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Comparison of the Goshawk and 40/50 models focusing on displacement per ton per mile.


Identifier  ExFiles\Box 107\4\  scan0019
Date  19th July 1917
  
R.R. 199 (250T) (SD676 19-7-17) MP180865

contd:- -2-

It will be seen that based on displacement per ton per mile the Goshawk(Aero Engine)(Codename for 20HP Car / Aero Engine after Kestrel(Aero Engine)) is considerably more heavily loaded than the 40/50. It is only the increased engine efficiency on the Goshawk(Aero Engine)(Codename for 20HP Car / Aero Engine after Kestrel(Aero Engine)) compared with the 40/50 that enables it to perform as it does with the load.

Car. Guaranteed weight. Displacement of engine. cu.ins. Direct gear ratio. Low gear in each case. Displacement per ton per mile.
40/50 55 cwts. 453.3 26 m.p.h. at 1000 r.p.m. 14 X 52. 190060 cu.ins.
Goshawk(Aero Engine)(Codename for 20HP Car / Aero Engine after Kestrel(Aero Engine)). 39 cwts. 190.8 20.5 m.p.h. at 1000 r.p.m. 13 X 60 143180 cu.ins.

Present guaranteed weight of G.11. = 39 cwts.
Required weight to equal 40/50 in displacement is = 29.38 cwts. or 3290 lbs.

Hs. {Lord Ernest Hives - Chair}
  
  
From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).


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