Most of us who run in the altered classes re-circulate engine water through a on board water tank for that very reason.
On my car I have a 25 gallon tank that engine water goes into before re-entering the radiator. Water enters into the front of the intake manifold water passages and exits out the rear into the tank.
The engine never reaches 190 degrees even on 25% nitro.
I run no fan and the grills are covered. I use a belt driven water pump simillar to the ones Speedway Motors sell.
I preheat the water tank and my oil tank to get near operating temps before each run.
I believe Stainless does the same on his motorcycles with a Bic lighter..........
Bob