Cooking oil as coolant?

[Valley Rock]

If I was to run oil to cool for some reason in this day and age I would cut half the fins off the water pump and remove the thermostat, the thickness of oil would be your thermostat, and trying to pump it in a hurry would aeriate it .

 

[87cr250r]

There are a couple of major drawbacks to running oil. It's very viscous and tends to flow laminarly instead of turbulently. This means boundary layer are very thick and they act as insulation preventing heat transfer.

Oil has a very low specific heat. More oil has to be pumped through the system to achieve the same heat rejection. Due to the high viscosity there will be much friction to overcome.

As for trimming the impeller, oil has a lower specific gravity than water so a centrifugal pump will generate less pressure when pumping oil. A larger diameter impeller would be required to generate the same pressure vs water.

Modern coolants are quite effective at preventing corrosion but you need to start with a clean engine. Do flush with acid before filling with coolant. If the system has been contaminated with oil you'll need to flush with a detergent before the acid.

 

[HDN]

There are a couple of major drawbacks to running oil. It's very viscous and tends to flow laminarly instead of turbulently. This means boundary layer are very thick and they act as insulation preventing heat transfer.

Oil has a very low specific heat. More oil has to be pumped through the system to achieve the same heat rejection. Due to the high viscosity there will be much friction to overcome.

As for trimming the impeller, oil has a lower specific gravity than water so a centrifugal pump will generate less pressure when pumping oil. A larger diameter impeller would be required to generate the same pressure vs water.

Modern coolants are quite effective at preventing corrosion but you need to start with a clean engine. Do flush with acid before filling with coolant. If the system has been contaminated with oil you'll need to flush with a detergent before the acid.

That was an engineer's response if I ever read one. What's the Reynolds number of oil running through a deuce cooling system? (Just kidding!)

That was a good explanation of why oil isn't a practical coolant for this application. I believe oil is only really used as a coolant for machining and high-power computers as @Redleg130 mentioned. I believe some server farms are actually getting into submerging computers in mineral oil instead of using CRAC units for cooling the entire room. I think it also uses less energy to oil-cool these things. For those who are interested: https://performancepsu.com/mineral-oil-pc-cooling/

 

[87cr250r]

Veggie oil also turns in to paint as it oxidizes. That makes your cast iron pans non-stick but it's not so good for engine surfaces. Vegetable oils were the first alkyd enamels.

 

[Guyfang]

Some transformers here in Germany use oil to cool them. Nasty stuff.

 

[HDN]

Some transformers here in Germany use oil to cool them. Nasty stuff.

There's that too, also done in the US. The power utilities actually have dogs trained to smell for oil leaks during substation PMCS since they're not all obvious.

 

[cwc]

A silicone oil formulated for low temperature heat transfer (e.g. Dow Syltherm XLT) would address some of the issues, e.g. viscosity and the objectionable odor of some fluids. Still there is a penalty vs. water in heat capacity and thermal conductivity. So it takes more circulation to provide equal performance, and as noted the water pump will not perform as well as with water. Part of the solution could be to spin the pump faster since it won't be as prone to cavitation.

I would be concerned about a runaway condition with combustible coolant in the event of a head gasket leak. It seems you would want to run with the coolant unpressurized, vented to atmospheric pressure. Might need a larger expansion tank since the oils tend to have higher thermal expansion coefficients.





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[Mullaney]

Some transformers here in Germany use oil to cool them. Nasty stuff.

.
Here in The States, substation transformers were filled with oil that had PCB's (Polychlorinated biphenyls) in them. UNISON was a large company here that reworked thousands - maybe more - of those transformers to a new grade of oil to eliminate the carcinogenic chemical compounds. We printed metal tags to note what was reworked. They spent hundreds of thousands of dollars just on the tags with us back in the late 70's and early 80's.

.

 

[msgjd]

Has anyone ever heard of using cooking oil as coolant in the radiator? .

I was in heavy industry for a bit of time.. Certain production machines I worked on with non-pressurized coolant systems to keep "raw" product at a consistent high temp set between 250 and 600F during the process , certainly used a straight-weight oil as the coolant which was pumped at velocity through heat exchangers hooked to water storage tanks, aka cooling towers.. Vegetable oil certainly could be substituted in those machines but I would be leery of it building up its atypical surface coating.. Early internal-combustion engines were oil-cooled .. Early "diesels" ran on peanut oil, castor oil, and other plant-based oils back when there was no diesel fuel as we know it today.. WW1-era aircraft and early race cars were lubed by castor bean oil and the age-old company "Castrol" used it in their formulas.. Plant-based oils were, and are, expensive to produce, thus the petroleum industry had surpassed the veggie-lube market by the 1920s ..

Oil of course has a very high boiling point, some more than others.. The only issues I can see of using WVO (or new) in a truck cooling system is cold temperature gells it .. Gel temp depends on the fat and glycerine content, which of course varies as to what was cooked in it.. The other issue is, WVO gets very sticky over time and forms a tough film on surfaces wherever exposed to air for a length of time.. Thus I spray it on with a "shutz gun" as vehicle undercoating. . Since a deuce system breathes during expansion and contraction, I would be concerned of what could be going on in the upper radiator's exposed surfaces, especially if the truck sits a lot.. Heat transfer is also a slower process with any oil.. As much as I run WVO fuel mixes in just about every compression-ignition engine on my property for 18 years now, I personally would not put it in any radiators, no matter how much I could filter and centrifuge it.

 

[msgjd]

However one thing I've heard from some vets, when drunk, they would drive their deuce until it nearly ran out of fuel and they took turns urinating in the fuel tank to get back to base.

Haha I had heard it at times over the decades, and it was always just a joke or someone pulling someone's else's leg... The theory is; since pee is assumed heavier than fuel, the fuel level would rise and suction tube could grab fuel again. In my experience guys said it as a slam against 5T and 10T fuel tanks, there would still be about ten or so gallons sitting in them when they died... But of course, I am sure pee would be plausible only when vehicle was sitting still on the level and the liquid was not sloshing .. But I highly doubt it actually will get a vehicle to move much... However, why not dump a bunch of clean rocks in the tank instead ?? Where's the Mythbuster's when we need 'em?

 

[ToddJK]

Haha I had heard it at times over the decades, and it was always just a joke or someone pulling someone's else's leg... The theory is; since pee is assumed heavier than fuel, the fuel level would rise and suction tube could grab fuel again. In my experience guys said it as a slam against 5T and 10T fuel tanks, there would still be about ten or so gallons sitting in them when they died... But of course, I am sure pee would be plausible only when vehicle was sitting still on the level and the liquid was not sloshing .. But I highly doubt it actually will get a vehicle to move much... However, why not dump a bunch of clean rocks in the tank instead ?? Where's the Mythbuster's when we need 'em?

I'm glad I'm not the only one who's heard it, lol

 

[Karl kostman]

Two big issues I see in using cooking oil a coolant. Oil retains heat very well as opposed to conventional coolant which displaces heat very well as its pumped through the cooling system. How are you going to cool the oil down? The water pump is NOT called an oil pump, can it even circulate oil? How is your thermostat going to handle OIL as opposed to coolant?
I wouldnt do this is somebody paid me to do it!