Hi all,

Temperatures here will be 100 degrees this weekend. I'm planning a drive tomorrow, so I would like to ask you guys for recommendations for keeping the engine from getting too hot. i.e. Not improvements to make for the future (I have a plan for that already), but just tips and suggestions to improve things for tomorrow.

1. My thought is as long as I'm willing to pull over at a rest area whenever the temperatures get high, and turn the car off and let it rest for 20 minutes or so, I'm thinking I should be fine. Am I correct in saying that or is 20 minutes not nearly enough for getting temps down an appreciable amount?

2. What would you say is the ideal RPM for max cooling? On the highways here, I can sometimes get as low as 2400 RPM in 5th gear while driving the speed limit. I suspect that 2400 RPM is too low for optimum fan cooling - although it also generates less heat than a higher RPM, so the question is where is the tradeoff optimal point of RPM.

Thanks in advance!

3-3.5K. If you are falling below 3k, shift to 4th. Unless you are going downhill.
I wouldn’t stop and pull over. Car will heat soak and may be hard to start.

It is a 2 Liter with Webers - I forgot to mention that.

@mepstein

I forgot to mention, one major thing I'm worried about is traffic getting very heavy which means I could be stuck in stop and go traffic for 30 minutes or so. I'm thinking in this case pulling over is the right solution. Do you agree?

Tough call. It will be easier to decide if you have a temp gauge. My advice, if you can, leave as early as possible and bring a chest of cold water to keep yourself cool and hydrated and sunscreen.

I drive at the speed limit instead of +10 or +15 ovet and sometimes a little less, temp drops back.Highest temps occur in stop/go traffic.

I have a good amount of experience driving in 100+ temps. My car (1911 cc w/Webers) runs normal temps (oil 220F heads 325-350F) up to about 65mph cruises. Above 65 or in the mountains the head temp creeps up. Once the heads exceed 350 I keep the revs around 4000 and that keeps them from exceeding 375. On prolonged periods above 4000 the oil temp starts to creep up. At that point I will slow down a bit or be sure to lower rpm on the flats or downhills to lower oil temp without raising head temp. Having both head and oil temp gauges is critical IMO.

Remember, our cars are Air Cooled. Keep moving and keep the rpms in the 3 - 3.5 k range, and you will be fine.
Stopping for 20 min in 100+ temps will not do much to cool things off. (And it might cause restart problems. ) You will need more than an hour for any significant drop.
30 min of stop and go is no big deal. Trust me. It will bother us humans more than it does the car.


BTW - Check your Tires and Happy Motoring.

if it gets a little warm inside the cabin

Click to view attachment

For future, the Floor Pan Air Deflectors.....helps pull more are through the engine compartment at speed. Best, Mark

The challenge on the New England corridor is stop and go traffic. I drive to Maine a lot to see my daughter. It could take 8 hours, it could take 12. Driving south to visit my son in NC, it's always 8 hours.