Every day I drive 30 miles to work. Every freeway in Fort Worth is under construction that'll last another 2 years. Now the air temperature is hitting 102.

My speed is 50 mph most of the time. Will the motor run cooler by shifting up a gear with rpm at 2200 and depend on outside air flow over the motor?? Or will the fan provide better cooling than outside air flow by downshifting to maintain 3000 rpm?

Anyone who knows or can test this who has a cyl temp gauge?
4 cyl 2.0

Thanks all

Heat is based on load and RPM. Try to keep the motor closer to 3000 RPM and you are close to the "fat part of the curve" for cooling. The best CHT for the money is the Micro 1000 sold at Aircraft Spruce.

I experimented with this years ago in another air cooled vehicle where I have both oil temp and dual cylinder head temp.

Relatively speaking with respect to gear choice:

- In 4th gear, the cylinder head temp is higher and the oil temp is lower.

- In 3rd gear, the cylinder head temp is lower and the oil temp is higher.

All depends on what you want. Do you know what your head temps are at? Is it worth possibly overheating the oil? Any pinging?

One of the worst "modifications" made is an 009 distributor. If you have vacuum available, use a vacuum advance distributor which will keep your engine cooler at steady state speeds.

Since you bring it up...
What if you have a '76 2.0 where the vacuum advance is intentionally left unconnected? I have an "011"

Keep in mind that the mid 70's were a bizarre era where vehicle manufacturers were trying to keep emissions down to meet federal standards. Porsche was intentionally raising operating temperatures to meet these standards. It wasn't just '76 that had the advance lines intentionally left disconnected. Look at '74 where the retard was connected and the advance left to atmosphere!

Roughly '75-'77 were the thermal reactor and 5-blade fan years for 911. Just an ugly time IMHO.

So back to your '76... If the advance line isn't connected, connect it! Follow Jeff Bowlsby's drawing for a '74 2.0. This will help your engine run cooler.

Living in Phoenix I watch my oil and cylinder head temps and have noticed that the heads are cooler and oil is hotter at high RPM, and vice versa as long as I'm not really loading the engine. My rule of thumb going thru the mountains is if I can't accelerate in a particular gear I downshift. Of course I'm driving a barely-more-than-stock 1.7 with carbs.

Not having any problem. Pinging or otherwise. Car runs good but worried about 105 degrees today and a hot summer ahead. All I want is a long life motor

Keeping the 3000rpms up.