12:1 E85 turbo build
#87
Higher pressure makes the cooler cool more oil. More mass flow, its just going to have to be a higher quality cooler. AND honestly once you get up to the oil cooler temperature the oil pressure should have dropped enough to not really use much regulation from the regulator.
Buy the billet gear, breaking oil pump gear at 24PSI and 6000rpm sucks! I've been there...
#88
Ok, let me stop you there. More pressure through the same area is more velocity and most likely more volume. However the increased speed means oil will spend less time in the cooler, so not true about the cooling more oil. In addition higher pressure means higher pressure drop across the small lines and coolers and so on. I mean ultimately it probably doesn't matter. As long as the oil cooler is not JB-welded together, most of them will be able to take 150PSI on the low side and unless there is an external pump (Which in this case there is not), I highly doubt you will see that much pressure.
#91
On reasonable scale the time dependent heat transfer is negligible in heat exchangers. If you have otherwise identical 10 row and 5 row heat exchanger and fix the flow velocity through both heat exchangers such that the 10 row velocity is half the 5 row (this makes the mass flow between the two exchangers the same) and they are in the same environment with the same same oil inlet temperature then the oil outlet temperatures will be the same even though the oil spends half as much time in the smaller cooler. This only works if both coolers are already in steady state and are both able to reject the same amount of heat. Of course thats not a real life scenario, but one while illustrates the point clearly. The reason cross flow rads with their longer coolant paths cool the coolant more is not because the coolant spends more time in the radiator, its because the coolant covers more distance in the radiator.
#92
I know if the flow velocity is fixed, the area added doesn't really add more cooling. However back to our discussion, laminar and turbulent flow do effect the heat transfer characteristics of a fluid, how much will be hard to tell, but they do. If you go from say 50PSI to 100PSI through the cooler, you could potentially double the velocity.
Now that I think about it we are both wrong about this, doesn't matter where the regulator is, any pressure behind it from pump through will be the pressure at the regulator. It is a static closed system!
Now that I think about it we are both wrong about this, doesn't matter where the regulator is, any pressure behind it from pump through will be the pressure at the regulator. It is a static closed system!
#93
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Running higher oil pressure than necessary to lubricate the engine robs horsepower, generates excess wear in the pump and the crank drive surface, and creates excess heat. Use what pressure you need with a bit of cushion and don't go nuts.
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