All production Type 18s had M-25V (1000hp) with normal mechanically driven two-stage supercharger and four ShKAS mgs.
New
more advanced and powerful M-62 engine was designed by Arkadij D. Shvetsov team at Perm aero-engine factory (GAZ-19). Retaining the cubic capacity of M-25V, new engine was equipped with two-stage supercharger, gaining 225hp of power on expense of 46kg extra weight.
M-62 was rushed to production, and in early 1939 it was fitted to the I-16 Type 10 airframe. AV-1 automatic propeller (differed by larger blunt spinner and wide chord blades) was fitted. Other new external features included additional air intake on top of the engine cowling and paired exhaust stacks in the lower cooling/exhaust ports.
Thanks to the more powerful engine engine and advanced propeller, Type 18 had a considerable increase in performance, specially speed and ceiling. Handling also became better, aircraft was more stable on sharp loops and turns than all predecessors. Landing also was easier. The only parameter to suffer was range (due to more consuming engine), but problem was solved by provision of external underwing fuel tanks (developed on the I-16 Type 20 testbed).
Despite series production, the I-16 Type 18 remained and interim variant to keep production busy until arrival of more advanced M-63 engine.
http://www.ctrl-c.liu.se/misc/ram/i-16-t18.htmlTho if I rememeber right not all type-18s had the super-charged M-25V, "otherwise known as the M-62".
I always thought type 18s were better armed but it appears your right. In order to have a better armed one we'd need the 17, or even better, the 24. The later 24 versions had the M-63 at 1,100 HP, drop tanks, 2 7.62 in cowling, 2 20mm SHVAK in wings, and could launch RS-82 rockets. Since it was first used in 1939 it would probably still fit early war. Unfortunatly it wouldnt be as nimble as the type-18, but that would be the trade off.
I dont know how many M-24s were built. In fact other then overall I-16 production I cant find anywheres that tells me how many of each model were built.