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 measurements taken on an engine with .020 tappet clearance.
| Identifier | WestWitteringFiles\U\May1930-July1930\ Scan053 | |
| Date | 23th May 1930 guessed | |
| ACTUAL VALVE TIMING TAKEN ON ENGINE WITH .020 TAPPET CLCE. | CAMSHAFT | 116° | 112° | 110° | |------------|------------|------------|------------| | IN. OPENS | 13° A.T.C. | 7° A.T.C. | 16° A.T.C. | | IN CLOSES | 48° A.B.C. | 43° A.B.C. | 37° A.B.C. | | EX. OPENS | 42° B.B.C. | 43° B.B.C. | 28 B.B.C. | | EX. CLOSES | 2° A.T.C. | 5° A.T.C. | 4° A.T.C. | ABOVE ARE THE BEST TIMINGS FOUND DURING TWIN CARB TESTS ON "JAPAN". aeb. | ||