1960 Poly 318 Temperature

[Kapt]

What's the official word on the temperature these engines are supposed to run at? I've heard everything from 180 to 205, but nothing official. Here's why I ask

I have a 60 Dart, 318 Poly three speed automatic. The water pump was replaced last year. Also last year the heads were off and rebuilt. The water jackets do not seem to be plugged. With the cap off and the motor running there is good flow. I had a three row radiator in it and just this week upgraded to a 26 inch core four row Champion aluminum radiator. It has a 180 temp thermostat in it that has been changed a few times now. I'm positive it is a good one. The timing is set at 10 btdc. The car runs 180 down hill and through town. Doesn't seem to want to get hot while at idle or low speed. When I go home and back up the hill, it runs about 190, and hits 200 in my driveway. It did this exact same thing with the three row, it did the exact same thing with the old water pump, and it did it before the heads were rebuilt. It has a mechanical temperature gauge in it make by Equus. I've had several of these in the car because like an idiot, I keep breaking the sender if I have to pull it for some reason. Anyway, there is literally no reason it should heat up. Any ideas? Should I change the thermostat to a 190 where it wants to run at under load maybe?

 

[Xenon]

Now try changing the thermostat to a 195..
A 180 degree 'stat does not mean water will only get up to 180...
It means it full opens at 180... By fully opening later the coolant
is in radiator longer so gets cooler...

 

[Kapt]

I was just talking to an engine builder friend of mine. He said it's old. Still runs. Prolly worn (it is). If it's not puking (it isn't), 200 isn't going to hurt anything. Enjoy it and don't stress.

 

[bronze turbine]

If you check with parts suppliers, they all say that 195 is the recommended temp for cars of our era. Originally these cars came with 180 but I think some time around 1970 the factory starting raising the temp for emissions reasons and finally settled on 195. That said, I don't think anything under 210 is anything to be concerned about.

 

[Big_John]

If your car is running 200 degrees with a 180 degree thermostat, leave it alone. It's all good.

 

[CBODY67]

For a good source of factory literature on 1965 and back Chrysler cars, www.jholst.net is it. www.MyMopar.com has also added some of that content to their website. On jholst, you can also find the parts books plus service information. The website is oriented toward 300 Letter Cars, but also has normal cars in it too.

When those cars were new, with even the factory-supplied factory a/c radiators, they did NOT overheat UNLESS something was wrong. Period. Which makes, from my experiences and those of others with those cars back then, the 4-core overkill over the factory 3-row factory a/c 26" radiator. FWIW

Expecting the coolant temps to always be at 180 degrees F under or after any load situation might be a bit unrealistic. BUT do ensure that your fan clutch (if equipped) is functioning as designed and to do a full cleaning of the block's coolant passages. Gunk settles out in the low places, which will be the rear of the block. Only way to really do that is to remove the block's freeze plugs and "get wet" (with the car on a lift). I suspect you'll find some accumulation back there.

In reality, the real key thing is that the engine does cool back down after your load situation and stays there in other normal driving. Remember, too, that the "boil-over" temp on a pressurized cooling system (for the psi rating of the radiator cap you probably have) is close to 260 degrees F. ATF starts to degrade at about 270 degrees F with motor oil a bit hotter than that. Even at 220 degrees F, there is still a good bit of "cushion".

If you might get caught in city traffic, remember to keep a space between your car and the car in front of you. So the radiator can see cooler air flow as a result. Plus that the yoke seal on the front underside of the hood is in place and not missing.

Our '72 Newport 400-2 was OEM-spec'd with a 185 degree thermostat from the factory. But finding that temp in replacement or the aftermarket was impossible. Chrysler later followed others into the 195 degree area, by observation.

Keep up the maintenance and enjoy the car,
CBODY67

If you don't already have one, an infra-red non-contact "heat gun" has become pretty inexpensive in the last decade or so. It can make a great diag tool for heating situations on cars! Harbor Freight (or similar) can be a good source for one.

 

[CBODY67]

If you check with parts suppliers, they all say that 195 is the recommended temp for cars of our era. Originally these cars came with 180 but I think some time around 1970 the factory starting raising the temp for emissions reasons and finally settled on 195. That said, I don't think anything under 210 is anything to be concerned about.

They probably recommend the 195 as that's what THEY grew up with AND also what they have in stock, by observation.

 

[Davea Lux]

180 degrees was the factory thermostat back when these cars were new. It is normal for the temperature to rise when putting the engine under load on a hill. The temp will also rise in low speed traffic due to decreasing air flow thru the radiator. The numbers you are reporting are normal. Drive and enjoy the car.

Dave

 

[bluefury361]

200 isn't overheating....... A 180 or 195 thermostat will work. Unless you have a overflow tank it will puke out coolant until it's happy. It will seek it's own coolant level. Topped off isn't always a good thing.

 

[Kapt]

Thank you for the replies. I'm going to do as advised and just enjoy the car