Performance estimate comparing a Goshawk II motor applied to a Goshawk I engine with a different reduction ratio.
| Identifier | WestWitteringFiles\G\August1921\ Scan65 | |
| Date | 30th August 1921 | |
| To R. {Sir Henry Royce} from EFC. {E. Fowler Clarke - Electrical Engineer} ORIGINAL EFC {E. Fowler Clarke - Electrical Engineer} 1/T30.8.21. c.c. to CJ. c.c. to E. {Mr Elliott - Chief Engineer} c.c. to Da. {Bernard Day - Chassis Design} c.c. to Da {Bernard Day - Chassis Design} /T. } at W. Wittering. X.4384 - "GOSHAWK(Aero Engine)(Codename for 20HP Car / Aero Engine after Kestrel(Aero Engine)) II" MOTOR APPLIED TO "GOSHAWK(Aero Engine)(Codename for 20HP Car / Aero Engine after Kestrel(Aero Engine)) I" ENGINE. We attach table showing our estimate of the performance of the Goshawk(Aero Engine)(Codename for 20HP Car / Aero Engine after Kestrel(Aero Engine)) II motor as applied to Goshawk(Aero Engine)(Codename for 20HP Car / Aero Engine after Kestrel(Aero Engine)) I engine with a reduction ratio of 14.4 instead of 8.4 as on Goshawk(Aero Engine)(Codename for 20HP Car / Aero Engine after Kestrel(Aero Engine)) II. It will be seen that the relative performances should be approximately in accordance with the following table :- Quantity. Goshawk(Aero Engine)(Codename for 20HP Car / Aero Engine after Kestrel(Aero Engine)) II. Goshawk(Aero Engine)(Codename for 20HP Car / Aero Engine after Kestrel(Aero Engine)) I. Motor volts. 9.26 10.1 Amperes. 137 95.5 Electrical H.P. 1.63 1.29 Motor speed. 810 1363 Engine speed. 96.5 94.5 B.H.P. .85 .835 Efficiency. 50% 64.6% It will be remembered that the calculations of the performances are made for these for the Goshawk(Aero Engine)(Codename for 20HP Car / Aero Engine after Kestrel(Aero Engine)) II engine in a quite cold condition, so that in nearly every case of starting the figures of operation here cited for Goshawk(Aero Engine)(Codename for 20HP Car / Aero Engine after Kestrel(Aero Engine)) II are modified to more nearly those corresponding to Goshawk(Aero Engine)(Codename for 20HP Car / Aero Engine after Kestrel(Aero Engine)) I engine. EFC. {E. Fowler Clarke - Electrical Engineer} R R 322v (100 1) (2' H 168' 10-12-30) O 2071 | ||
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).