What happens when you flow coolant fast through a radiator/engine block? There is no heat transfer. What happens when the air passes through an intercooler too fast? The intercooler can't cooler the air.
I'm sorry, but I totally disagree. I've heard that said many many times, and it just can't be right. As I mentioned before, industrial heat transfer is one of the things I deal with professionally. Higher velocities through a heat exchanger (such as an intercooler or a radiator) always improve heat transfer. I guess this argument should be saved for another thread, but I just can't help myself
Now do I believe that higher flows result in higher temperatures? Sure, that makes sense, I can explain that a few different ways. But what I think has happened is that someone took out their thermostat, saw a higher temperature, looked for an explanation, and came up with "not enough time in the radiator to cool off the water". And they came to the wrong conclusion, and it got repeated enough times to become the common wisdom and everybody believed it. Notice I'm not arguing with the result, that they saw a higher temperature, just the reason why there was a higher temperature.
Same applies to the bearings, increase the pressure, you will have more flow across/through the bearings. There will be no transfer of heat when the crank spins. And the bearing heat up.
Now this is something I don't have any professional experience with, but my intuition tells me that it might not be the higher flow that is the problem, but maybe it's the increased turning resistance of the crank. Like that other link you posted mentioned, and their example of trying to run through a bool of water vs a pool of honey. If there is more resistance to the crank turning then more heat is generated due to the increased friction. So if the additional cooling provided by the higher oil flow is less than the extra heat generated by the increased friction, then the bearing temperature would go up. That explanation would make sense to me. A lot more sense than saying the higher flow can't carry away the heat, which doesn't feel right. Not saying that this is the mechanism involved, just a hypothesis. It might be something else. Again, not saying that the bearing temperatures don't go up, I'm just looking for a reason that makes sense to me.
Nice link, I totally agree with the whole thing
Their talk on cavitation is what I am familiar with - pump suctions, and the resulting pump damage when the bubbles collapse. No mention there of bubbles on the pressure side of the system. BTW, to me, that subject leads me over to PCV systems. Contamination of the oil directionally pushes you towards a cavitation problem, more gasoline and such in the oil will increase its tendency to form bubbles in the pump suction. Having a functioning PCV, and pulling a decent vacuum on the crankcase, will help vaporize that crap, and degas the oil, helping to reduce the tendency of the oil to make bubbles in the pump suction.
On pump types, sure, gerotor much better than our style pumps
Here's a thought: our pumps, with the straight cut gears, are functionally equivalent to a Roots blower, which also are known for their low efficiency. If someone made oil pump gears with a twist to them, or made an actual compressor type lobe (think Eaton twin screw type supercharger) our pumps would get a LOT more efficient. That would be sweet... just pop the old straight gears out and slide the new twisted gears in. Probably cost too much to make though. I'd buy it if it was available! A lot simpler than welding two timing covers together to get the 3800 gerotor pump.
This stuff is getting too complex.
naw, this is fun ain't it?
John
