Anyone tried this? Post shut down cooling.

Old Henry

Old Henry

Well-known member
I'm still trying to solve the gasoline smell after I shut down my 47 with 59A engine. In my garage I can just open the hood and it reduces the engine compartment temperature enough that the gas doesn't boil in the carburetor. But, when I park outside in the sun for a few minutes I can soon smell the gas. Pretty annoying. I know, I could open my hood every time I park but that's pretty ugly and annoying too.

So, I thought of this idea and wonder if anyone's tried it and/or what anyone thinks of it:

I would put the smallest 6 volt electric pusher fan in front of my radiator that does nothing until I turn the engine off. Since my ignition current goes through a kill switch relay with a normally closed contact I could hook the fan up to that contact to only be energized when I shut the switch off. Then I could control the fan by an adjustable thermostat switch with sensor in the air near the carburetor (discreetly, of course) so that the fan will shut itself off when the engine compartment temperature drops below 180 - the boiling temperature of some ethanol gasolines. Although it may seem that the fan would only be heating up the engine compartment by blowing air through the hot radiator, without the engine and water pumps running I'm thinking that the fan would soon cool the water in the radiator then be blowing cooler air into the engine compartment to cool the carburetor. The spoiler to that would be if the water started circulating through the engine by thermal syphoning. If that happened the fan would have to cool the whole engine before cooling the engine compartment rather than just cooling the water sitting in the radiator then cooling the air around the engine, particularly above it.

I know the un-energized fan in front of the radiator may drag and reduce some air flow. I also know there will be a drain on the battery for whatever period of time it takes to cool the engine compartment down and shut off the fan. Since I don't know how long that will take I don't know how much it might drain the 6 volt battery before the fan shuts off.

So, I'm wondering if anyone has tried anything like this and/or what anyone thinks of the idea. As annoying as hearing the fan running after the engine is shut off may be, I don't see it as annoying as opening the hood every time I park the car.

Thoughts?

P.S. Have Shewman's phenolic spacer under the carb that does no good at all and rightly so. The heat that's boiling my gas in the carb after shut down isn't just coming from the intake manifold, it's coming from the air around it under the hood.
 
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Henry, your normally closed switch with thermostat sounds like a stroke of genius! ...However, why not run it direct without that switch? Once the temp is under control, it won't come on anyway. This hookup will also help in slow traffic and at stop signs.

Like you, though, I wonder how much the battery will tolerate and still have enough juice to start the engine. I would think that a thermostat set for air temperature would cycle, so that may also be a factor to consider.

Sorry to be a wet blanket, I really do hope it works!
 
Might have merit, but think pushing/exhausting the heat out may work better.

Or, you could try a heat shield or phenolic <sp> spacer under the carb.
 
Mike B said:
Might have merit, but think pushing/exhausting the heat out may work better.

Or, you could try a heat shield or phenolic <sp> spacer under the carb.
Click to expand...

I was thinking the same. Pushing or pulling the heat from the Engine bay through the radiator out to the outside would be better.

In other words the opposite of normal radiator air flow.

This of course assumes the idea will work in the first place. If it does, it might work better one way round than the other.

Mart.
 
What about a Electric inline check valve on its own switch / Power on would shut Gas off keep car running a few moments. It may lower gas level low enough to not boil over.
The use of a spring loaded to neutral switch would give you the ability to hold the switch what ever time is needed to lower the gas level & cool down the engine @ the same time.
This brings up another point Does anyone let there engine idle after there ride to let it cool off ??
 
Henry, What year is your car, or more specifically, Where is the float chamber vent on your carb?
Is it at the front of the carb? Is it at the rear of the carb? Or is it internally vented, in the air horn?
If you don't have the internal vented one, then that would help because the fuel vapor may stay inside the air cleaner.

A fan running after you stop the engine in your garage, may just spread the vapor around more

What about fitting an electric fuel solenoid (separate switch) between the pump and the carb, and turn of the fuel before you get home (use up some of whats in the float chamber)
Just a couple of thoughts.
 
Professor,
What is the air temperature in your engine bay with the hood closed? Since this gas smell problem has not been supported by others who have a similar problem. I suspect you may have a gas leak in the under hood fuel supply lines/pump.
You feel pretty strong that an insulator between the carb and manifold is a waste of time. Have you used a laser gun to check temp with and without an insulator? This should be done before you condemn Bob Shewman's phenolic insulator.
John
 
Bluebell said:
Henry, What year is your car, or more specifically, Where is the float chamber vent on your carb?
Is it at the front of the carb? Is it at the rear of the carb? Or is it internally vented, in the air horn?
If you don't have the internal vented one, then that would help because the fuel vapor may stay inside the air cleaner.

A fan running after you stop the engine in your garage, may just spread the vapor around more

What about fitting an electric fuel solenoid (separate switch) between the pump and the carb, and turn of the fuel before you get home (use up some of whats in the float chamber)
Just a couple of thoughts.
Click to expand...



HEY / HEY I Just said that & NO!!! I will not share ( O wait I posted on the Barn ) O well no one reads this stuff any how. LOL :D LOL
 
My old Chevy stinks of gas when I pull it into the (attached) garage after a ride. I should probably park it outside, let it cool off and then pull it into the garage with the engine cold.

Or, how about a valve to shut off gas to the carburetor so you could drain the carb before shutting off the ignition. If the carb was dry, there wouldn't be any gas to boil off.

Also, years ago we had an old Subaru that had solenoid actuated flappers over the carb bowl vents to prevent vapors from leaving the carb.
 
What about fitting an electric fuel solenoid (separate switch) between the pump and the carb, and turn of the fuel before you get home (use up some of whats in the float chamber)
Just a couple of thoughts. I think Bill has the ultimate answer. If there is no fuel there will be no fuel smell.
 
Well Bill it looks like I'm not the only one who's not paying attention.
I think Your idea to fit a fuel solenoid is a great idea!:D (you'd expect that wouldn't you?)
 
oldford2 said:
Professor,
You feel pretty strong that an insulator between the carb and manifold is a waste of time. Have you used a laser gun to check temp with and without an insulator? This should be done before you condemn Bob Shewman's phenolic insulator.
John
Click to expand...

Another similar thought......
Maybe a set of Skip Haney high flow water pumps may have kept the engine temperatures low enough to prevent the gas from boiling when the engine is shut down..
 
Bluebell, Ford Barn is like a 2nd home, So what should I expect / NOBODYlistens to me at the 1st Home. Oboyyyyyyyyyyyyyyy

{ Come to think of it I have had people tell me I BELONG in a home } LOL LOL
 
ford38v8 said:
Henry, your normally closed switch with thermostat sounds like a stroke of genius! ...However, why not run it direct without that switch? Once the temp is under control, it won't come on anyway. This hookup will also help in slow traffic and at stop signs.
Click to expand...

I don't really want the fan running while driving. My generator has a hard enough time just keeping up with the headlights and radio.
 
BILL WZOREK said:
What about a Electric inline check valve on its own switch / Power on would shut Gas off keep car running a few moments. It may lower gas level low enough to not boil over.
Click to expand...

Bluebell said:
What about fitting an electric fuel solenoid (separate switch) between the pump and the carb, and turn of the fuel before you get home (use up some of whats in the float chamber)
Just a couple of thoughts.
Click to expand...

PeteVS said:
Or, how about a valve to shut off gas to the carburetor so you could drain the carb before shutting off the ignition. If the carb was dry, there wouldn't be any gas to boil off.
Click to expand...

Marv said:
What about fitting an electric fuel solenoid (separate switch) between the pump and the carb, and turn of the fuel before you get home (use up some of whats in the float chamber)
Just a couple of thoughts. I think Bill has the ultimate answer. If there is no fuel there will be no fuel smell.
Click to expand...

I have an easy solution for pulling into the garage for the night - open the hood. That situation isn't the problem.

Last Saturday I took the old folks to an art festival in the historic town of Spring City. We would drive a short distance between art studios/galleries then park and get out to see what was there. When we'd get back to the car people would be gathered around looking and asking questions. That's when the gas smell arrived and was a bit embarrassing. Same thing happens at national parks when we stop to take a look at something. That's the situation I'm addressing. Running the gas out of the carburetor at every one of those stops wouldn't seem to be the answer. I'd have to leave the engine idling unattended while we went into the place until the fuel ran out of the carburetor. Then fill the carburetor with the electric back up fuel pump when I came out to start the engine then repeat at the next stop.
 
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Bluebell said:
Henry, What year is your car, or more specifically, Where is the float chamber vent on your carb?
Is it at the front of the carb? Is it at the rear of the carb? Or is it internally vented, in the air horn?
If you don't have the internal vented one, then that would help because the fuel vapor may stay inside the air cleaner.
Click to expand...

Car is a 47 with 59A engine and Holley 94/Ford 59 carb.

Image1_zps2ab6c62a.gif


Bowl is vented internally into the top of the throat. When the engine is shut off the fumes come from there and gas boiling into the throat through the main nozzle.
 
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Cecil/WV said:
Why not just raise the hood since you know that works and quit guessing about other fixes??
Click to expand...

Raising the hood is an easy fix in the garage but not so good for the circumstances I found myself in last Saturday when I took the old folks to an art festival in the historic town of Spring City. We would drive a short distance between art studios/galleries then park and get out to see what was there. When we'd get back to the car people would be gathered around looking and asking questions. That's when the gas smell arrived and was a bit embarrassing. Same thing happens at national parks when we stop to take a look at something. That's the situation I'm addressing. Raising the hood by the side of the road at every one of those stops would not be ideal.
 
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