanks Bob
 
circle hook said:
that pump you have in the picture do you have the part number of it. and all these switchs & relays do they com e in a kit or do I need to make it all up.
Click to expand...
Bob, the one shown is a Carter P4389 - Universal & Marine Electric Fuel Pump.
I'm not seeing one available in kit form with the N/O low oil pressure switch nor a relay.
The N/O low oil pressure switch is a USCG requirement. The "start-by-pass" circuit is optional in lieu of the momentary helm switch.
Quite honestly, I prefer the momentary helm switch over the "start-by-pass" circuit.

You should be able to find these parts at your Marine Parts Supplier.


Bob, I'm reluctantly posting a link to a video for an automotive installation to show the oil pressure switch install.
I was not able to find a good video showing a Marine installation ..... (too many unqualified DIY'rs out there!)

NOTES and Disclaimer:
This man is not installing the Carter style pump that you'll want to use.
You'll want to use SS band clamps at the fuel line connections, in lieu of the spring clamps. A1-15 fuel line is USCG approved.
You'll want screw-down terminals on the N/O low pressure switch (not the push-on style).
Use thread sealant in lieu teflon tape.
Be sure to use the correct style wire fittings and crimp tool for Marine use (he is not).


Just for fun, here's a knucklehead who did an installation whereby he now pressurizes his fuel filter canister. :eek: :rolleyes:
We DO NOT want to pressurize the carburetor style fuel filter canister!
This video should be removed from YouTube.... :mad: ... or at least "flagged"!

Bob, make dang sure that your fuel filter is installed prior to the electric fuel pump! We want to "Pull" through this filter... not pressurize it!
Had this guy done the installation correctly, he'd not need the small in-line automotive fuel filter shown. :eek:




.
 
I will ask at store we have west marine stores, they may know what I need you think, and the system well the old system the water separator / fuel filter is a raycore, and is before the old mechanical pump, but there is a small metal filter after the pump also should I remove that. that was on the engine like that when I bought it. Thanks Bob
 
Bob.... me in blue text.

circle hook said:
I will ask at store we have west marine stores, they may know what I need you think, and the system well the old system the water separator / fuel filter is a raycore,
RACOR is good stuff.
Check the aluminum bowl for corrosion, replace the cartridge, and you'll be OK.

FYI.... the plastic bowls are illegal for inboard gasoline installations.

and is before the old mechanical pump,
That is exactly where it should be.

but there is a small metal filter after the pump also should I remove that.
Yes, the square filtration area of these little filters is far too small to be of any use.
They have no place in a Marine installation.

Your RACOR will be just fine all by itself.
Click to expand...
 
thanks now need to figure out how and were to buy that low oil switch they are speaking about any ideas or part numbers. thank bob
 
no not having a problem finding a few pump number, but finding a carter fuel pump for a 1971 Chrysler 318 small block marine engine. its number M60980 and everyone is sold out at this time. so I am looking to go electric and to it right I need to wire it to a low oil pressure switch if the engine shuts down the pump will also shut down. I need to know where to get this part, and its part numbers. thanks bob
 
Do a Google search using Key Words; "normally open low oil pressure switch"!

My preference would be to allow the oil pressure switch to trigger a relay, and to let the relay handle the amp load of the electric fuel pump.


.
 
Last edited:
That's the way I did my conversion. Hard to find a convenient source of key-switched-ON 12 volts that isn't already being used for some other purpose. I took a 12 volt feed right off the battery cable, but I also installed the correct size in-line fuse for the pump.

Jeff
 
I fully agree with Jeff regarding the key switch "on" having enough loads on it as it is.
I'd not add more loads to this circuit!

This is why I prefer using a relay whose power is derived from an independent source.
With the keyswitch "on" circuit triggering the relay only, this load is rather insignificant.

I am a NAZI when it comes to direct battery connections!

Direct battery connections do the following:

begins or creates an unwanted direct battery connection "rat's nest".
adds to the confusion when removing and replacing batteries.
dedicates that circuit to the battery that it's connected to ONLY!
takes the MBSS out of the loop.

I'd suggest taking the relay power from somewhere within the engine harness system (fused of course).
Now the MBSS is back in the loop, and this power will be derived from the bank being selected at the time!




.
 
Last edited:
Go to summitracing.com
they can provide:
HOLLEY marine fuel pump
oil pressure switch
electrical harness, relay and wiring diagrams
not a big job at all and the install is USCG compliant.
Joe
 
Back
Top