Castor oil is the best lubricant there is. It just does what it's paid to do and nothing more. It's a filthy mess inside of the engine but when your only objective for the day is to take the checkered flag then that's what you run.
Klotz, Blendzall, and a few other lesser known entities have built their racing reputations on this stuff. When you have to be first, burn the bean!