Oil as a coolant

[rmchambers]

I was wondering if it would be possible to use fuel oil as a coolant.  I know the transformers on the poles outside use oil as a coolant.

What I was thinking would be that the fuel oil wouldn't freeze in the winter, wouldn't cause rust.  Would it thermosiphon as well as water?

Assuming you could rig up a low coolant level shutoff you could pre-heat your fuel and take it from the coolant loop and use it right as it comes off the hottest part of the engine.

Just a thought that popped into my head as I was mowing the yard today.

Robert

[unimogr]

This is something that would do the job I think:

http://www.evanscooling.com/main27.htm

Jason

[aqmxv]

I have to say that I find the idea of having fuel in the water jacket a little scary - listeroids are a little too prone to head gasket leaks.  Get a leak in to the cylinder and you could easily get a runaway.

You'd probably have to press the liner out and change the o-rings as well - they're likely not up to continuous immersion in fuel oil.

As for the theoretical practicality of it - it'd probably work fine, as long as the flow rate through the inlet and outlet pipe fittings is high enough - the water jacket itself is very voluminous.

[rmchambers]

Ah yes, I didn't give much thought to the runaway scenario.. very bad.  The coolant replacement that the second poster listed looks interesting, one could use that and a heat exchanger arrangement and limit any corrosion in the water jacket.  Not quite the same thing as heating your fuel directly but probably a whole lot safer.

Thanks

[phaedrus]

I have read somewhere that silicone oil has been used as an engine jacket coolant. It's pretty 'spensive. I suspect that it would require a coolant circ pump. The Si oil is obviously non-combustible.

[rmchambers]

I wonder if something like Dot-5 brake fluid which is silicone would do?

Why would something like this not thermosiphon?   surely if it gets warm it expands and becomes less dense and lighter and would try and float upwards?

Another question, I see references to the inner parts of the water jacket being painted with Glyptal, what kind of paint is this by the way and who sells it?  Is it some sort of epoxy that bonds to the metal?

Robert

[aqmxv]

I can't speak to sources for glyptal, but I can answer the thermosiphon question.

Thermosiphon has another (more accurate name): gravity circulation.  It depends on the change in density (specific gravity) of the fluid when heated.  Hot air (and hot air balloons) rise because they're less dense than cold air.  Ditto smoke in a chimney, or hot water in a cooling jacket, if you give it a chimney (mostly vertical pipe above the jacket outlet).

To answer the question of thermosiphon with a particular fluid, you have to find out what its change in density is over the expected operating temperature range.  Larger change is better.

Now for the bad news:  Brake fluids are usually designed to have a small change in volume over wide ranges in temperature (to avoid hot brake locking, burping master cylinders, etc).  You'd probably need a significant additional vertical pipe run to get enough motion to do the job.

[dkwflight]

Hi I've been reading the Evans site with interest since one of my goals is tur run the 'roid as hot as possible, for a number of reasons.

The price is putting me off $32. +shipping per gallon.
They say the stuff is more viscus than antifreeze, thicker. So you will need a pump.  Finding a pump that can stand the hi temps is a problem. The ability to run at up to 375f without a pressure cap is a plus for me. maybe the GM-90 pump?
Dennis

[Doug]

Robert:

Glyptal 1201 is an electrical grade paint

http://www.glyptal.com/1201prolll.htm

I use it for everything. Its realy nice for painting the insides of engines and gear boxes with becuase heat and oil won't bother it.

This picture will give you an idea what it looks like and if you notice in other pictures some of the Indian parts were also coated from the makers with a product like 1201. Many engine companies like OMC used 1201 on parts....
 
http://www.putfile.com/pic.php?img=3978442

Doug