I had these thoughts, too. This is what I decided;
If you have an accurate means of measuring temperature like an IR Temp gun, you could give it a try to see if it's worth the effort for you, but unless you're operating at low speed in the Mojave desert at high noon, or have no shroud or fins, you probably don't want to bother. Overheating is a problem that presents itself as obvious. Less obvious is the problem of overcooling. Running an engine too cold can be fatal, too.
So to do it properly, you'd have to determine the ideal operating range, likely measured at the cylinder head, and then rig up a temporary system. Back up to OpTemp as measured at the head, and then measure the coolant temp. Now set up the system to thermostatically control the liquid system (like a car) to keep the temperature within the acceptable range. Test, re-test, re-re-test, then set it all up for good, and test some more. A water pump driven off the engine will rob ponies. An electrical pump will take a fair amount of current, let's not forget the radiator cooling fan. Better install an alternator. Which adds weight. Speaking of weight, add in the weight of a radiator, all tubing and fittings, thermostat equipment, and the weight of the coolant itself. All this for an engine with a pre-engineered cooling system built in (for normal operating conditions). If you can pull it off, I'd enjoy seeing it. Don't think it's worth it, though.
If I peed out your campfire, sorry. You asked! Cheers!