Cold fuel

Was racing down in Kentucky at a Mopar event last October.
Kinda had a pretty good handle on the numbers the car was running in different conditions at a new track( to me)
Next morning checked my fuel cell, almost out of gas(110)
I had purchased 5 gallons the day before, went back to hotel after racing, left the can sitting outside, dipped down into the upper 30’s over night, like it had the night before.
I dumped the “ cold fuel” into my cell, went up and shortly made a hit…
Car out of nowhere picked up 4 in the 1/8th.
Scratched my head about that, where in the world did that come from?
Only thing i can think of is the literally nearly ice cold fuel was the culprit.
If that situation ever repeats itself…..

All you got was more fuel in the mix so test with more jet but the conditions may not replicate.

Thats a lot but yes, I'd bet its the cold fuel. Engine masters did an episode trying to see if icing the intake helped, I forget all of the details but what they found was that it helped but it was because it made the carb bowls cold and the fuel was actually cooling the air charge alot, not that the cold manifold was lowering the IAT. The actual temp of the manifold was almost completely insignificant, but the fuel temp was important.

Remember everyone used to run those moroso cool cans?

My buddy used to race drag bikes, they had small tanks (less than a gallon) He used to keep the fuel in a milk jug, in a cooler full of ice

Any on e ever hear of a "COOL CAN" it was a 1gal ish sized can under the hood that the fuel line ran through. just before each run you would pack it with Ice to cool the fuel during the run...

I have a friend that tried a Moroso cool can years ago. He said when he packed it with ice, it would make his fuel pressure drop from 7 to around 3 psi. It still ran fine, but that bothered him so he removed the cool can.

I have never used a cool can, but have any of you seen this? It makes sense since the fuel is cooler and denser. Do you reset the regulator so the pressure is back up to normal or what?
They're one of those old school hot rod parts nobody uses anymore.

The early ones were nothing more than a can wrapped with cork with a metal lid that that just rested on top. Later versions were better insulated and sealed.

didn't NHRA outlaw those because of water on the track issues ?

I think i actually ran a cool can on a car back in the 70’s it was kinda a thing most everybody did.
That said, the result i had that morning i think was way different than a cool can
I dumped gas in my cell that was probably 42-45 degrees and in short order was sucking that stuff into the motor.
You take a typical day, the fuel is never that cool, even a cool can( i doubt) will cool all the inbound fuel to that temp..although i could be wrong

Don, did the gas in the car and the can come from the same source? Was the carb tuned in hot weather?

Carb heat plates, Cool cans, wooden carb spacers etc......The Rossi Challenger run by the Hausers over here had a cool can, watched a guy@ Santa Pod running 10.10's pack the manifold with Ice before a run and went into the 9's.....cool it, it works, has done for yonks.

Speaking in a glittering generality here but the colder the fuel the quicker you will be...We make every effort possible to keep the fuel as cold as possible in the heads up car. In a bracket car its not very practical honestly.

Same stuff. I tune for shoulder weather, early and late summer. Leave it alone for spring and fall. Bracket car..moves around the least doing that seems like.

I can't hang a number on it as I don't have that kind of experience.

But I remember seeing a someone else's test a little while back, entire intake and carb was iced during a dyno test.
Temp guns on the manifold showed it heated back up to where it was almost instantly,
as did the air temperature, But the carb and the fuel did not.
It picked up and they pointed to cold fuel, given all else.

Seems to agree.

cool cans are legal in nhra stock, moroso makes a polyurethane 65125, cannot be mounted on firewall, plumbing my stocker for one
65125 was 3/8 npt now 65127 #8 AN

don't forget dry ice in the fuel cell.

I've seen many NHRA class racers ice the intake to gain a tiny advantage when they thought they needed it in a heads up class run offs at the Winternationals and the World Finals at Pomona more than once

At a NHRA divisional race a couple of years ago, my fuel check after a qualifying run was marginal. The tech guy asked me if I had put dry ice in the fuel cell. It happens.

When we were racing my Buick we had a cool can on it. One day I pulled into staging when it was about 100 out. My buddy Russell pops the hood open, and pulls a can of Pepsi out of the cool can. People freaked out.

Dry ice .....interesting who does this work?

put the dry ice in a sealed baggie??? might be hard to handle, liquid nitrogen for cooking???, might be able to do the same with regular ice, never thought of it

You cant put dry ice in a bag, well you could, but the dry ice will sublimate and blow the bag up. The carbon dioxide gas has to go somewhere.

does dry ice evaporate or turn into water?

It sublimates….turns directly from solid carbon dioxide into carbon dioxide gas, it’s CO2….not H2O

I thought bout this with regular ice but how would you control the condensation from ice melt contaminating the fuel?

Huh? A cool can is like a chemistry or distillation still, coiled fuel line within a can that allows water or dry ice to cool it, there is no mixing of fuel with anything.

I ran one on the street back in the early 80’s. A Moroso, the fuel line is coiled around the circumference of the can. Regular ice melts way too fast. Dry ice is what you want. Walmart sells dry ice.

Years ago, i remember see a guy that used a half gallon water jug as a fuel cooler. It was setup like the cool can that Moros use it was click.

Engine masters did a dyno test on cold intakes, cold fuel & it picked up power with very cold fuel

I have to ask a question here.

The colder a liquid is, the more heat it takes to evaporate it. Liquid fuel doesn't burn, only vaporized fuel burns.

If you send cold fuel to the carb, it seems to me you would have to run a richer mixture just to get the same amount of vaporized fuel, to burn.
What happened to the rest of the liquid, unburned fuel ?

This is a different argument from having colder intake AIR, which is already vaporized.

If the cold fuel particles don't or can't absorb enough heat in the few milliseconds it takes to travel from the carb discharge tube to the cylinder,
it won't burn. And it doesn't necessarily all evaporate in the intake stroke, or even in the compression stroke.

I have heard of bracket racers going through a gallon and a half of fuel in one run. There is no way all that fuel is burning.

What type of fuel?

Quarter mile, I used a gallon a run. C12. That includes warming it up in the morning, driving it to the lanes and back, plus the run. Obviously less than a gallon to go A to B. Based on memory, maybe 3/4 of a gallon from the trailer, to the lanes, down the track and back to the trailer. Maybe.

Granted, I wasn't moving a huge amount of air, making big power or using a big carb,

i use to count on around a 1/2 gallon per 1/4-mile run bracket racing in SO CA with both race gas and pump gas with the Duster.
My current E85 bracket car uses around 3 gallons to warm it up doing 3 laps in the morning in the pits and drive it back after 3 1/8 mile pass at Madras, OR
This car is hard to get heat and keep heat in the motor using E85 hence the extensive warming up each morning before racing it
All my other cars got hot a lot quicker on gasoline than this car does, even though it is making a lot more power than the gas motors did

That is the can i had.

In a race application, you don't want fuel vaporizing in the intake. The vaporized fuel displaces oxygen. You want just enough vaporization to start the combustion process.

Here is an article about carb boosters, but later goes on to explain cold intakes vs warm.

https://www.motortrend.com/how-to/0511phr-carburetor-boosters-tech/

I've seen that EM episode, you have to take these things with a large grain of salt guys FB is a smart guy but these tests hardly control all the variables etc and are only representative of their one test setup (in this case a BBC with huge heads, a huge intake and relatively short runners). Colder air makes more power, less heat transfer through the intake tract to the air, makes more power. Cold fuel may also play a part, but saying a cooler intake makes no difference is a bit misleading IMO despite what they 'saw' in the episode.

I've literally tried this backwards and forwards on the dyno. I've packed the float bowls entirely with snow and put the fuel can out in the snow in the back of my dyno cell to no advantage. Packing the intake with snow can and will add up to 50ft/lbs at the hit but ,Cold fuel does not make power Cold air does. It does however affect the AFR--which way is up for you guys to debate. Your car went quicker because of 1000's of different variables including the possibility of the cold fuel making the AFR slightly richer/leaner. I wouldn't lose any sleep over it. J.Rob

If the car was on the trailer outside....... wouldn’t the fuel in the cell be the same temp as the fuel in the can?

Thanks for the real world response !!!!

Thank you, some data to backup science and logic :P. If it made a significant difference people would be running A/C cooled heat exchangers to their fuel lines, and OEs wouldn't bother with plastic intakes (yes I know it can be cheaper but cooler air is actually one of the primary goals).

Same experience here. I don't think cold fuel does much of anything. It makes it slightly more dense and a little less likely to vaporize. If those things add power then that is a clue about AFR and perhaps octane or the type of fuel that your are using. Cold air makes power and cold intakes make power. Insulating the intake with wood spacers can add power. Building a turkey pan around the intake and filling it with ice will add power, intercoolers add power, etc.

You missed the part where i mentioned i was about out of fuel

Hey B3, you live in Kalamazoo, what ever happened to Mr. P-body, did he pass away? My memory is fuzzy on that

Mike lives over on the other side of the state. But he is fine, last i spoke with him. He and his wife winter down in South Texas, pretty sure they are down there right now.
Talked with him back last fall, was wondering how he was doing myself

Mr. P has a lot of knowledge i have "stolen" from him over the years !
hope he hasn't abandoned the board like so many others have.

Oh, thats good to hear