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).
Blueprint sketch showing modifications to a cylinder head to improve power output.
| Identifier | ExFiles\Box 86\1\ scan0144 | |
| Date | 15th March 1935 | |
| B.V. 80 1.800 1.750 .825 RAD. .075 .960 1.500 DIA. INLET VALVE 1.300 DIA. EXHAUST VALVE SKETCH SHOWING MODIFICATIONS CARRIED OUT TO IMPROVE POWER OUTPUT OF CYLINDER HEAD TO LEC 3662 R.H.u 15.3.35 | ||