… after sitting from 8pm to 6am in the crankcase 

typical temperatures here at the moment High roughly 36, low 20

So wondering.. park the 84 in the garage at 8pm with oil & water temperature at 200

Stand alone garage of course unheated 

at 8pm temperature about 28-30

at 6am about 20 outside 

im convinced the temperature of the oil is significantly above the outside temperature of 20

the garage, I checked, was 28

Im thinking the crankcase is relatively well protected and the oil - could it be as warm as say 60 ?

Must take a fair amount of time in a windless environment for the crankcase & oil to cool  

any fluid dynamics engineers out there ?

just wondering 

I just moved this to the correct forum category and fixed an issue with the title.

I'm not an engineer of any sort so can't speak with authority on the topic, but from experience can maybe shed a little light.

Fluid temperatures are going to settle down to the ambient surrounding temperature whatever that may be.  How long it takes is somewhat dependent on the temperature difference.  Radiant heat from the block will slow things down a bit at first but as it cools off everything around it will begin to cool off quicker.  The radiator, because of its function as a heat ex-changer, will probably cool off the quickest.  The oil pan is rather exposed hanging below the engine so it is going to cool down fairly quickly based on its location closest to the ground, or in your case the garage floor. 

My guess would be that both the coolant and oil temps are going to be pretty close to the air temp in the garage after sitting overnight.  A quick check with an infrared temperature device would confirm that.  You already know the air temperature in the garage so just for fun take a temperature reading of the garage floor under the car.  Then get readings from the radiator, the block and the oil pan.  I think you'll be surprised that they all are going to be pretty close to the same temperature.

Jim Olson

 
"The Toys"...!!!  Save the Wave! 

 Where I've been in a Corvette...!!!

I am Very much in agreement with Mr. Norsky. The theory of relativity is a factor. Unless moved upon by another force, Heat, or Cold, a body at rest tends to stay at its temperature. So..Even a fire that has  gone out will go to and remain at ambient temperature.