Re: Running engine without thermostat

Posted by Gerald J. on March 26, 2005 at 13:17:43 from (67.0.96.184):

In Reply to: Running engine without thermostat posted by Willy P on March 25, 2005 at 18:59:25:

Other than engine efficiency and life there's no need for the thermostat.

With the combustion temperature several hundred degrees higher than the coolant temperture, running the cooling system cold takes more heat from the combustion and so reduces the output of the engine. So the cold engine takes more fuel for the same load. For this consideration it would be nice to run a coolant temperature a couple hundred degrees warmer, but pistons and rings can't yet hack higher temperatures. Ceramic pistons, cylinders, and rings may allow that higher coolant temperatures in the future. Essentially, the hotter you can run the engine AND still lubricate it (there's be big rub) and take away the waste heat (in a diesel more than 2/3 of the heat energy in the fuel goes to the oil and coolant) the better.

Then there are the side effects on the oil. Water is a combustion product of hydrocarbon fuels (from burning the hydrogen). Cool cylinder walls condense that water that then can run into the crankcase. Inburned fuel follows. Both affect the lubricating oil adversely. Makes sludge and that sludge blocks passages and the water and fuel parts of the "lubricating" oil don't lubricate well so bearings wear. On top of that water with combustion products like those from burning a bit of sulfur makes sulfuric acid that eats bearings.

Running the engine as close to water boiling as possible (180 or 210 degree thermostat with a closed and pressurized cooling system) boils the fuel and water OUT of the oil getting far better bearing and oil life.

Running an engine without a thermostat is ABUSE, don't do it. If the engine doesn't heat up the thermostat isn't closing properly. Put in a new thermostat. If the engine still doesn't warm up, restrict the air flow through the radiator in the winter.

Gerald J.

Follow Ups:

Post a Followup Name: E-Mail: Subject: Comments: Optional Link URL: Link Title: Optional Image URL: Email Notification: If you check this box, email will be sent to you whenever someone replies to this message. Your email address must be entered above to receive notification. This notification will be cancelled automatically after 2 weeks.

TRACTOR PARTS	TRACTOR MANUALS

We sell tractor parts!  We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today. [ About Us ]