RodsINTOMG@aol.com wrote:
>
> In the above posting you say that the engines's heat is generated in the
> bearings, and while it is true that some heat is generated in the lower
> end...the major part of the engines heat is produced by the combustion
> process and that occurs in the combustion chamber and that is in the cylinder
> head.
Yes, I agree. Most of the heat occurs due to the combustion process,
but most of the problems due to heat occur in the bearings, valve train,
pistons, etc. This is what I ment.
Combusion is in the cyliders, not just in the head.
Look at it this way;
the piston, valves, and cylinders are what are actually in contact with
the explosion. Coolant touches the outside of the cylinders only, valves
and pistons never see coolant. But, they all touch oil, even the
cylinder walls. Oil is actually circulating THROUGH all the important
bits, coolant is just circulating AROUND the important bits.
So let's look at a real life situation. One exhaust valve is out of
adjustment, and that one cylinder is running too lean and too hot.
The piston's getting too hot, as is the valves, and this heat is
working it's way down the rod too. The oil is right there in the
thick of things, and if it can stay cool, it can keep the indivdual
parts cool too. The coolant has a slower reaction time, it can only
cool the rod, or piston, or valves, from a distance. The cooling of the
coolant has to get through the water jacket to the cylindar, or through
the head to the valves, or the block to the crank. A little hot spot can
develop within the engine that will be well isolated from the coolant.
When that rod/piston/bearing becomes too hot, it will have a much
easier, and quicker, path to dissapate the heat to the oil than through
the block to the coolant.
Also, oil needs more help to cool once it over heats. Imagine this,
you have a pot of water, and a pot of oil, on the stove. You heat
both to 200*F, and turn the stove off. The water will cool off much
quicker than the oil. Oil needs help to cool once it gets too hot, ie
a radiator.
Plus, lets say the engine really over heats. If we go the bigger
radiator route, when the water cools back down, the water is essentially
the same as it was (less some volume, of course). But the oil will
be degraded, it will never return to the same quality, and may even
have left burnt deposites on the piston rings and valves. And it will
have lost its lubricating properties on the way, scoring bearings, seals,
etc.
If we go the oil cooler route, the oil can keep lubricating, it will
be less likely to burn, and will recover to a better state.
One further example. Lets say for some reason one wrist pin is getting
too hot. To dissipate this heat to the coolant, the heat has to go to
the piston, then to the rings, then to the cylinder, to get to the water
jacket. To dissipate this heat to the oil, it's right there.
>The oil cooler is a good idea, but I think you will bet more bang for
> your buck by concentrating your efforts on the cooling system:
>water pump,
> radiator, thermostat, fan, hoses etc..
One oil cooler, two hoses, and an adaptor. Sounds more simple to me.
-Aron Travis-
"always in a automotive frenzy"
|