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).
Modifications and performance test results for the 'Hawk' engine X.3320 and X.2935.
| Identifier | ExFiles\Box 36\2\ scan 078 | |
| Date | 18th October 1918 | |
| B.R. 235a (500 T) (S.D.) 408. 26-4-17.) Bm. 2/156/15. X.2935 EHL/LGS.10.18. To R.{Sir Henry Royce} from EH. c. to CJ. c. to E.{Mr Elliott - Chief Engineer} c. to BY.{R.W. Bailey - Chief Engineer} RE "HAWK" ENGINE X.3320. X.2935. We have had Capt. Briggs and Lieut. Perry of the Airship Section at the Works, to see the "Hawk" engine. We shewed them results which had been obtained with different induction pipes; they considered the 6 cylinder pipe with the short branches and the carburetter fixed above the engine bearer tubes was one they preferred. We explained to them that we are making another induction pipe similar to the latest "Condor" but they pointed out that Brazil Straker's must have all the drawings immediately. We reduced the size of the throat on a "Falcon" carburetter to suit this engine. We found a 32 mm. throat gave us the best results. We arranged for the A.I.D. Inspector at Brazil Straker to come to Derby and see the performance of the "Hawk" here, so that ther would be an official record of what the engine had done. The results were as follows:- REVS HP. Cons.lbs.per HP. Hour. Remarks. -------------------------------------------------------------------------- 1900 120 Slow running. 1800 118 225 r.p.m. 1700 114 1600 112 .481 1500 105 .486 Consumption 1400 98 .478 9/10 throttle at 1300 90 .486 1500 r.p.m. .515 1200 82 lbs.per HP.hour. 1100 74 1000 68 | ||