<VV> Re: Porsche cooling

[Crawford Rose]

It is unfortunate that Porsche has such a good reputation for cooling 
because it isn't so much truth as belief. When I was 19 y.o. I owned a 72 
911T which was the base model with iron cylinders. During a PCA sponsored 
dinner out of town we convoyed by Interstate 55 to have dinner about 40 
miles away. We all did 90-100 mph and my car began to seriously overheat 
after about 20 miles.  It had the dry sump cooling system but not a remote 
oil cooler.  Now, the engine had 90,000 miles on it at that time but the car 
was not able for sustained high speed runs in stock condition.  Later when I 
had the engine rebuilt ($6,800 in 1985) I had the recommended Porsche 
aftermarket oil cooler installed in the right front fender and that seemed 
to resolve the overheating problems at highway speeds.  The moral of the 
story is that the 911 fan did not cool the engine enough to overcome high 
load conditions. 911 flat sixes with iron cylinders do overheat unless there 
is additional cooling. Many improvements in aluminum cylinder technology 
such as nikasil plating were vital to exceeding 3.0 liters without 
overheating.  There are a number of factors but the fan is not the 
determinant. Yet, I'd think that  a 911 fan would cool my Corvairs o.k.
Crawford