Advanced Engineering Tech - Single fluid engines.

was thinking about all the problems people have with over heating their engines when they start to boost them or are doing road courses and stuff. then i heard that oil coolers make a BIG impact on the tem of the engine, and often more than larger water radiators.

soooo why dont we just run oil cooled engines?? it works on bike and plane engines so why not in a car? surley the if a engine make X BTU's of heat then the 'cooling system', whatever that might be, needs to remove X BTU's of heat.

i know the old 911's where air cooled but wouldn't having the engine in the front help?

so what are your opinions??

Cheers

Chris.

The obvious is cylinder head cooling. Planes and bikes are air cooled and oil cooled on top of that deutz does it with diesl but it would be a good idea and a pricey oil changewas thinking about all the problems people have with over heating their engines when they start to boost them or are doing road courses and stuff. then i heard that oil coolers make a BIG impact on the tem of the engine, and often more than larger water radiators.

soooo why dont we just run oil cooled engines?? it works on bike and plane engines so why not in a car? surley the if a engine make X BTU's of heat then the 'cooling system', whatever that might be, needs to remove X BTU's of heat.

i know the old 911's where air cooled but wouldn't having the engine in the front help?

so what are your opinions??

Cheers

Chris.

The other issue is emissions. Porsche went for years with air/oil cooled engines but had to switch to water cooled just to get the engines emissions compliant. A air/oil cooled engine just cannot be "clean" enough to pass modern emissions testing. And once Porsche went water cooled, the H.P. also went up as the emissions came down.

The other issue is emissions. Porsche went for years with air/oil cooled engines but had to switch to water cooled just to get the engines emissions compliant. A air/oil cooled engine just cannot be "clean" enough to pass modern emissions testing. And once Porsche went water cooled, the H.P. also went up as the emissions came down.

why dose heat effexct emissions? i was under the impression there was an engine that heated the intake air to about 300 degrees C and had amazing efficeny (and thus emmissions). is this not the case?

anyone know the thermal propertise of oil?? whats its spesific heat capacity? just wondering if you could run a 'oil jaket' and use the oil to remove the ehat rather than water. obvioulsly you would need an oil cooler the size of a rad and a pretty hefty oil pump (thinking like a external multi stage one) but could it be done?

Cheers chaps

Chris.

not sure if this is why but i would suspect that water being far less viscous means that pumping losses are much less than they would be in a comparable oil based system, and also the water probably transfers heat more rapidly, so the change in temperature of the water across the water jackets and then across the radiator is greater. that means more heat removed per unit of area, smaller radiator in this case than an oil system, and more heat rejection by the cylinders.

Oil is prob. used in palne engines because it wont freeze at high altitudes? cooling is alot easer when its 40 below rather than 100+

Oil is prob. used in palne engines because it wont freeze at high altitudes? cooling is alot easer when its 40 below rather than 100+

Also bear in mind that the boiling point of water decreases as altitude increases. That combined with the fact that a water cooling system could easily weigh as much or more than cooling fins makes air cooling attractive for planes.

water is has been used in prop planes....what do you think the P51 ran?? ;)

also water has a specific heat capacity of 4200J/KG/K. i have no idea what oil is. anyone know?

as said before it has been used on bike engines and works. as for emissions, ditch the CATS and run Lean Burn heads that will operate at AFR of up to 20.0-1 (done by for on the CVH engine in the 80's but then scrapped as CATs came in).

dose anyone know why heat would effect emissions?

Chris.

I'm not sure, I drive a diesel I have no emmisions equipment :) But old airplanes ran ethylene glycol. Basically an alcohol coolant, not sure if there was any water mixed with it.

Also bear in mind that the boiling point of water decreases as altitude increases. That combined with the fact that a water cooling system could easily weigh as much or more than cooling fins makes air cooling attractive for planes.

thats what pressurised cooling is for.... just like on your car!

i think water will disperse heat better then oil

on the emissions side, water will make the engine run cooler then an air cooled engine, which means that the air that is inside the engine is more dense and will burn the fuel more efficiently and more of it, this is why Porsche started to get higher hp numbers out of their engines.

Water has a higher specific heat than anything. Meaning it has higher capacity to absorb and release heat per gram material.

^^^ not just any plain water. it has to be coolant. if you throw in some water in your car it will boil pretty quick.

^^^ not just any plain water. it has to be coolant. if you throw in some water in your car it will boil pretty quick.

nope.. plain water works great! with a 15psi rad cap you can increase your boiling point, plus you shouldnt be running hot enough to boil it anyhow.


The problems with plain water are
-Corrosion protection (isnt any)
-Freezing
-Overheating protection (protects incase something goes wrong)

^^^ boiling point for water is about 100degrees and the ls1's operating temperature is 210. so i do not see how you will not boil the water.

Water boils at 100 C @ 1 atmosphere, the ls1's operating temperature is 210 F but the coolant system is at a pressure higher than atmosphere which is why it has a higher boiling point.

^^^^ i actually used water in one of my cars so i could just get home because the rad was leaking. when i got home and opened the reservoir the only thing came out is a shit load of steam.

It is difficult to keep a system pressurized with a leak, so yeah the boiling point of the water wasn't as high as it normally would be and you were losing water.

Water alone has a higher boiling point than coolant/water mix.

As stated above, coolant is used as an antifreeze and as a corrosion inhibitor.
I believe nascar just runs straight water in their cooling systems.

And yes, added pressure greatly increases boiling point.
pv=nrt

why dose heat effexct emissions?


Cheers chaps

Chris.

hotter combustion, higher compression and lean AFMs increase the levels of NOx.

wouldnt really affect HC and CO, theyre only affected by incomplete combustion and rich AFMs

hotter combustion, higher compression and lean AFMs increase the levels of NOx.

wouldnt really affect HC and CO, theyre only affected by incomplete combustion and rich AFMs

Ahhhhh i see why now! thanks for that th0r :)

Chris.

Jet engines use a fuel/oil heat exchanger to cool the oil. Probably not a good way to do that on a car though, not enough fuel flow.

Most air/oil cooled engines use an excessively rich mixture to cool the tops of the pistons/combustion chambers...
They do not circulate oil through cooling passages in the cylinder and head to cool the engine, they just use fins on the head and jug, and pass the crank case oil through a cooler to keep

“also water has a specific heat capacity of 4200J/KG/K. i have no idea what oil is. anyone know?”

Water: 4.18 kJ/kg-K.
Engine Oil: 1.9 kJ/kg-K. (45% the specific heat of water)

“Water has a higher specific heat than anything. Meaning it has higher capacity to absorb and release heat per gram material.”

Not necessarily, water is up there but there are other liquids with a higher specific heat i.e. Ammonia with 4.84 kJ/kg-K. (water is 4.18)

“plain water works great! with a 15psi rad cap you can increase your boiling point, plus you shouldnt be running hot enough to boil it anyhow.”
“^^^ boiling point for water is about 100degrees and the ls1's operating temperature is 210. so i do not see how you will not boil the water.”

Boiling point of just water pressurized in a 15psi system boils at about 122C or 251F well below the 210 your thermostat opens at.

Enjoy!!!

Thanks s10 xtreme! :)

I remeber someone doing some testing with solar energy. they would use mirros to heat a 'liquid' to well over 100 degrees C and then use that to heat water to drive a steam turbine. i think they used Ammonia or something. They needed a VERY high boiling point and high Specific heat capacity. any ideas what they might have used?

Cheers

Chris.

Salt!

http://www.sandia.gov/Renewable_Energy/solarthermal/NSTTF/salt.htm

This may not be an advance engineering answer, but how about lack of relative air flow for a daily driver. Sitting in traffic, stop and go driving, etc. in the summer. Does this even make sense or am I over simplifying the situation?

This may not be an advance engineering answer, but how about lack of relative air flow for a daily driver. Sitting in traffic, stop and go driving, etc. in the summer. Does this even make sense or am I over simplifying the situation?

Far from it mate! it is a problem. Porsche managed to get it working though and lots of bike also have little problems with it. also by using ethanol rich fuels like E85 running temps should be reduced.

Chris.