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 for an experimental 20 HP cylinder head with larger valves for power development experiments.
| Identifier | ExFiles\Box 103\4\ scan0008 | |
| Date | 30th May 1927 | |
| 20 H.P. POWER DEVELOPMENT EXPERIMENTS. FLAT SURFACE (MACHINED) THIS HEAD WAS PRODUCED FROM A STD HEAD CASTING BY BORING OUT THE VALVE PORTS AT THE SEAT TO 1.400 DIAM. THE PORTS AT THE INDUCTION & EXHAUST MANIFOLD ENDS REMAINED THE SAME AS STANDARD. INVERTED PLAN INLET EXHAUST 15° 1.400 DIA. 1.600 DIA. EXPL. 20 H.P. CYLINDER HEAD WITH LARGER VALVES ALL OTHER DIMENSIONS AS SHOWN ON STD CYL. HEAD DRAWING E52954. | ||