Radiators, thermodynamics & fluid-mechanics questions

[fitterski]

You could mount heat exchangers somewhere on the blower like a snowmobile. The exchanger on my 900 Arctic Cat was surprisingly small for 150 HP.

Good news man! I like to hear things like this :dance1:

The higher the temp diff. the more efficient the rad. Thermostat is 192F & OAT will be about 5F. The engine is actually the smoothest and safest place (once blew the chute deflector right off, it landed 70 feet away in the snow). With a small 3d footprint of around 17x12x8 I expect to bolt the 'cooling pack' to the engine with reasonable integrity. If it's not enough I can always upgrade.

BTW if anyone is interested 1" copper plumbing fittings slip right into the 7/8" rad hose like it was a glove ...at 1/100 of the price of some *rad-fittings* that I've seen.

 

[ArlyA]

$10 says there is a reason that manufacturers are not doing this on current blowers. Like snow sticking everywhere, you don't want it.

You could mount heat exchangers somewhere on the blower like a snowmobile. The exchanger on my 900 Arctic Cat was surprisingly small for 150 HP.

 

[Dave M7040]

Why bother with a rad at all. Solve your cooling with software.

Modern engine and their computers manage to avoid damage from excessive heat by rotating which cylinder is allowed to work. The non working cylinders are cooled by air passing through them.

Cadillac, on their Northstar V8 of around 2002, was the first consumer gas engine to provide this limp home capability for their owners.

Formula one engines, clearly the most sophisticated in the world, keep their cool in the same manner when sitting on the starting grid.

Diesels work this self cooling even better as their is no air throttle so easier air movement through the engine.

My third year thermodynamics course taught me that NPSH is a critical factor in pumping fluids, especially for cooling. That is why the suction hose is larger than the discharge hose.

When plumbing multiple heat exchangers into a system (i.e. radiators) best engineering practice would be to use the "reverse return" piping method to keep flows naturally balanced.

Many diesel engines are designed as an air cooled prime mover so get one of those and it will work in the hottest weather.

Dave M7040

 

[Agvg]

Or get a Deutz air cooled diesel and have no worries about cooling.

 

[texasranger556]

Why bother with a rad at all. Solve your cooling with software.

Modern engine and their computers manage to avoid damage from excessive heat by rotating which cylinder is allowed to work. The non working cylinders are cooled by air passing through them.

Cadillac, on their Northstar V8 of around 2002, was the first consumer gas engine to provide this limp home capability for their owners.

Formula one engines, clearly the most sophisticated in the world, keep their cool in the same manner when sitting on the starting grid.

Diesels work this self cooling even better as their is no air throttle so easier air movement through the engine.

My third year thermodynamics course taught me that NPSH is a critical factor in pumping fluids, especially for cooling. That is why the suction hose is larger than the discharge hose.

When plumbing multiple heat exchangers into a system (i.e. radiators) best engineering practice would be to use the "reverse return" piping method to keep flows naturally balanced.

Many diesel engines are designed as an air cooled prime mover so get one of those and it will work in the hottest weather.

Dave M7040

Good luck modifying the software in a 12 valve!

 

[farm boy00]

How much space are you really going to gain by doing 2 smaller radiators versus the factory radiator?? And the factory one is already designed and if it gets too cold put a cover on it

 

[Mace Canute]

Heat exchangers are generally throttled on the outlet rather than the inlet.

This keeps the fluid in the heat exchanger at a higher pressure, therefore gases are less likely to come out of solution, therefore you get better heat transfer, less chance of gas-binding of the heat exchanger.

Source: I was a nuclear-trained submarine mechanic for twenty years.

I don't think anyone who doesn't under stand this should be fooling around redesigning the cooling system.

 

[Egon]

It's also desirable to keep full liquid contact in an exchanger so no hot spots can develop.

 

[fitterski]

Or get a Deutz air cooled diesel and have no worries about cooling.

That's what this engine is replacing

BTW just because it's air cooled doesn't mean there's no need for temp. control. It's just that on a Deutz you modulate the air flow instead of the liquid coolant.

 

[fitterski]

Diesels run better at their rated temperature.

That's why Cumins raised the thermostat to 192F. That BTW is what sums everything up, the coolant in the block should never be much above thermostat temperature. Once the engine has warmed up, being below it could happen with a thermostat stuck open. I will have precise coolant temp as well as EGT indication to monitor.