@Yellowrose, your concept about the t-stat setting the minimum temperature is basically correct. But your numbers don't work out if the shop manual is correct, and I think you are wrong to dismiss it. The thermostat openings have a plus minus of 5 degrees to crack open enough to get a feeler gage in. Full open is around 20 degrees hotter - plus minus some. Surely you're not saying those shop manual specs are incorrect.
This is what my post was referring to.
Also when tech goes out of their way to say that the 1968 Chrysler system does not pressurize due to coolant expansion, then someone says that cooling systems pressurize due to liquid expansion; that person either didn't read the explanation, or doesn't believe Chrysler knew how their own system worked.
Now, why run a hotter rather than a cooler engine?
On a low compression street setup I would give two reason:
1. To get rid of the condensate in the engine, especially the oil.
2. To more completely vaporize the gasoline.
Now that second can be argued about. I don't have numbers or test or any of that. But this is what Shrinker was always writing about and I buy it. When we set up relatively low compression situations we need to get enough heat in the chamber so light and medium portion of the fuel vaporizes and distributes evenly before spark.
On some engines this isn't going to apply because the heads, piston and cam are doing the work. So on some engines more heat could hurt. I get that.
