In order not to clog the current 'ideal P-47' thread, maybe it would be okay to start a new thread that would cover the most interesting Anglo-American engines and their applications, namely Merlin and R-2800. It can be argued that turbo R-2800 was a two-stage engine, since the turbocharger was also a stage in compressor system. For starters, here is the table with R-2800-10, the engine used in Hellcat, along with Merlin Mustang's engines. The R-2800-8 was used in Corsair, and was basically the same engine. Some sheets, eg. the one found at William's site, list the military power of the -8 and -10 engines as being 1650 HP at 21000 ft. Any information that might clear the 1500 ft discrepancy is welcomed. The 1800 HP at 18500 ft is a war emergency power value (max WER was at 1950-2000 HP at a bit lower altitude), not military power. Power values are without ram. Please open the pic separately for high resolution.