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).
Standard 8 valve timing specifications for inlet and exhaust valves, and valve springs.
| Identifier | ExFiles\Box 158\5\ scan0108 | |
| Date | 13th March 1941 | |
| 1860 To Rm{William Robotham - Chief Engineer}/Wym{G. Harold Whyman - Experimental Manager}, From Rm{William Robotham - Chief Engineer}/Clm.{D. D. Clapham} Rm{William Robotham - Chief Engineer}/Clm.{D. D. Clapham}20/ST.13.3.41. STANDARD 8 VALVE TIMING. INLET VALVES. 1 - Valve timing - at running clearance of .012" - opens at 19° before T.D.C. closes at 120° before T.D.C. at .030" clearance - opens at 2 1/2° after T.D.C. closes at 141° before T.D.C. 2 - Valve lift = .251". 3 - Drawing of valve Rm.{William Robotham - Chief Engineer}694. 4 - Graphs of valve opening with no clearance from 0 to .030" opening and closing are attached. EXHAUST VALVE. 1 - Valve timing - at running clearance of .012" - opens at 120.5° after TDC. closes at 25 1/2° after TDC. at .030" clearance - opens at 144.5 after TDC. closes at 1 1/2° before TDC. 2 - Valve lift = .251" 3 - Drawing of Exhaust Valve Rm.{William Robotham - Chief Engineer}695 DETAILS OF VALVE SPRINGS. Free length 1.650". Choc length .900". Rate 63 lbs/in. Rm{William Robotham - Chief Engineer}/Clm.{D. D. Clapham} | ||