Cool/Heat: Engine Running too cool

[wdills]

So last year I discovered that my original 2 row radiator couldn't keep up on a hot day with the AC running. When ambient temp was about 80 degrees or less the car would warm right up to 180 and then stay there. On hot days, 90 or more, the temp would constantly creep up even running 60 mph.

A very brief search revealed that a stock 2 row radiator ain't gonna get it done with AC unless you live in the artic. So I spent the money and had Griffen build me a replacement that has about 3 times the cooling capacity of the original.

Since installing the new radiator the car will never get up to 180 degrees. It warms up to about 165 and stays there regardless of AC on or off or temp outside. My first thought was that I had originally installed a cooler thermostat when I built the car. So I bought a new 180 thermostat and installed it. When I pulled the old one out it turned out to be a 180 degree as well.

Am I missing something here? The thermostat is obviously working because temp is being controlled at 165 degrees. What should I look for? When I installed the new radiator, I didn't do anything regarding the wiring. I don't see how the ground to the engine could have magically changed during the two weeks from the time I removed the original radiator unit I installed the new one.

Any thoughts would be appreciated.

[Mike Sal]

Why not try a 195 t-stat?

[StudeRich]

So what IS the current Temp. there? Maybe 30 Degrees?

UPDATE: I see NC is 22F right now, no wonder!

When it is below 40 or so here, I have to block HALF of my Transtar's Radiator with cardboard to get it to normal Operating Temp. Stat open, 180 Degrees.

[Hallabutt]

I have the same thing with my 1960 wagon. I have two pieces of cardboard, one for winter, and the other for summer. Not and exact science, but it's better then having to worry about overheating.

[345 DeSoto]

Original Tstat not operating properly

[JoeHall]

For many years, I have ran radiators similar to yours, in all Stude Hawks. I use a 195 t-stat, year round. As yours, the temp seldom gets above 180 here on the east coast. Out west in the desert, they will slowly climb to about 100 degrees over whatever the ambient temps are. The main difference between smaller radiators and larger/more efficient ones, is that they climb SLOOOWLY.

The cooler temps will not hurt your motor, and it will greatly reduce summer heat related problems, i.e. vapor lock. It also keeps the firewall cooler, for less heat transfer into the car. If in temps below the 30s, you can always, as mentioned above, put cardboard in front of the radiator. But be careful not to overdo it, and be sure to, "adjust" the cardboard size and position, as temps warm up.

[wdills]

Should have been clear that these temps are not current. They are from last year, July through November. Then I put the car to bed for the winter.

Joe: So you are seeing the same thing I am. Your temp runs 15 degrees cooler that the T-stat. My question is why.

If the thermostat is designed for 180 degrees why doesn't it control at that temp. My only explanation is that the thermostat cracks open at 165 or so and doesn't get fully open until 180. If this is correct then maybe with the oversized radiator I basically end up operating at the point where the thermostat just begins to open. This theory would translate to Joe operating at 180 with a 195 degree t-stat. Is this theory of operation correct or am I missing the boat here?

[Hallabutt]

No expert, but try to answer your question, with a little intuitive guess work. "When the wax melts, it expands significantly and pushes the rod out of the cylinder, opening the valve. If you have read How Thermometers Work and done the experiment with the bottle and the straw, you have seen the same process in action. The wax happens to expand a good bit more because it is changing from a solid to a liquid in addition to expanding from the heat". My guess is that most thermostats are either open or closed. Once the wax melts the thermo. opens completely, if it's working properly, but the wax is unable to re-solidify until the engine cools. I believe that there are some thermostats that will adjust to coolant temperature, but most will not.

[Jeffry Cassel]

We always put a 160 deg thermostat in in the spring and swaped it for a 180 deg thermostat in the fall I always assumed the folks who engineered the engine wanted it to run between 160 and 180 deg. Modern cars run hotter --probably pollution control. 160 to 180 sounds perfect; Why alter it??????

[plee4139]

The temperature gauge on my Sky Hawk always read very low except when I had the car in the Fourth of July parade, and then it climbed and would tend to stall. Last year I had to have the engine and cooling components completely rebuilt due to cooling system failure. There was no thermostat in the car (?) and the gauge was not connected (yet it worked). New there's a six blade fan and correct hoses. The really sad part is that the previously rebuilt engine only had 15k on the clock! The chief mechanic at Slo-Mo Joe's Engine Rebuilders (Our motto: 'You'll get your car back someday") found some thing not done correctly, but could not say for certain how this happened. Thoughts, please.

[345 DeSoto]

Your temperature gauge was connected to other than the correct sending unit, thus sending a false reading, allowing you to believe your engine temperature was MUCH cooler than it actually was. The engine over heated and killed itself. BIG clue...stalling when the gauge started to climb...due to severe over heating. One added benefit to rebuilding my own engine/transmission...I got to see where everything was SUPPOSE to go when reinstalling.

[JoeHall]

The temperature gauge on my Sky Hawk always read very low except when I had the car in the Fourth of July parade, and then it climbed and would tend to stall. Last year I had to have the engine and cooling components completely rebuilt due to cooling system failure. There was no thermostat in the car (?) and the gauge was not connected (yet it worked). New there's a six blade fan and correct hoses. The really sad part is that the previously rebuilt engine only had 15k on the clock! The chief mechanic at Slo-Mo Joe's Engine Rebuilders (Our motto: 'You'll get your car back someday") found some thing not done correctly, but could not say for certain how this happened. Thoughts, please.

When you started another thread several months ago, on the same subject, I do not recall you sharing that you had ran the motor till it overheated and shut down. Even so, that should not have damaged it, as Stude V8s tend to vaporlock and shut around 225 degrees. That sort of protects the motor from itself, by shutdown just before meltdown. I have NEVER used a Stude in a parade, and never will, due to potential overheating. A few years ago, at the Stude IM in South Bend, they had a parade in 80s-90s heat, and many of the Studes stalled, as yours did. So it is perfectly normal for them to do so, under those conditions, with a standard cooling system.

A heavy duty cooling system, which included a 16" pusher fan in front of the radiator, is what I used when daily driving in the desert with Studes, for six years. I had an on/off switch, to use anytime traffic slowed/stopped, and the temp was over 100. I recall sitting at a light in Palm Springs, with the AC blasting, and a temp sign at a bank saying 122 degrees. Studes are capable of operating under those conditions, but not with an OEM type cooling system.

I did gall a piston on a 1964 Wagonaire in the desert once, with only 66,000 miles on it. Bought it from a guy who lived about five miles from me, and drove it home. The thermostat was stuck, and the motor boiled the block dry on the way home. The motor then developed a light tic, so I pulled all the pistons, and found one galled. Replaced that piston, re-ringed the motor, and my then fiance' and I drove that wagon about 50,000 miles, without any further problems with the motor.

[plee4139]

Best explanation yet. Thanks.

[altair]

I once owned an 80s Buick and it had a 185 degree thermostat and I drove that car in -40 temp and it was comfortable and warm, up to 120 stopped in traffic and the engine temperature only moved up slightly. I think the biggest problem is dirty blocks. I have a 259 with a 160 thermostat, as called for in the manual, and it runs right on the numbers. The block was full of crud and I thoroughly cleaned it out. I had the bare block suspended on a chain hoist, removed the plugs used a section of coat hanger and probed the rust and crud and flushed with a garden hose. Don't do this on any cement or you will have rusty cement for ever.

[wdills]

I found the quotes below on the Stant website. It seems my thoughts regarding operation were incorrect. A 180 degree thermostat should begin to open at 180 and be fully open at 195. This means that my two 180 degree thermostats and Joe's 195 degree all operate incorrectly. Could Studebaker have deliberately marked their thermostats different from industry standard? Or is it more likely that modern re-pop Chinese parts are stamped incorrectly for their operating temps?
When does a thermostat start to open?

The thermostat starts to open at the rated temperature, plus or minus 2 degrees (F).
When is a thermostat fully open?

The thermostat is usually fully opened at 15 - 20 degrees (F) above the opening temperature.