The fuel phantom

[SScopelli]

No..

I posted in your original post.. this...
https://forum.studebakerdriversclub....e-fuel-phantom

It sounds like your mechanical pump is having a hard time drawing fuel through the electric pump.

I believe Brad's advise is going unnoticed. Mechanical fuel pumps can only draw fuel from a tank if the line is clear. I do not think any mechanical pump was designed to suck fuel through a restrictive electric pump.

Here is one "prpoper way" to combine the two pumps.



In this case the mechanical pump draw fuel in the normal path, unrestricted..

If the electric pump is active, the check valve will prevent back flow to the tank and force the fuel to the mechanical pump.

If you have the electric pump in-line, i.e., where the check valve is, You may have created the phantom..


On the right is the R1/2 fuel pump. I am guessing you have the much smaller fuel pump the GH had.
The diaphragm on the R pumps were bigger than the standard GH fuel pump.



Even the original R fuel pump has only one small input valve, and one small output valve.

The performance pumps uses two input valves and one output valve to help suck the fuel harder from the tank.

[ATTACH=CONFIG]82527[/ATTACH]

[ATTACH=CONFIG]82526[/ATTACH]

[keithwahl]

Brad, thank you. Are you saying I should be using the larger mechanical pumo or cure the problem with the check valve? I spoke to the original owner and he put on 3 mechanical pumps, they all failed.. He went to electric only.. I am not sure if he plumbed through the mechanical pump
Can I keep my current pump and add the check valve?
Do you have the larger pumps.. Please email , text or call////kwahl@san.rr.com, 858 5182190...keith

[keithwahl]

How do you explain shut down with no fuel using mechanical pump going up a hill?? Other than perhaps disconnected pick up tube?

[bezhawk]

Here is one source of a check valve. Golden Hawks also have the fuel outlet in the top of the sending unit, not the bottom of the tank. There is a possibility of it sucking air under the right (wrong) conditions. You usually cant run a larger mechanical fuel pump without modifying the engine frame mount as the larger pump will hit the engine mount.
R2 Hawks had the mount heated and reshaped with a couple of good hits with a sledge hammer from the factory. Golden Hawks had smaller pumps. The diagram at the top of this thread shows a switch that only energizes the electric pump when the McCulloch blower solenoid is energized in high boost mode. In this case the switch would be activated any time the vacuum gets low enough to trip the switch. It would shut off under boost so it's kinda useless.

https://www.summitracing.com/parts/r...+5ba262b9d0879

[keithwahl]

Here is one source of a check valve. Golden Hawks also have the fuel outlet in the top of the sending unit, not the bottom of the tank. There is a possibility of it sucking air under the right (wrong) conditions. You usually cant run a larger mechanical fuel pump without modifying the engine frame mount as the larger pump will hit the engine mount.
R2 Hawks had the mount heated and reshaped with a couple of good hits with a sledge hammer from the factory. Golden Hawks had smaller pumps. The diagram at the top of this thread shows a switch that only energizes the electric pump when the McCulloch blower solenoid is energized in high boost mode. In this case the switch would be activated any time the vacuum gets low enough to trip the switch. It would shut off under boost so it's kinda useless.

https://www.summitracing.com/parts/r...+5ba262b9d0879

Brad...my fuel outlet is on the bottom of the tank!

[keithwahl]

BRAD - REVIEW ON CHECK VALVE WAS NOT GOOD - SEE BELOW - OTHER SUGGESTIONS?


It leaks
Summit RacingSummit Racing Verified Purchase

RNB-800-195
I used the hose barbs. I wrapped the threads with Teflon tape and attached the hose barbs and they still leaked. I took the off the hose barbs, cleaned off all the Teflon tape and applied some locktight - no more leaking. I also had to apply locktight to the two fittings that were pre-installed on the check valve.
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Reviewer: DANIEL from KS

Date: July 25, 2016

Appearance Ease of Installation Price/Value Quality
dorman fuel line check valve 800-195
RNB-800-195
waste of money does not work will not let enough gas to carb to run motor
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Reviewer: floyd from LA

Date: August 24, 2015

Appearance Ease of Installation Price/Value Quality
Don't bother
Summit RacingSummit Racing Verified Purchase

RNB-800-195
Don't bother. The barbed connector is attached using compression fittings. Both the supplied brass and plastic fittings leaked. The stock fuel pump will not pull an adequate flow thru this check valve to be useful.
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[tim333]

I’ll never understand why people put electric fuel pumps on to mask a problem instead of fixing it. The cars were designed to run on regular pumps so why not leave it that way??? I’ve never had any starting, vapor lock or performance problems in over 40 years of antiquing after properly servicing the fuel system.

[gordr]

Keith, we still haven't heard from you as to what kind of electric fuel pump is fitted to your car. The "impulse" types are basically a check valve inside a small piston that shuttles back and forth inside a solenoid. A mechanical pump can suck through one of those, but if the electric pump is too small, it might present a restriction when fuel demands are high. There are also rotary pumps, vane or roller, and they can present a major restriction to the flow of fuel, if not energized. Holley electric pumps are rotary.

Determine what kind of electrical pump is fitted, and then get back to us.

For what it's worth, I'd recommend that you remove the mechanical pump, and install a blockoff plate in its place. Make sure you electric pump has sufficient pressure and capacity to feed the engine at wide open throttle and full supercharger boost, and install a boost-referenced fuel pressure regulator, so that pump pressure does not blow the float needle off its seat during periods of low fuel demand. Today's fuel is not the same as what was available when you car was made. Less dense, and lower octane, and has alcohol in it. You do not want your engine to run lean under boost. That's a good way to get holes in the pistons, or hammer out the rod bearings.

Another good reason for going all-electric on the pump is that today's fuel evaporates much more readily than did fuel in the 50's, and it's not at all uncommon for a carb to simply dry out after a day or two. With an electric pump, the carb bowl can be filled with fresh fuel once the key is turned on.

One further caveat: the electric pump, whether used as a stand-alone or as a supplement, should be powered through a relay that gets its control signal from an oil pressure switch, so that the fuel is shut off if the engine quits running. That is a necessary safety measure to ensure that, in the event of a major wreck, the electric pump does not continue to pump fuel into the site of a potential fire.

[bezhawk]

It is just one I pulled up. Do a google search for fuel line check valves, and pages come up from Amazon and Ebay. Take your pick.

[Roger L.]

I have been following this thread (threads?) since the first post, and it seems that everyone has good intentions, but everyone is missing the point. His problem is that with a mechanical pump the engine starves and dies going up approximately a 30 degree incline. When both he and the previous owner uses an electric fuel pump this does not occur. While all the suggestions are worthy to solve fuel starvation issues the suggestions would be valid for level running or even down hill running, none of them really address his problem of starvation only when going up hill. I have no experience with supercharged engines so I can't address that but he didn't say if the starvation on hills occurs dependent upon the supercharger boosting or not. I'm assuming that it can occur at any time whether the supercharger is providing boost or not. I do have experience with the various fuel pumps though and that is what I'll address. After fighting with several Fairfield fuel pumps on my GT Hawk I finally gave up and bought a Carter from a Stude vendor, most problems solved, but still had issues with fuel delivery with alcohol based fuel when hot. I installed a cheap pulse electric pump from Auto Zone and installed it on the frame at the top of the rear axle arch. I have a filter between it and the fuel tank. I removed all the other filters. Except under extreme heating conditions such as when the engine gets up to around 200 degrees the mechanical pump has no problem pulling fuel through the de activated electric pump at any speed. As for electric motor pumps, I installed a Carter motorized pump that I got from NAPA on my 1942 M16. One thing that I did was check to see how much resistance it placed in the fuel line when not running by blowing through it, turns out that there is essentially no resistance to fuel flow because it is a vane type pump and when the motor is not running there is no restriction to flow through it, the mechanical pump also has no difficulty pulling fuel through it. Only problem is once the engine warms up the mechanical pump vapor locks and I'm forced to use the electric whenever I drive it on the road. Around town and running in the shop I never use the electric pump. I don't have a fuel pressure gauge on it, nor do I run a return to the tank on either vehicle. I realize that this does not answer the reason for the problem, but I see no reason to suspect fuel lines or the electric pump. If it doesn't starve when running on the mechanical pump when running on the level there is absolutely no valid reason that it should starve when going up a hill. The only thing that I could think of is a nearly totally clogged fuel filter that will supply enough fuel to operate on the level but cannot meet the slightly increased demand when pulling up a hill. One thing I might suggest is that you check very carefully if there may be a ceramic filter hiding somewhere in the line, typically screwed directly into the inlet of the carburetor. Fords use these and I've seen them supplied with some electric pumps. They are a tiny filter, maybe an inch and a half long and 3/4" in diameter. These things have no capacity and plug up quite readily. They can also be found behind the fuel inlet fitting on some Rochester carburetors. Beyond that I have no real suggestion for your problem. I do agree though with several posts that if nothing else works and there are no issues with filter restrictions then the best idea is simply to block off the mechanical pump and go back to the electric full time. Good luck trying to resolve this, I have a feeling that it may be something that just can't be logically figured out.

Roger List

[bensherb]

I’ll never understand why people put electric fuel pumps on to mask a problem instead of fixing it. The cars were designed to run on regular pumps so why not leave it that way??? I’ve never had any starting, vapor lock or performance problems in over 40 years of antiquing after properly servicing the fuel system.

Evidently you get better fuel in Illinois than we get in California. The fuel we get is NOT designed to function in a carburetor or mechanical fuel pump.

[bezhawk]

Evidently you get better fuel in Illinois than we get in California. The fuel we get is NOT designed to function in a carburetor or mechanical fuel pump.

EXACTLY! No fuel today is the same formulation as when the cars were designed. The fuel today is designed to be pressurized. Open atmosphere pressure and heat on todays fuel will in most instances give problems.

[keithwahl]

Fuel phantom 3 - 'unmasked"!!!!

THANK YOU EVERYONE WHO RESPONDED TO MY QUERRY! THE FORUM IS A GREAT PLACE FOR MIND MELDING!
Here is what we found and some of the respondents were right on the money.
The fuel line was crushed in 2 places
The electric pump - MR. GASKET - worked well for a long time. You could not suck through the pump
It was mounted above the gas tank. We re-plumbed the entire system
Manual pump with new steel line straight to the tank
We purchased a new small electric pump mounted close to the carburetor in parallel with the system using brass T fittings
The fuel filter is up high just before the carburetor inlet.
The solenoid on the supercharger is working and the belt tightens down at higher RPM just like it is supposed to.

BUT - I HAVE ANOTHER ISSUE WHICH I WILL POST SEPARATELY - PICK UP TUBE

THANKS AGAIN

KEITH

[showbizkid]

Keith, please keep it all in one thread for the benefit of future searchers. Thanks.