Block heater ducts on early 911's for more engine cooling

[Artfrombama]

My 73 oil temps border 250f on long drives when ambient is around 90f. Everything is in good tune and I don't have vacuum leaks/retarded timing/etc.
Was thinking of capping the heater ducts either underneath or underhood in the Summer months to force more air around the motor and through the oil cooler.
Has anyone done this with favorable results?

[skinnerd]

Not sure your temps should be that high on a normal healthy engine. Get your temp gauge checked for accuracy, etc. Has your engine always run this hot? Do you have an aux cooler in the passenger side front wheel well? Others will climb in I'm sure, but something sounds amiss.

[john walker's workshop]

The airflow through the heat exchangers cools them. Take that away and they radiate more heat. Try a larger SC crank pulley for faster fan speed. Even faster with a later fan with a smaller pulley.

[Jack Stands]

I’d think you’d have to switch to headers to increase cooling air flow under the engine if you block off the heater ducts. However, you shouldn’t be running that hot with a 2.4 if running correctly - maybe verify the gauge is correct (the boiling water test). Have you considered a front oil cooler if you want to cool the engine down?

[ClickClickBoom]

The temp sender is on your crankcase, oil is a heat transfer fluid(and lubricant), if it’s too hot, you need more heat rejection surfaces, ie oil coolers. The thermostat is also a wear item, insure it opens completely. If it’s not opening completely it doesn’t matter how many coolers you have or don’t have.

[BK911]

Mouse nest on top of cylinders!
Peek through the fan and see if any junk is in there.

[RedCoupe]

Originally Posted by BK911

Mouse nest on top of cylinders!
Peek through the fan and see if any junk is in there.

+1 This is really common. Also, a nest can block air flow to the engine-mounted oil cooler.