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).
Table of actual valve timing data taken on an engine with a .020 Tappet Clearance.
| Identifier | ExFiles\Box 5\4\ 04-page239 | |
| Date | 27th May 1918 | |
| ACTUAL VALVE TIMING TAKEN ON ENGINE WITH .020 TAPPET CLE CAMSHAFT | 116° | 112° | 115° In. Opens | 1½° A.T.C. | 7° A.T.C. | 16° A.T.C. In. Closes | 47° A.B.C. | 43° A.B.C. | 37° A.B.C. Ex. Opens | 42° B.B.C. | 43° B.B.C. | 29° B.B.C. Ex. Closes | 2° A.T.C. | 5° A.T.C. | 4° A.T.C. ABOVE ARE THE BEST TIMINGS FOUND DURING THESE SAME TESTS ON JAPAN. STAMPED BOX: T. ROOM 27 MAY 1918 S.D.V. | ||