Quote:
Originally Posted by 71RS/SS396
I'm going to disagree with your engine builders opinion of controlling the temp with the fans, while that will work at low speed in traffic, it will not work when moving at highway speeds with airflow through the radiator. Fwiw I have a 750+ hp enine that spins to 8K and it cools just fine with a stock GM pump and 195* thermostat. Imho there's no need for fancy high flow water pumps, running the engine too cool is not good for it either. Ideally you want it warm enough to get the oil to get to 212* to boil out the condensation.
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My builder's opinion/experience is way more complex than what I typed above. I didn't want to type a long diatribe, and most don't want to read it. I don't claim to know all he does, but he agrees you need oil temp. But oil temp runs considerably hotter than water temp, and (in his opinion) you don't need or want that much water temp.
A little more info... My motor has about 11.5:1 static C.R., and the cam timing provides for about 220 lbs cranking compression. I use 92 octane gas. I have a 6 speed & 3.55 gears, so in "touring" mode, I am at about 1500 rpm at 65 mph. Another factor is I can sometimes get stuck in traffic on a 90 degree day, and with a black car, want to be able to run the A/C. (What is the point of having A/C if you can't use it?) With this setup, we want to control the temperature as much as possible. His biggest concern is detonation. And I think we can all agree that higher combustion temps lead to detonation.
My car has the Vintage Air Frontrunner system, which comes with the Stewart pump. Do I need it? I don't know, but as long as it was engineered that way, I will run it if I can.
My motor is new, with more static & way more dynamic compression. I also have a new larger radiator with larger fans. And now the "new" pump. Dialing this in is a learning experience for me. I have always run a 'stat in my cars, and read years ago you needed the restriction the 'stat provides to create higher pressure in the block to prevent hot spots from locally boiling coolant in the heads. I had installed it with the new pump, but it obviously didn't do well with that restriction. I can control the fans with my ECU, and (so far) it seems to work well.
Drove about 60 miles on Saturday... it ran at 150 in 55 degree weather, and about 165 when it warmed up to 75. Drove it about 50 miles yesterday in 80 degree weather, sometimes with the A/C on, and it never went over 180. I am very happy when the gauge is under 200.
Time will tell about the city vs. highway speeds, and 90 degree days with A/C. But so far, so good.
And thanks for weighing in!
Bill