Warm Up Times of Radial Engines.

[drewpee]

I don' know about aircraft engines but air cooled motorcycle engines warm up quicker than liquid cooled. Air cooled only have the sleeves and cooling fins to heat. With liquid cooled you have twice the amount of metal in the block and heads. Then there's the coolant and radiator reservoir. Ride a liquid cooled bike hard to soon and you get unnecessary wear and stress.