Additional engine cooling idea?

[mejulihn]

I recently read a suggestion on a 912 website about wiring the heater fan in the engine compartment to a separate switch so that it can be operated independently without opening the heat flapper valves via the heater control lever on the tunnel. Theoretically this would vent additional engine heat from the heat exchangers to the outside and aid in engine cooling. Sounds plausible, but is it worth the effort?

[neilca]

No. This heat is on the way out via the exhaust system anyway. This idea probably came from a liquid cool guy. It is well known in British sports car circles that additional cooling can come from using the heater core as a radiator. Doesn't translate to air cool. Best bet is to cool the oil.
Good luck,
neil

[michel richard]

Actually, this idea probably comes from what was done on some of the 80's 911s, where a similar system was installed. The idea, I believe, is that if you cool the exhaust headers, you will indirectly cool the cylinder heads (either more heat will travel from the heads to the headers, if the latter are cooler, or less heat will travel from the header to the heads). The effect would be much smaller than turning the heater on in a liquid cooled car, but it might still make a small difference.

I would suggest that if you like tinkering, you might be able to make a small improvement to your car.

Cheers.

[roadtrp204]

The designers of the engine already incorporated that idea. There is two outlets on either side of the cooling fan housing. These are constantly blowing cool air through the heat exchangers that exits from beneath the dome cap on the flapper boxes.

In the outlet of the electric fan there is a flap that closes to keep the forced air from excaping through the fan.

In the heating system, the electric fan is only to boost the air flow while engine rpms are low.

An idea that could be of some help is to put the fan on a timed relay that would let the it run for a few minutes after the car has been shut off. This would help dissipate some of the heat that builds up when the engine is shut down. Just a thought
Chris