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).
Performance comparison graph for two different vertical SU carburettor distribution setups.
| Identifier | ExFiles\Box 102\1\ scan0063 | |
| Date | 11th December 1931 guessed | |
| R.M. 52 COMPARISON OF DISTRIBUTION VERTICAL S U 112° CAMSHAFT WITH TWO INLET CAMS. HIGH LIFT ROCKERS OPEN EXHAUST. INLET VALVE DIA. 1·4 WITH MIN HEAD CLEARANCE OF .225 ROUND VALVE. VERTICAL CARB. 1 7/8 THROTTLE C/R 5·65-1 PIPE V.1207 A.{Mr Adams} AIR VALVE AT RT. ANGLES TO CRANK B. PARALLEL TO ENGINE B.H.P. R.P.M. B.M.E.P. IND. DEP. Valve Timing Diagram: TO C 12 Ex. 59 013 CLCE IN 50° DISTRIBUTION A DEFINATELY BETTER THAN B ESPECIALLY AT LOW SPEEDS DISTRIBUTION A EXCELLENT OVER WHOLE RANGE | ||