Talk:Macchi M.39

Engine confusion
In 'Design and development' the Fiat AS.2 is stated to power both the trainer and the racing aircraft, one at 600 hp and the other at 800 hp which seemed odd. I believe the 600 hp engine used in the trainer was the Fiat A.22, this is supported by the Italian article on that engine. I don't have the source used for this section so can't change it. Nimbus (Cumulus nimbus floats by)  08:30, 26 July 2022 (UTC)
 * It's not impossible - and could represent tuning the racing engine to it's limits - consider the power delivered by Napier Lions in racing aircraft compared to normal use.Nigel Ish (talk) 18:29, 26 July 2022 (UTC)
 * Hi Nimubs227, this part of the sentence hasn't a source given anyway - so I was bold and changed this now. --Cyfal (talk) 19:04, 26 July 2022 (UTC)
 * And I changed it back again because the paragraph was sourced - and Donald does in fact say that the first example had an AS.2 engine rated at 600 hp, with the racing aircraft having their AS.2 boosted to 800 hp.Nigel Ish (talk) 19:10, 26 July 2022 (UTC)
 * The Italian M.39 article has this passage (Google translated) Satisfied with the preliminary projects, the ministry issued a supply order for five units, two for the training of pilots, characterized by a wingspan of 10.23 m and by the different propeller group, a Fiat A.22 with 550/600 HP. combined with a two-blade wooden propeller, identified with the military serial number M.M.72 and 73, and the other three, the M.M.74, 75 and 76, in stroke configuration, equipped with the AS.2 motor equipped with a two-blade metal propeller and with opening wing reduced to 9.26 m
 * It is cited to an Italian book. It's not explained but the trainer propeller would have been fine pitch for better take off and go-around performance and the racer propeller would have been a very coarse pitch for maximum airspeed.
 * I've ordered a copy of The Schneider Trophy Story by Edward Eves, I used one from a library for another article, it was fairly comprehensive. Nimbus (Cumulus nimbus floats by)  08:25, 27 July 2022 (UTC)
 * I have the book now. At the first mention of the M.39 the wording is The two trainers were powered by 600 hp engines, presumably the production A.22. Not exactly concrete evidence! Nimbus (Cumulus nimbus floats by)  10:45, 2 August 2022 (UTC)
 * Thank you for your effort. That is indeed not enough to support the A.22 claim. --Cyfal (talk) 19:56, 2 August 2022 (UTC)