The Stovebolt Site Forums The Shop Area Engine Shop Setup For Using Electric Fuel Pump

OK, '60 235 in my 3100 build. Under bed tank. Going to use a low pressure electric pump (wired to the ignition I think would be correct?).

If I lose the pump on the engine what do I do to block off the pump chamber so I don't lose vacuum?

If I lose the pump on the engine, do I run the fuel line straight to the carb?

Lastly, I had a line going from a vacuum can on the distributor to the carb, too. What is this?

Why do you need an electric fuel pump? Is that what you use for an under bed gas tank? It is NONE of my business, but it made me curious. Sounds like it would complicate things to me. That's just me & I'm learning too.

Whatever you end up going with, you can just make the mechanical fuel pump a "dummy" and leave it where it is and solve the 'block off the pump chamber' question. Take the guts out of it, reseal it, & put it back.

If you are going with an electric fuel pump, you can just run the fuel line from it to the carburetor. The mechanical one is out of the equation. Though I did read a post a few months ago (or saw an add?) about an electric/mechanical pump combination. I do remember the writer was pleased at having the mechanical pump as a backup.


The line from the vacuum advance on the distributor to the carb is called the vacuum advance line. It helps out ignition timing. Here's what the internet says about it because I can't explain it to you myself.

I hope this helps, and I'll be following this to find out about the electric pump.

Brad

Just run through the mechanical, use the electric to push fuel up to the mechanical pump. You will not need the electric pump just because you moved the tank, the mechanical pump will pull fuel easy enough. If you just want one, no big deal. If you use both and one fails, the other will keep you on the road, just be sure the mechanical can suck fuel through the electric. Most electric pumps will allow fuel to pass through. Always check fuel pressure at the carb once you have everything up and running. 2 - 3 psi is all you want, anymore and you can over power the floats.

For hooking one up, I would use a safety switch as GM did. Go to NAPA and order up a switch # OP6610 and connector EC428. Both are from a Chevrolet Vega. The switch is three prong oil pressure safety switch. It activates the fuel pump only when the engine sees oil pressure. If the engine dies, so does the pump. I have drawing I can e-mail you if interested, it shows how to wire pumps. ( I don't have a way to post it )
The third prong on the switch is for low oil pressure dash light if your truck has one. I also use this post for hooking up a primer button, so you can fill the fuel system before starting with a push button. It comes in handy if the truck sets for long periods.

Joe

From Cletis web site


http://jbhardin-gallery.com/trucks/fuelpump.html

Brad -

Several people told me they didn't think the stock pump would draw the gas well enough from the rear tank to the engine for a variety of reasons, all of which I agree with. So I'll use the stock pump and see but will likely need the electric.

The gas tanks in passenger cars with Stovebolts in them are farther to the rear than yours, and usually under the trunk and they use the same mechanical fuel pump that's on your engine with no problems. Sounds like those people you've been talking to are trying to create problems where there isn't any.

Just about every car built since the 1930's to the mid 1980's has the fuel tank in the rear and a mechanical fuel pump on the engine. Didn't seem to be a problem for 50 years. Everything I own, about 10 vehicles with carburetors including cars, trucks, and equipment, has both a regular fuel pump and an electric pump. Many set for long periods so the electric pump is turned on to feed fuel up to the carb instead of grinding on the starter a long time. As soon as it fires the electric pump is turned off and it runs on the mechanical pump.

This is entirely possible and I am a noob to the nth degree so I wouldn't know.

So how's the electric pump wired so it switches off after the engine is running?

electric pumps are 'on demand', maintaining a certain pressure - they may also be way too high a pressure for a stock bolt so requiring a pressure regulator, and they might not shut off in an accident

you don't need an electric pump JR, mechanical pumps are more dependable and work fine from any tank location, no need to make it more complicated

Bill

Electric fuel pumps that supply between 2.5-7.0 psi are available. The mount outside the fuel tank. And, no pressure regulator would be needed. Cletis's pump is 4-5.5 psi at 32gph.

Airtex makes a 6v (+/- ground) unit that is inexpensive enough that you could keep a spare in the glove box.

I am not recommending this, just giving information.

OK all I will run the stock mecho pump from the rear tank and see how it goes.

jrdamien- thanks for bringing up the topic; I learned several things I didn't know. Appreciate all the info & links fellas.

Brad

Likewise, as always!

Now, do you run a flexible fuel line from tank to hard line and from hard line to pump?

This is not a race car or truck, BUT, NHRA rules state, " no more the 12" total non-steel or braided fuel line front to back " . Thats a pretty good rule to follow no matter what you do with the truck. So, use minimum amount of rubber line to splice in the extra pump.

Joe

They also make a high performance mechanical pumps if you're worried about not enough pulling power. I run electric on my 65 c-10 and my 04 cummins.