Restrictor washer instead of t-stat

[Old Henry]

Guys, (and gals if you're out there) apply the law of thermodynamics and this is the truth of the matter:

The only difference between water moving through the engine slower or faster will be the temperature of the water going into the bottom of the engine compared to the temperature of the water coming out the top. If the water's moving slowly such that it stays in the engine block and radiator longer, then the water going into the bottom of the engine will be much colder than the water coming out the top because the water in the radiator has had more time to cool while, at the same time, the water in the engine has had longer to heat up. That's all. That average temperature of the water in the middle of the engine is going to be the same regardless of the speed that the water is moving through the block. If the water is moving faster and spends less time in the radiator and engine block, the whole water temperature in the block will be more even because the water coming in the bottom will be warmer because it hasn't spent so much time in the radiator while, at the same time, the water coming out of the top of the engine block will be cooler because it hasn't spent so much time in the engine. But, the average temperature of the water in the middle of the engine block will be the same as moving the water slower. That's the only difference in moving water faster or slower is how evenly the temperature in the engine block is, not how hot or cold it is overall. So, decide how even you want the temperature of your engine to be and move your water accordingly.

The overall temperature of the engine block is not affected by the speed that the water moves through it. The only way to transfer more heat to the air through the radiator is to improve the transfer of heat from the engine block to the water by eliminating corosion that inhibits that, and, likewise, eliminate such corrosion from the radiator tubes. Then, ultimately, to really cool more, you've got to just plain have a bigger radiator and/or move more air through the radiator!