[puttster]

To keep my gas cool I was thinking of installing a regulator at the carb and circulating the extra gas back to the tank. Then I realized that might keep the gas in the line cool, but not the gas in the float bowl.

My carburetor came with a spacer that has a nipple front and back for circulating hot water from the intake. I've disconnected the hoses to it but... I was wondering if, on its way back to the tank, the gas got circulated through the spacer, it would keep the float bowls cool?

 

[KULTULZ]

IMO-

I think you will be making one big fire hazed. Just use a phenolic spacer and heat shield.

BTW- The return feature you are thinking of does cool the fuel.

 

[FEandGoingBroke]

Thanks Kul, zaklee what I was going to say!

 

[puttster]

The open float bowls will have more gas in them than the spacer will. And folks use high pressure pumps with quart-sized accumulators in the engine bay all the time. Safety issues or Chicken Little issues?

 

[PSIG]

Safety issues or Chicken Little issues?

That depends on who did the work.

David

 

[puttster]

That depends on who did the work.

David

Fair point! What about the cooling question?

 

[FEandGoingBroke]

The cooling will definitely be happening with a recirculating fuel system.

The issue is in modifying your carburetor to be a flow through (without bubbles) system in which you have restrictions to allow the fuel level to be maintained while allowing new fuel to enter and exit allowing the cooling to happen.

THAT is where the safety issue is.

 

[EXracer4speed]

Any particular problem your having?

 

[puttster]

I was thinking about a design along these lines. Not sure if a mechanical pump will move enough fuel to be useful. And maybe I don't need a regulator, just a restriction of some kind.

 

[FEandGoingBroke]

That's not doing much to keep your fuel cool, it's simply dumping it into the fuel bowl where it sits and get's hot when the engine is shut off.

The fuel coming and going to the tank will be cool, but that's moot once it reaches the carb becasue once there is sits....

 

[ShotRod64]

I also wonder about the degradation of the aluminum from the ethanol injected fuel. Doesn't the fuels of today eat away at the aluminum? Although spacers are aluminum they aren't designed to retain fuel. But that could be a while before it actually degrades enough to cause a leak i suppose.

 

[puttster]

I see what you mean, FE. Once the engine stops, so will the gas flow in the spacer? After that it will start to warm up and transfer that heat to the carburetor.

To Ex's question, I am not having problems with evaporation gas now but lately I have seen several posts complaining about it and wanted to head off problems. I see though that the offending evaporation takes place after the engine shuts down. My design might help but might not.

 

[FEandGoingBroke]

In order for it to work the bowls need to be flow through. And they should have a fuel pump that keeps pushing fuel after the engine is shut off, like the electric fans that stay on after shutdown.

 

[PSIG]

My design might help but might not.

True, and you'll never know unless you try it. However, the primary source of shutdown heat soak is the very hot manifold. My two first steps would be a phenolic spacer and blocking the manifold heat crossovers. Unless you live in northern Minnesota or similar, blocking them extends warmup about a minute with no other ill effects. I always block my crossovers on performance vehicles (duh), but also on daily drivers that don't see much time below 0°F.

The up-side to your idea is that it's virtually bolt-on without pulling manifolds and such. Maybe try a test version that uses a little pump (windshield washer pump?) to just circulate water through a front-mount cooler and back. Perhaps it would allow enough heat sink to prevent the bowls from getting to boil temp. It would be a simple and cheap experiment to test theory without the dangerous aspects.

If it works effectively, showing the actual temp reduction from testing, I'd be one to use that, or possibly a fuel-cooled version. I have no issues running fuel all over the engine as I and the rest of the planet do now with EFI hoses, rails, regulators, etc. at much higher pressures. Go for it and post the results Mr. Guinea Pig. :tup:

David

PS: I can send you some tiny stick-on remote temp sensors to check bowl fuel temp and water temp during testing. Let me know. You just need an ohm meter to read them.

 

[puttster]

Running the fuel pump for five minutes after the engine cuts out is probably what needs to happen. I would of course combine that design with a promise to myself not to rear-end anyone...

The windshield washer pump suggestion got me thinking also. I have a 1 qt washer reservoir in the engine bay. If there was a switch that could divert and circulate that water through the spacer after the car was turned off, well that might do the job.

 

[BH107]

In my opinion all you are going to do is heat up the fuel, not cool the carb. A phenolic carb spacer is a start, and then build a heat shield to protect the carb from radiating heat from the top of the engine.

 

[Cruisin63]

How about running the fuel through a trans cooler with a fan Lol.

 

[ShotRod64]

and thermostatically controlled like electric fans so it continues to run til a certain temp is reached or specific time allotment.