The A2A Simulations Community

A tank engine must have an active cooling system with fans blowing at the radiator(s). Airplanes can rely on airflow of airplane moving where as tanks cannot: they're too slow and occasionally stop leaving the engine running. Airplane cannot stop in mid flight without stalling. And they're fast.

The Merlin may be the same (minus a supercharger since a supercharger isn't needed for tanks that operate near sea level and most usable ground on this planet is within few kilometers of sea level, anything higher is usually too mountainey to be traveled through in a tank), but the cooling system is dramatically different. Not even all planes are identical. For example P-51 also has a Merlin engine (it's a Packard Merlin instead of Rolls-Royce Merlin but still the same basic construction) but P-51 has no overheating problems even on the ground. Not even when running at high power... stationary... on the ground. Still, basically it's the same engine (but with a dual-stage supercharger instead of a single-stage), it's just that the radiator is placed behind the propeller and in the propwash. The propeller functions as a cooling fan. (This is not the case for Spitfire with a wing-mounted radiator.)