Why Does Cold Fuel Make More Power? | Engine Masters

This time on Engine Masters, Freiburger, Dulcich, and Brule try to answer three main questions: Why does colder fuel make more power? How can you consistently keep fuel temps down, and what difference will it really make?

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[pdiddy]

I used to keep my bike in my house. On warm summer days, when I would start my ride, my tank was cold. It was a noticeable difference when everything got warmer. Also sometimes when getting gas, I could feel the cooler temp and I knew I was gonna have a touch more power. Been waiting for actual hard results for a long time. My buddies used to think I was crazy.

[sixtyharleyPittsburghPAP]

Drivers were adding "cool cans" to cars back in the 60's. They would use a coffee can and coiled copper tubing. Fill the can with crushed ice!

[charleshulsey]

Trans coolers are very useful for exactly this type of thing. Handy for heating and cooling almost any gas or liquid.

[Tommy-B.]

If it makes 10 hp it may be worth adding an evaporator type cooler to cool the fuel that runs off an ac compressor. Something like on the electric cars even. Not engine driven, and is basically a cooling block. They use it to cool the battery coolant.

[jlw]

Great stuff.. but I think the actual process is a bit different. The fuel actually absorbs heat from the air when it is mixed at the carb. The colder the fuel, the more heat it can absorb in that short trip from carb to cylinder. Colder air is denser so you get more in the cylinders and that is what actually makes more power.

[pauldanner]

My 1993 Mercedes 400E had a fuel cooler incorporated into the low side A/C line.

[ashtonmariefranklin]

With the ice cooler, add salt water. The salt will actually help make the cooler coils get colder. Also. You could do this test with liquid nitrogen, which boils at negative 320 defs F

[aps]

Old school Moroso Cool Can filled with dry ice for the win. Hottest summer days the car ran the top end the way it would early spring and late fall.

[LJ_Brooks]

You Guys Should Do An Episode Of The Advantages And Disadvantages Of Direct Fuel Injection And Super Coil Ignition

[upperroomtoo]

Back in 1982 my friend and I were building his 1970 454 Chevelle in high school. It gets hot in eastern NC in the summer and the carb would starve after the second or third run street racing. We got a Moroso "cooler can" I think it was called. Basically a coffee can that you ran fuel line through and filled with ice. It worked.

[chrispapa]

ive been cooling my fuel for a while now i did it to quieten my fuel pumps in my tank worked really well it also help with spark knock

[GerthebearBrady.]

AC coolant chiller from an EV used to chill the fuel would be cool. If you already had AC on the vehicle it could help keep the HP high.

[leeingle]

Interesting evaluation here. Since I have an LS3 with stock rails that are metal, they get hot, same goes for my LT1 GEN II when I road raced that car. They got super hot because they were thick and bolted directly to the intake manifold. All of the aftermarket rails are aluminum too so they heat soak easily but also dissipate heat fast as well. Wondering if cooler fuel would actually keep the fuel rails cooler when the engine is working hard and if there is a benefit to that.

[Atom]

The trans cooler idea is genius in my opinion. Now I wonder the reliability of it on a road car or if it will last under multiple runs at the track. But I definitely think it's worth testing for longevity.

[LobbySlayer]

Would be cool to see nitrous purges aimed at your fuel lines for street racers

[jcfabwerx]

Had to do that with a fast ez- efi setup. Fuel tank would get so hot you couldn't touch it. Didn't think about the power but I'll take the secondary benefits.

[kawicepticon]

I have made a fuel cooler on my jet ski spraying water from the pump through oil cooler that that was sealed in a box, then the outlet fed a cooper tube that was wrapped around the supercharger (tvs1320) which exited the hull...alot of work but it does go a consistent 2.5 mph . Speed on jetskis is expensive and this was quite cheap but took many attempts to be done cleanly .

[gunrunner]

My dad did the old school version of the cool can/ice can back when he used to drag race at the strip on the weekends, back in the early to mid 60's. They used to just use a coffee can or a paint can, mounted somewhere in the engine bay. They would run the fuel line from the gas tank to the can and use aluminum or copper tubing in the coil configuration inside the can, then route the rubber hose line from the can to the carburetor making sure that the line didn't get near the hottest parts of the engine. When it was time to make a run, they would fill the can with ice, put the lid back on it and make the run. It was never meant to be filled all the time, just for runs at the track. However, nothing says you can't put ice in it before a longer race. Today, I would use a mix of crushed ice cubes and dry ice. The ice can getup that was showed in the episode, is just the modern version of the hot rodders version. It's always been about two primary things, get the coolest air and coolest fuel you can going into the carb. I like the idea of the transmission cooler being used for fuel, but that whole thing has to be rock solid or yeah fuel everywhere.

[greggc]

It would be great to know how colder fuel affects basic MPI fuel injection. I'm thinking not as much due to the pressure drop from 50ish PSI to the vacuum of the intake.

[joeytacey]

Back in the 80s when I had a cool can under the hood... I would use that thick rubber insulation around the fuel line all the way up to the carburetor... The type you see on home air conditioner