Warbird Information Exchange

Does anyone know how to read the model designations for the Wasp 1340 engine. An example would be S1D1, or SR-1340.
The only know letters are "G" for geared engine, and "R" for radial engine. What would the "S" stand for. As all 1340s have blowers, I can not see where it would mean supercharger.
The word Wasp-XX was used for civilian engines, and the R1340-XX was used for military. Would S1D1 mean a derivative of the "D" model? Any help would be appreciated.

Cheers,

P&W used two systems for naming their engines. One was for commercial use and other for Army/Navy standards, which means the latter ones have two numeric names. Both systems defined prisicely the engine with its modifications making changing the plant and providing the parts posssible.

S1D1 would be:
S- Single stage single, speed supercharger rating, 1 - suffix used to describe changes in supercharging rating , D - engine series, 1- suffix used to describe type of supercharger (e.g. 1-9 for single staged, single speeded Double Wasp). The full designations covers the details of reduction gearing propeller speed and so on. The lack of other suffixes and prefixes should mean it is unchanged otherwise basic model.

R - 1340 is a military designation and covers all the information above with numeric suffix it should carry in the end. The navy and Army engines had different suffixes, even if the engines were the same. At least shuold have. With time the idea have been abandoned. Or was it only for a while?

I am surprised to see S in front of R-1340. In my opinion its mixing the two systems, but I am not sure, as all I have written here is based on R-2800 designation methods. It was P&W system, but well, one thing You can be sure is You won't put a helmet on Your head upside down.

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Here is the Type Certificate Data Sheet on the 1340 from the FAA for FAA certificated engines:

http://rgl.faa.gov/Regulatory_and_Guida ... L/5E-2.pdf

That may answer a few questions.

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Bill Goebel
aka TPFD

Vintage Aircraft Services
Aircraft restoration and rebuilding
Rhome, TX

http://www.vintageaircraftservices.net

Thank you gentlemen for the help. The Canadian data sheet is a perfect example of 'what are you trying to say?' Note the first engine listed is a SR-1340(military) but also known as a S1D1 in civilian terms. And....this SR-1340 does not have the double digit number after the 1340, as in R-1340-22, or is it R1340-22??? (By the way even is Navy, odd is Army).
Best I can tell is that "A" thru "H" are the letters for the engine. (Not sure what to do with AN-1) And that a "H" is always 600HP.

Was all this done to confuse the enemy? Or is the enemy 'us' ?

Cheers

AN form - joint coordination with Army and Navy.

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