1009 hot weather operation

[rsh4364]

Well there you go, your reading the (radiator), not the (engine). And if your getting 190° at that point it must be running HOT!! Think about it, if the coolant (entering), the engine is already 190°. Then what is it leaving the engine? The only way to get an honest, accurate reading of the (total temperature) of any engine is to take that reading just upstream of the thermostat. Remember your thermostat is what controls the operating temperature of the engine.

Until the thermo opens there is no flow thru radiator,coolant just circulates around block,thats why we have that bypass hose also.

 

[welpro222]

I have a temp sensor installed in my crossover right before the thermostat. I have a 180 robertshow thermostat, and it reads 185 most of the time, then climbs to 190-200 on any hills. I've had it hit 220 on long hills. I think it reads hotter in the crossover then having a sensor in the drivers head?

 

[Drock]

Until the thermo opens there is no flow thru radiator,coolant just circulates around block,thats why we have that bypass hose also.

That's correct, but your reading at the water pump is contaminated by the cooler water sitting in the lower radiator hose. And when the thermostat opens the rush of even cooler water at that point. By taking your reading at the thermostat you know exactly what the system is doing. And if the thermostat is functioning properly. This isn't just ah theory of mine . If you pop the hood on any car you'll see that's how factories design there cooling systems.

 

[MarcusOReallyus]

That's correct, but your reading at the water pump is contaminated by the cooler water sitting in the lower radiator hose. And when the thermostat opens the rush of even cooler water at that point.

I was just reading some good info on this on another forum. One of the regulars is a former Ford transmission engineer, and his experience with the temperature difference on a radiator is very interesting:

I've measured extreme temperatures in my capacity as an Automatic Transmission Cooling Engineer at Ford. At VERY cold temperatures, such as -40F, the coolant in the cold side of the radiator didn't rise above about -30F. The coolant going into the radiator was about 200F. The engine thermostat only opens for a very short time before it cools off with -40F coolant coming into the engine. So the coolant in the radiator sits there with -40F air blowing over it. So the ATF goes into the radiator and sees coolant that is not above -30F. Kinda blows the whole heating the ATF myth out of the water, doesn't it? And remember, I measured these temperatures, I'm not just guessing how this works.

And in hot climates we only tested at +95F and above. When I ran trucks (up to the F-550) up 8% grades at max GCVW the temperature drop across the radiator would get down to as little as 15F. The "cold" side of the radiator was still cooler than the ATF. The transmission was also working very hard and generating a ton of heat. The radiator really helped keep the trans temps under control.

So the cold side of the radiator is a lot colder than the hot side, ergo, any mixing of that lower radiator water will make your readings very inaccurate.

 

[rsh4364]

So I don't have a coolant temp. gauge,but I do have a handy thermostat operation verification gauge.LOL

 

[MarcusOReallyus]

So I don't have a coolant temp. gauge,but I do have a handy thermostat operation verification gauge.LOL

 

[cucvrus]

Put multiple temp gauges in / on and have them in a row and monitor the coolant temp at every point thru the multiple temp gauges. I would say about 6 color coded coolant temp gauges would do it for the coolant and 4 for the transmission. Fill up the right side of the dash and both a pillars. And you still have room for pyrometers and transfer case temp and 2 differentials. Cool. Rick you do that you are the race car guy.