We just run water in the block & heads in the all iron SBC, and drain it when we get home. As far as I know NHRA does not allow anything but water, no anti freeze.
Because we have to run block filler in the all iron Hemi for cylinder support, of course no water, but just air cool the heads. Again both motors run alky.
Have run 225° head temp in the SBC, at the turn off, with no problems. Alky likes higher head temps, it burns better. Gasoline likes cooler temps, I've seen gas Comp racers use cooler machines, between rounds.
Talking about cooling, the NHRA Top Alky racers discovered cooling the fuel with small freezers in the trailer, down as low as 30 something. NHRA made a rule to no lower than 50°, checked in the staging lanes or after the finish line. The idea is by running cold alky it makes the air in the heads more dense. Fools the motor thinking it has cooler weather conditions.
I have tried cooling my alky in a ice cooler and over night it will get to 45°, however by the time I can put the cool fuel in the tank and by the time we run, it just is too inconsistant temp wise. I just cool the fuel when it's over 100° air temp, but I do cover the fuel tank with one of those windshield sun shades in the staging lanes and remove before we fire it up.
I hope this info helps.
Jon
