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 .020 tappet clearance, showing results from twin carburetor tests.
| Identifier | ExFiles\Box 6\7\ 07-page093 | |
| Date | 10th January 1932 | |
| 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 | 49° 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 'JAPAX'. 10/1/32 | ||