Cool KJ

[tjkj2002]

So why doesnt everyone use oil coolers if the oil cools the engine better than the rad does?

The cooling system on modern engines is mainly used for 2 things--1: allow the engine to heat up to operating temp FASTER-2: to maintain correct operating temp.It does help cool but to a point,just remember that friction also causes heat,add oil,less friction=less heat.If a engine losses all of it's oil what is the first thing that happens? It overheats,then locks up due to the expansion of the pistons was to great for the cylinder walls,keep the friction down and the heat stays down(with the help of a correctly operating cooling system).That's why desiels hold more engine oil(produces more heat) and race cars use engine oil coolers.

 

[sevenhelmet]

1.) The oil reduces friction so parts don't rub together and things don't bind up due to heat expansion. This is cooling in a sense as it prevents lots of heat from building up in the first place.

2.) The water/coolant mixture absorbs and carries heat (water is an excellent reservoir for heat energy.) This is heat from the block due to combustion and the friction that still does occur there in spite of the oil.

3.) The RADIATOR keeps the engine cool by exchanging the heat of the water/antifreeze with the relative coolness of the air flowing through the vanes.

4.) The thermostat regulates water flow through and/or bypassing the radiator to allow the engine to warm up after starting and keep the whole mess running at a relatively constant temperature, which equals good news for Mr. Engine.

Most modern engines are very temperature stable, which is PARTLY why engines last longer than they used to. If you see any deviations from normal operating temp, your thermostat is most likely the cause (barring ridiculously high or low ambient air temperatures.) And yes, I DID take thermodynamics.

 

[Tokyojoe1965]

Driving in the Rocky Mountains and trying to maintain 65-70 mph you would think the temp would go past the halfway mark. Nope! Mine has never gone past that halfway line. *Knock on Wood*

I am sure I have jinxed myself now. What's the time limit for a jinx? peepwall.gif

 

[o8k]

1) Sevenhelmet, what happend to your Cat w/ the LimeSkin helmet? That rocked!

2) My jeep never busts 220F but it will get there often when its hot and im up-hill'in. My needle shows 220F at about 3/4 towards the H area. and starts to climb off 1/2 at about 210 ish. (using scangauge as my temp #s)

 

[Marlon_JB2]

TonyCRD, that's the viscous heater. Since the diesel is more effecient, it produces less heat, so the viscous heater warms the engine up faster so the passenger compartment can get *some* heat when it's cold outside... and don't idle the engine... ugh... when that temp gauge drops like I said previously, so does the heat coming in.

 

[xxdazxx]

http://www.jeepkj.com/forum/showthread.php?p=318757#post318757

 

[JeepJeepster]

Wait, tjkj said that diesels put off more heat and marlon said they put off less.

I always thought oil was to lubricate and engine so that it doesnt wear out and seize up, not over heat.

 

[Marlon_JB2]

Wait, tjkj said that diesels put off more heat and marlon said they put off less.

I always thought oil was to lubricate and engine so that it doesnt wear out and seize up, not over heat.

I actually meant to say that less energy is wasted as heat. I don't know the specifics.

 

[Ry' N Jen]

Good day,
TJKJ is totally correct, oil does the majority of the engine cooling. Look at The Volkswagen Auto group. every engine that they produce has an oil to water oil cooler installed. Very efficient. In fact more efficient than an air/oil heat exchanger (Like a conventional radiator)

 

[o8k]

relative to gasoline, diesel has more carbon chains in it, is haevier and has more btu,s by vol. in addition to this, the combustion cycle of a diesel will convert more of this heat energy into mechanical energy than a gasser aka more efficent. ill state this part as fact best ive gathered ovr the years... on to the guessing...

not to be confused with total system efficentcy, where gassers debatibly win. this total efficency debate is quite another topic tho so ill leave it at that.

weather or not the more heat being converted to mechanical energy makes up for there being more energy in the fuel or not, thusly running hotter or colder, i dont really know ive heard may arguments on both sides, since there is more energy my other guess is, less fuel in combustion cycle to do the job....

my guess is engine wont generate as much heat, as more heat converts to mechanical energy. the extra energy in the fuel means less in the combustion cycle rather than same ammnt and more heat made. engine will have higer combustion temps but lower exhaust temps,, clasical heat engine theory, effieceny = difference in heat input vs heat output.