Model As were not built to run that hot. You run up to 212, you run the risk of hurting the motor. Cylinder wall oil flash over, metal parts not spec'd to hotter temps, etc.
There is not a lot of difference engineering wise between today's motors at 15psi/249F and the Model A at 0psi/212. What has changed since the Model A era is the oil. Today's oils, driven by the desired increased temperatures, have a "flatter" viscosity curve - especially so for so called "synthetic oil."
A pressurized system does not cool better and antifreeze does not cool better than water. They only allow you to run hotter before boiling.
A pressurized system DOES cool better. That Delta T thing I mentioned. More heat can be transferred, or potentially a smaller radiator required for the same heat transfer.
Now heat transfer from the motor TO the coolant will be retarded a bit with increased coolant temperature - that delta T thing again. So your motor will run EVEN HOTTER than the increased temperature of the coolant might suggest. But again - those oils.
As to the efficacy of pressurizing, it has plus and minus. Plus on efficiency, life of the motor (did I mention that?) and conservation of coolant. Minus on lubrication.
Plus - my comment on "
Thats Just Stupid." What is stupid is making a statement like that without consideration of listener.
I'm a kind of a "keep it original" sort of guy. I get my jollies from the originality of the Model A car and its "uniqueness." I hold it as a kind of a comparison and look back to see how far we've come - and a reminder of how brutal and hard it really was with 500 mile oil changes and maybe 20K miles tops on a set of bias ply tires. (I remember myself how we thought tires were SOOO improved because then they could be driven 40K maybe 45K miles. And you changed your shocks at every other tire change - 80K.)
Others have a different set of standards. They like to drive the car for PLEASURE - and they do things like hydraulic brakes, shortening the pitman arm, speed upgrades, overdrives, and a whole parcel of so called "improvements" to the car. When they're done is it still a Model A?
I make a living currently restoring old houses. Many times a client consults with me about this improvement or that improvement. One of my standard comments to these queries are "Yunno they're only original once." And another is "You can upgrade the colonial charm right out of this house if you're not careful." Part of what makes historic houses historic is the fact that they're not like modern houses: winder staircases, short doors, wavy glass, and low ceilings. Remove all this and you remove the charm - in my estimation.
But there is the engineering side of me who appreciates running water, toilets that work, cellars that are full height and dry, and energy efficiency.
So like the Model A - I see both sides here too.
And I don't blurt out - "
That's just stupid." Because for the hearer - it might not be.
Joe K