Quote:

Quote:

Chasing higher water flow does not seem to do much for idle cooling, based on the tests I did. It is all about airflow at idle. That is why they go to the 1.3 pulley ratio for AC compared to the .95 for non-AC, to run the fan faster.



Funny, tests I did showed the exact opposite result. My little 2.5L 87 daytona would heat up at idle. Not excessively, but the temps would rise from the 1/4 mark to the 1/2 mark at idle. Bring the rpms up from idle to around 1500-2000 and temps would drop right back down to 1/4. And that's on a car with an electric fan. Electric fan would only kick in at the 3/4 mark on the temp gauge. So all increasing engine rpms did was increase the engine water pump speed. So even with the extra heat generated at 2000rpm, with the water pump spinning faster, the cooling system was still able to dissapate the heat better than at idle. Water pump flow rate DOES make a difference. Either you need to spin the pump faster or get a pump that flows more at a given rpm, or do both.



Yes but the coolant in the radiator was cool enough to cool the engine- in this situation the coolant in the rad. is to hot and once cycled through it gets hotter and he does not have enough air flow to cool it enough. Then once moving the speed of the car will force air through.