On the shelf I have a Dirt-Track Model radiator that was fitted to my 1929 bitsa sprint bike, and it is TINY. It was OK for a quarter-mile sprint, marginal for a kilometre event, and a prolonged wait at the startline for other riders, with the engine running, was out of the question as it would rapidly come to the boil.
I don’t know what fuel they ran in Speedway/Dirt-Track back in the late 1920’s, but IF it was Methanol, letting the engine run much cooler, it would have been no problem.
Brian
