Cadillac's and Packards were using thermostat's as far back as 1919. The cars back then had hugh radiators with plenty of coolant capacity, plus they never ran very hard, but a lot of them still over heated due to poor design. My uncles 1921 Cole has two thermostats, one for each bank of 4 cylinders (V8).

In all my years of racing cars and being around cars, they always cool better with a thermostat or restrictor plate. I can't argue with what I have seen and done, and I tried a lot of stuff drag racing for 15 years.

As my 1920 Automotive Engineering Text books says, " all liquid cooled engines are in fact, air cooled" . It all comes back to how well the radiator can get rid of the waisted engine heat.

As far as high volume pumps for race engines, they move a lot of water to a radiator designed to handle it. Dad's 478 ci Pontiac block is half filled with concrete, it doesn't overheat due to properly sizes cooling system and well tuned engine. It uses half the water of a stock system, and yes it has a 180 thermostat and a aluminum 2 core radiator. It can set in traffic and idle for hours or be driven on the road for hours, we have done both.

Joe

1937 Chevrolet Inline-powered Streetrod