How hot is too hot

[Guest Californiagates]

When your engine is idling on a 1929 Desoto six how hot is too hot do they run hot,just got running not sure where it should run

[Guest 60electra225]

How do you know it is hot ? From the gauge ? Would suggest you get an infrared thermometer to check actual temp. Probably should be around 140 - 150 when up to temp.

[R Walling]

How hot is too hot

Theroretical question,

I have often wondered how the boiling point of water relates to an engine.

Are the clearences machined for an engine to operate between 150 and 220? If so what if you wished to opeate at , say 300 degrees.

Could you simply use a different coolent, or would you have to machine the clearences and use a different oil for that temp?

Edited October 5, 2011 by Roger Walling (see edit history)

[jrbartlett]

If you post this under the Technical section, you'll get a lot of advice on what to check -- such as ensuring the radiator and engine block are clean, checking the timing, making sure the intake hose doesn't pinch closed, etc. If your car is running hot, I'll pass along a tip from our experience with a '29 DeSoto 6 during the 1960s. The water pump pushed the water through the radiator too fast. We fixed it by drilling a half-inch hole in a round piece of wood and putting it into a radiator hose. That solved an overheating problem. I don't know why we didn't just install a thermostat. Would probable work just as well.

I also had an oldtimer tell me that optimal running temperature on a '35 Auburn was 100 degrees plus the air temperature, plus another 10 degrees if the car was super=charged. Maybe there's a similar rule of thumb for Chrysler products.

[Guest Californiagates]

You guys are great I will give that a try thank's Mitch

[Guest]

My car originally came with a 140 degree stat. In the sixties when GM started puting 180 stats in cars I changed mine to a hotter one. Same again in the seventies. For 35 years now I have been running all year around with a 195 degree stat. I believe that the car runs better and gets marginally better gas mileage. Of course this is only limited experience since I have only driven it 399,600 miles in the last 52 years.

[lozrocks]

All water cooled petrol engine cars pre 1960s should run at 185 degrees Fahrenheit. Now there is a whole heap of formula to consider taking into account lowest operating temperatures and highest operating temperatures and power bands and all that crap. But the reality comes down to peak efficiency for all internal combustion engines of that era being 185 degrees. All cars will run slightly hotter at idle and slightly hotter with heavy loads.

Side valve Chrysler engines don't like running above 200 degrees; they tend to cook piston 5.

The other trap with pre 1930's Chrysler, Dodge, Desoto is the temperature gauges are notoriously inaccurate and generally read low.

[jrbartlett]

A reminder. Before you start trying things, you need to determine what is wrong in the first place. You didn't provide much information on the condition of the car, etc., that would enable us to provide suggestions in response to problems. So I think you must start by measuring the actual temperature (as already suggested) to determine whether you really are running hot. Then, what is the actual condition of your cooling system components?

[Guest Californiagates]

Hi James I have a re core radiator flushed out block,radiator boiled over removed old 140 thermostat ran engine at idle for 10 min ran 200 degrees drove car stayed at 150 I'll try to install a 185 degree thermostat one post said to slow the water down to let radiator cool the water thank's for the info Mitch.

[Guest Californiagates]

Reid that is a beautiful car.how reliable is a 1929 Desoto just got it running wondering what to expect I have no idea thank's Mitch

[Guest]

Mitch

I would think a 29 Desoto would be as reliable as my Pontiac has been or perhaps better. Your car was a higher class car than mine. Your engine was used almost the same up until the 60's and still is used industrially. My engine was discontinued in 1932 and totally redesigned when reintroduced in 1935. Drive it and enjoy it.

[Guest De Soto Frank]

With a clear radiator, clean block, good water distributer tube, proper timing, they should run at whatever the thermostat temperature is.

160 * F was considered the max when using alcohol-based anti-freezes.

With Permanent-type antifreezes (ethylene-glycol), running temps of 180 * were possible.

Modern cars can run more efficiently at even higher temps, but I do not like to see old iron running warmer than 180-185 * F.

By the same token, they should not run any cooler than 150-160 * F... if the cooling system is working that well, great , but any cooler is too cool for efficient operation and will contribute to crankcase dilution and formation of sludge in the crankcase.

Suggest you fit a modern, decent quality mechanical-type temp gauge while you getting the car back on the road, and once you are certain things are running in good order, see about going back to the original gauge.

You can test a thermostat using a pan of water on the stove-top, with a $10 digital kitchen thermometer... if the stat does not open within 5 * F of the temp stamped on it, it is probably defective. A 140* stat should be wide-open by 150 * F.

Chrysler Products were always well-engineered cars... put in good condition and driven repspectfully, they are quite durable.

[Guest Californiagates]

Thank's for the reply I installed a 160 thermostat stays 160 driving, at idle after a few minutes it rises up 190 200.does anybody know how to check the timing ?