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).
Graph comparing the power output of two different B.60 engine configurations with an open exhaust.
| Identifier | ExFiles\Box 123\5\ scan0105 | |
| Date | 3rd October 1938 guessed | |
| B.60 POWER COMPARISON (OPEN EXHAUST) S.56 ① B.60. 6.4:1 COMP. RATIO MOCK-UP WRAITH INDN NO DYNAMO OR FAN. VALVE TIMING WITH .030 CLEARANCE. IO. 7° PTDC EO. 42° BBDC IC. 30° PBDC EC. 33° BTDC ② WRAITH III. 6.5:1 COMP. RATIO AEROLITE RAISED CROWN PISTONS STD. WRAITH INDN SYSTEM. DYNAMO BUT NO FAN. VALVE TIMING WITH .025 CLCE. IO. 6.7° PTDC EO. 41° BBDC IC. 39° PBDC EC. 8° BTDC B.H.P. M.E.P. LBS/D" R.P.M. | ||