Is one type of coolant better for heat transfer?

[Elkins45]

Mowing in the spring when stuff is pollinating is a real ordeal for my Kubota tractor because even with a pre filter screen in place the radiator gets covered with pollen and the engine temperature starts heading for the redline. When it’s really bad I have to go back to the garage every 3-4 passes to sweep off the screen and blow out the radiator.

Is there any particular formulation of coolant that is more efficient at transferring heat than the others? I’m not worried about antifreeze properties because I can switch coolant easily between spring and fall, but a more efficient coolant might keep me in the field longer between cleanings.

I doubt there’s enough of a difference to matter but it’s easy enough to ask.

 

[ripcord]

No, they are all ethylene glycol based (except for the less efficient "safety" type which is propylene glycol) so are all the same in terms of heat transfer.

Reducing the coolant concentration to 70% water will give a marginal improvement as plain water is more efficient.

 

[Chris142]

The secret to a cooling system is air through the radiator. No coolant will work without air flow. Its not uncommon to have to flush out a radiator daily on tractors and such. The bigger stuff will ocasionally reverse the fan to blow stuff out of the core.

 

[ripcord]

You probably know better but by chance are you running the engine at reduced RPMs?

 

[Coolant Kid]

Yes, the ones without silicates will transfer heat the best. This is because silicates coat the cooling system passages and blocks heat transfer like a thermal blanket. Just use either Napa 1EXT or Peak Global Lifetime and you're good.

 

[ka9mnx]

Best coolant is straight water. Ask any old school racer.

 

[eljefino]

What Chris said. The radiator isn't rejecting the heat. The heat is making it to the fins well enough.

 

[Cujet]

As mentioned above, water is best for heat transfer. Using a 30% concentrate of antifreeze seems to be a good way to maximize heat transfer while still having corrosion control and halfway decent freeze protection.

Redline Water Wetter (or similar) is a product that can help heat transfer by allowing the use of straight water, while still providing water pump lube and some corrosion protection. Supposedly it improves the water's surface contact when boiling temperatures are reached, such as a hot cylinder head. I've used Water Wetter in high output race car engines with success.

WaterWetter®

Unique agent for cooling systems that doubles the wetting ability of water

www.redlineoil.com

But in the end, it seems like you need to fabricate a low restriction filter for your radiator. And of course, ensure it is clean inside and out.

 

[Elkins45]

What Chris said. The radiator isn't rejecting the heat. The heat is making it to the fins well enough.

True, but a more efficient transfer fluid takes more of the heat from the block to the radiator, even if the radiator isn’t working as effectively. And it holds more of the heat in the solution.

Like I said, I doubt the fluid would make enough of a difference to matter, but at least in theory it would make a difference,

 

[kschachn]

Ethylene glycol has a somewhat higher heat transfer coefficient than propylene glycol but water is far better. If this were my vehicle I'd run the minimum coolant concentration that the manufacturer recommends but still allows for adequate freeze protection. Those water wetter products do next to nothing when used along with coolant, they are most effective with plain water. But coolant provides other benefits and I'd never use straight water in a passenger engine.

Continue to make sure the engine passages aren't caked with deposits and that the radiator is clean both inside and out.

 

[tmorris1]

We have used Engine Ice coolant in dirt bikes and it seems to work a little better than regular coolant. Running slow single track, the radiator fan seems to kick on less.

 

[Marcozi]

Try running straight distilled water during the summer.

 

[eljefino]

True, but a more efficient transfer fluid takes more of the heat from the block to the radiator, even if the radiator isn’t working as effectively. And it holds more of the heat in the solution.

Like I said, I doubt the fluid would make enough of a difference to matter, but at least in theory it would make a difference,

Yeah, a small difference since the wet side is working properly.

The air side can only reject a minimal amount of heat, with a temp difference of ~120'F between coolant and air. The two ways it can become more efficient are to get hotter still so there's a better temp delta, or to improve airflow with a faster fan or by removing the insulating dust.

I get the question, if your engine is 230' and your rad 220' is there something that can cool better so the engine will be 225' instead. As you wrote, there's not much to gain.

 

[ripcord]

It's this a gas or a diesel machine? Does the tractor have a mechanical fan with a clutch? If yes, have you verified it's functioning correctly? Is the engine running at full RPMs while working?

Maybe you can find a fan with more or bigger vanes to try and get more air flow.

Another idea is to use magnets to stick some window screen over the outside of the grill to catch some of the pollen. Then you can just jump off and shake it out once and a while.

 

[eljefino]

Would a furnace filter be a better pre-filter?

 

[jeffy876]

No, they are all ethylene glycol based (except for the less efficient "safety" type which is propylene glycol) so are all the same in terms of heat transfer.

Reducing the coolant concentration to 70% water will give a marginal improvement as plain water is more efficient.

Theres also the eco-friendly glycerin based antifreeze. A lot of European cars are using at least some glycerin in the coolant these days.

Btw, if you're going to use straight distilled water make sure every trace of anything that isn't distilled water is totally flushed out or stuff is going to corrode. There's corossion prevention additives in coolant, and distilled water is pure, but if you don't have completely pure distilled water and there's salts still in the system but without the full strength corossion protection additives mixed in as well youre going to get a lot of corossion.

 

[FTTSHO]

Best thing you can do for maximum cooling is to keep your radiator fins clean and free of debris. Keep it clean just like the day it left the factory.

Radiators get hit with tar, bugs, dust, dirt, and etc. Clean the radiator fins to maximize heat transfer. Also, don’t get any paint on the radiator fins.

Get some purple power degreaser. Close to full strength, spray the degreaser on the front of the radiator. Let it sit to melt all the bugs and dirt for 5 minutes, then rinse it off with water with some pressure from the engine bay side. You won’t have to remove the radiator to do this on most cars.

Also, keep your radiator area behind the bumper clean. There will be a lot of leaves and dirt in there if you’ve never cleaned it out.
Coolant won’t make a difference. All coolant cools the same. Just make sure there is absolutely no air in the cooling system.

However, the ratio of coolant/water can make a slight difference. More distilled water and less coolant (about 70/30) will make the heat transfer better. Just change the coolant out when you have to, and don’t let it get old and coat the inside of the radiator with gunk. That will definitely reduce heat transfer.

 

[Elkins45]

It's this a gas or a diesel machine? Does the tractor have a mechanical fan with a clutch? If yes, have you verified it's functioning correctly? Is the engine running at full RPMs while working?

Maybe you can find a fan with more or bigger vanes to try and get more air flow.

Another idea is to use magnets to stick some window screen over the outside of the grill to catch some of the pollen. Then you can just jump off and shake it out once and a while.

Diesel, and the fan is directly attached to the crank. There's a pretty good screen in front of it already, but adding another wouldn't hurt.

The two ways it can become more efficient are to get hotter still so there's a better temp delta, or to improve airflow with a faster fan or by removing the insulating dust.

Rigging up some sort of gizmo that sprays water across the radiator would help as well. Evaporating water carries away a lot of heat.