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Title: Su-2 Engine position in cowling Post by: warhawk on August 16, 2016, 10:45:30 PM Hi,
I've been looking at some Su-2 cutaways, and one thing that struck me odd was the position of the engine - why is it so deep inside the cowling, and not nearer to the edge as usual? Or the other way around - why isn't the cowling (and the prop axis) shorter? (http://www.airwar.ru/image/idop/bww2/su2/su2-2.gif) Title: Re: Su-2 Engine position in cowling Post by: Massimo Tessitori on August 17, 2016, 11:51:26 AM Hi,
maybe for a long reduction gear? Regards Massimo Title: Re: Su-2 Engine position in cowling Post by: John Thompson on August 17, 2016, 04:51:52 PM I don't know a lot about Russian aircraft engines, but it seems to me that all of the Shvetsov M-8X series of engines had this long reduction gear housing. If you look at cutaways of them, the various Lavochkin fighters using the ASh-82 (or M-82, if you prefer) show the same setback of the engine cylinders within the cowling, like the Su-2 with its M-87 and M-88. Radial engines like the M-62 with direct drive and therefore no gearing were installed much closer to the cowling face.
John Title: Re: Su-2 Engine position in cowling Post by: learstang on August 17, 2016, 06:31:45 PM In the case of the ASh-82 (M-82), it may have had something to do with the very streamlined cowlings these engines were installed in, as with the La-5, the La-7, and the Tu-2. Having the engine set back from the opening allowed for a more tapered cowling.
Regards, Jason Title: Re: Su-2 Engine position in cowling Post by: warhawk on August 17, 2016, 09:11:32 PM Thanks for the explanations.
Having the engine set back from the opening allowed for a more tapered cowling. But why doesn't it taper then on early Su-2s? Guess we'll never get inside the minds of 1940s aircraft designers... ;) Title: Re: Su-2 Engine position in cowling Post by: 66misos on October 31, 2016, 08:25:25 AM Hi,
not direct answer for your question but this photo nicely shows Su-2 engine: (http://www.modelforum.cz/download/file.php?id=1245339) Note part of the engine cowling on the ground behind the main landing gear. regards, 66misos Title: Re: Su-2 Engine position in cowling Post by: Massimo Tessitori on November 01, 2016, 08:37:44 AM Hi Misos,
really a good one. Thank you for sharing it. What is your source? All those thin rods to keep the frontal ring into position are noteworthy. Regards Massimo Title: Re: Su-2 Engine position in cowling Post by: 66misos on November 02, 2016, 09:31:24 PM Hi Massimo,
I have found it at Czech Modelforum, unfortunately without any description. I wonder how clean is that engine. Regards, 66misos Title: Re: Su-2 Engine position in cowling Post by: Graham Boak on February 28, 2017, 11:43:26 AM A couple of possibilities.
The long reduction gear housing could be partly to allow for fitting of a cooling fan or shutters. The shorter nose on early Su 2s could be because they didn't have the M-82. |