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).
Timing diagram for a 20 HP long duration camshaft, with a comparison to the standard timing.
| Identifier | ExFiles\Box 5a\5\ 05-page058 | |
| Date | 26th May 1922 guessed | |
| LONG DURATION CAMSHAFT (20 h.p.) TIMING DIAGRAM (.010 TAPPET CLEARANCE) T.D.C. I.O. (Inlet Opens) E.C. (Exhaust Closes) 6° 8° 66° 64° I.C. (Inlet Closes) E.O. (Exhaust Opens) B.D.C. (Bottom Dead Centre) THIS CAMSHAFT IS EVOLVED BY INSERTING A 1/4" WEDGE IN THE STANDARD INLET CAM, & A 5/16" WEDGE IN THE STANDARD EXHAUST CAM, (AT THE POINT OF HIGHEST LIFT), & THEN SPACING THE CAMS AT 120°. STANDARD TIMING (.010 CLEARANCE) T.D.C. I.O. E.C. 10° I.C. 46° E.O. 48° | ||