Cool Fuel

[Tomtall]

Had to ask this ? to BRF members to get your thoughts.

In the old days when I drag raced cars I would use a "cool can" to run my gas thru on its way to the carbs.( A coffee can sized container with alum. tubing coiled inside of it with ice and water added). I tried this same application years latter on our tunnel hull but we experienced a bog off the starting dock, so we did away with that idea. Now I am wondering if any one else has played around with this add on fuel system item with outboards and had any kind of positive results. :rolleyes:

[Roy Hodges]

in the old opc "R " class -unlimited up to 70 cu.inches, Mike schnell tried to keep his gas cold before & between the heats. He said the "light ends " evaporate first. He was running a merc800 (4cyl) on a SUPER Speedmaster lower unit (yes he was ) on a Ron Jones HYDRO(cab over) .He claimed he was the only guy who ever figured out how to run a big unit like that on a 12' hydro. He did not drive it, though. Terry Clemm drove it. it held the R kilo , i think @
107 mph.

[Mark75H]

I have seriously considered using a cool can in FE ... but I am guessing that the fuel lines and fuel pump would need to be insulated to be effecitve. You would also have to keep your gas on ice in a cooler pre-race and have an insulated fuel tank.

It might simplify things to use an electric fuel pump and return unused gas to the tank (similar to an overflow carb set up). If I do that, I'll add a second kill switch for the fuel pump.

[Roy Hodges]

Sounds good to me , ESPECIALLY on a HOT day.

Next idea; how about a long chilled air tunnel through the boat -to the carbs - to supply chilled
air to the induction "SYSTEM" ?

I just thought of that

( simpler to SAY , than to do , I admit )

[David Weaver]

When I was a kid, I remember some Alky teams doing this. I believe that Dick O'Dea's team tried putting methanol on ice before the races.

[Tomtall]

When we did this on our drag cars the cool can was maybe 3' from the carbs at most and our fuel lines had insulation wrap covering them. Our main reason for doing this was to keep purculation (boiling of the fuel) to a minimum in the float bowls. We were racing at 5000 ft. (1 mile high) and in 90 to 100 deg. temp. We pushed the gas from the fuel cell end to keep the fuel under pressure. Fuel is harder to boil (purculate) when under pressure then trying to suck it to the engine compartment under a vacume state from the tank. My consern with the outboards is that the fuel being used per minute is a lot less then a 800 h.p. big block. Which is going to allow the fuel in the lines more time to re-heat after it leaves the can. We also used alchohol on the ice as well, boy that stuff got super cold but melted the ice a lot quicker. Our cool cans were insulated with cork to hold the cold in.

[Mark75H]

My consern with the outboards is that the fuel being used per minute is a lot less then a 800 h.p. big block. Which is going to allow the fuel in the lines more time to re-heat after it leaves the can.

My thoughts exactly. With a recirculation system the carbs would always have cool being delivered to them.

The theory behind the cool can idea is that the fuel cools the air in the area behind the fuel discharge nozzle in the carb at least back to the reeds and possibly into the crankcase ... possibly enough to cause this air to shrink enough to cause even more air to pass thru the carb. Like a correctly working tuned exhaust, you can tell if it is working when it causes a mixture strength change (requiring a carb jet change).

[Master Oil Racing Team]

Try using just a little water as a starter and whatever voids there are between the ice, fill them with salt. Sodium chloride and potassium chloride are both endothermic and give off cold as they dissolve. That's what gives ice its boost in an ice cream maker. If I remember right potassium chloride (salt lite) gets colder quicker. Also, ice that's been in the cooler all night is not near as cold as ice fresh from the freezer. It's like fuel with the light ends evaporated off.

[Mark75H]

I've also considered using dry ice (solid carbon dioxide) as a booster, since it is a little below -100 F when solid at sea level pressure

I have also considered the possbility of dropping dry ice directly into the gas to pre chill it ... as long as I vented the CO2 vapor off. Does anyone now how soluable CO2 is in gasoline? It might make it fizzy and dilute it compounding vapor lock that Tom was avoiding

Probably would be too fizzy to use directly in gasoline ... I found it is soluable directly in both ethanol and acetone

[John Schubert T*A*R*T]

When I was a kid, I remember some Alky teams doing this. I believe that Dick O'Dea's team tried putting methanol on ice before the races.
David,

WE actually used a drag racer type fuel cooler. When I set the "C & D" competition records in Lakeland in 1969 that's what we used. It used to drive Dick nuts trying to locate Dry Ice for the cooler. The fuel was not pre-cooled and when you finished a heat, the cooler had to be re-filled with Dry Ice. At Depue that year, I won "C" & was 4th in "D", but we couldn't find any dry ice. We just used regular ice, which probably had little effect.

[David Weaver]

David,

WE actually used a drag racer type fuel cooler. When I set the "C & D" competition records in Lakeland in 1969 that's what we used. It used to drive Dick nuts trying to locate Dry Ice for the cooler. The fuel was not pre-cooled and when you finished a heat, the cooler had to be re-filled with Dry Ice. At Depue that year, I won "C" & was 4th in "D", but we couldn't find any dry ice. We just used regular ice, which probably had little effect.

Interesting. I specifically remember someone using it at Winona, MN one year at the Nationals (maybe with a Crescent 500cc ?).

[John Schubert T*A*R*T]

Interesting. I specifically remember someone using it at Winona, MN one year at the Nationals (maybe with a Crescent 500cc ?).
Could have been Dick with Jeff Hutchins driving but by then he had all but abandoned the Alky Crescent.

[David Mason]

If it is above 100 at the long course Nats in OK, we may need ice in our Kevlars !!!! Anyone have any ideas on that !!!

[Jimboat]

OMC factory tried cool cans in U-class boats in 70's on V4's. They used dry ice in an aluminum can, with fuel running through a coil inside the can. i don't really recall any of the other details, and it was hard to tell if there was really any positive improvements.

[Skoontz]

If you run a cool can on an outboard, it needs to be mounted at the fuel pick up on front of the engine to gain the most. You can easily make a plug in style connection on both ends and run the fuel through. Add this, a dry ice chamber around a 1.5' long velocity tube , just a pipe around a another aluminum pipe with an uncorkable end, and an oxygen injector either at the manifold/carb base, or directly into the velocity stack. We gained 300 RPM from the cool can, another 150 with the velocity stack, and nearly 1000 from the oxygen on a 50 HP Evinrude twin on a 13' Checkmate painted plum ugly.

It gave us a bunch for not alot of money because everything was hand built.

We actualy thought about cheese punching 1/16" holes every inch along the running surface of the bottom and adding a compressed air tank acting like an air hockey table. We never got around to pulling that feat off. I got the idea from John Wayne Janacky after he made his 105 MPH run with a box stock 235 OMC on his Switzer Shooting Star. He thought of it but no one ever implemented it.....Imagine the possibilities:):):)

[Tomtall]

What liquid can you pour in with the dry ice to get good contact with the tubing in the cool can?

David - I don't see why you couldn't use just plain old H2O. I know we do this every holloween to make the steaming witch's brew. I would think you would just need a small vent on the top of the cool can to vent the gasses coming off of it. Just an idea.

[mac19f]

It is common when using dry ice in a cool can to use isopropyl alcohol as the liquid.

[Mark75H]

Isopropyl alcohol is a very good idea, but remember 90% isopropyl is 10% water, don't be surprised to find a little bit of water ice in the container now and then, it would be a normal event.

The freeze/melt point for 100% isopropyl is -90 degrees C. Dry ice sublimes from solid to liquid at -109 or -104 F, but I don't remember which without looking it up.

[mac19f]

Water and alcohol together make a solution not a mixture. The water in isopropyl being the lesser amount is the solute and the alcohol is the solvent. So the water will not freeze separately from the alcohol. No more than the water in your car radiator would freeze out of the antifreeze because they are a solution not a mixture. It is also good to note that almost without exception, solutions freeze at a lower temperature than either of the two components separately.