Thank you for the prompt reply, Sir.
I was aware some early examples got imported Cyclones, but was under the impression only a small number of these were available. The Gordon/Dexter account is that 1934 production was split between imported Cyclones and M-25s, and that while 1935 production was intended to have M-25s, not enough were available and so M-22s were substituted on some machines. Having looked over the book again, I see I mis-remembered in taking M-22 example as early production.
Everything I have ever seen on the Shvetsov M-22 describes it as a derivative of the Jupiter radial, with the Cyclone derivative being designated Shvetsov M-25.
It was so prompt that a couple of typos creepped in...
288 I-15 fighters were made in 1935... all those I-15s made in 1935 had
M-25 engines (licence "Cyclone")... Hope it's clear now...
The production figures in the 'Red Star' are larger than those you cite: 94 in 1934 (60 Zavod 1, 34 Zavod 39), and 288 in 1935 (273 Zavod 1, 15 Zavod 39), but perhaps there is a typo involved? Or is it possible that 188 received M-22 and 100 received M-25 in the 1935 production run?
It looks that confusion with M-22 engines has been created by V.B. Shavrov (author of the "soviet aviation bible"). Shavrov says (page 522) that "
only some of the earliest I-15 had american made "Cyclones" and that M-25 wasn't available in 1934. M-22 (480 HP) engine was available in large quantities and it was installed on I-15s which were made after those first few. Several hundreds of I-15s with M-22 engines were produced from 1934 to 1936. Planes with M-25 engines were produced in 1937."
Production numbers you have are correct: those are from TsAGI book "Samoletostroenie v SSSR 1917-1945". A
total of 384 I-15s was made between 1934 and 1936.
Spain received 131 I-15. (from Abrosov and Maslov).
HTH,
KL