I use a rad/fan from a Pontiac Firefly. It's more than enough for an alcohol engine.

If you cannot build heat in an alcohol engine the carburetor is not setup properly do so. Lean the idle out, you will use less methanol, lower fumes, more temperature and cleaner oil.

quote:

Originally posted by markemark:
What temp thermostat are you using with the 4 holes drilled in it??

180*

quote:

Originally posted by RyanNorton1:
If you cannot build heat in an alcohol engine the carburetor is not setup properly do so. Lean the idle out, you will use less methanol, lower fumes, more temperature and cleaner oil.

Agree with this, BUT you can experience a lean stumble at the hit, especially if the air gets significantly better, (like if you started out in a day or afternoon race, and make it to the later night-time rounds). Happened to me this year, fortunately my opponent went red, or I was done. In this situation, you better think about going 1/8-1/4 turn richer on your idle mixture screws. I did, and it cured the issue for the next round.
Bottom line, that is one more thing you really don't want to have to think about in the heat of battle. I am all for a leaner, clean idle on alky, but not to the extreme that it can cost you a round, or a paycheck.