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).
Data table showing detonation and ideal ignition advance for a silenced EB. 615 cylinder head.
| Identifier | ExFiles\Box 86\1\ scan0192 | |
| Date | 20th March 1936 guessed | |
| DETONATION AND IDEAL IGNITION ADVANCE. EB. 615 Cylinder Head. (Silenced.) | R.P.M. | I.M.E.P. | B.H.P. | PTS/BHP/HR. | IGN. ADV. | DETN PT. | |---|---|---|---|---|---| | 4000 | 86.2 | 97.6 | .615 | 33 | NIL | | 3750 | 94.5 | 100.1 | .570 | 31 | * | | 3500 | 98 | 97 | .570 | 30 | * | | 3250 | 103 | 93.6 | .566 | 30 | * | | 3000 | 107 | 90.6 | .566 | 28 | * | | 2750 | 110.4 | 85.8 | .545 | 26 | * | | 2500 | 114.3 | 80.7 | .545 | 25 | * | | 2250 | 116.3 | 74.2 | .552 | 24 | * | | 2000 | 118.1 | 67 | .568 | 24 | * | | 1750 | 118.2 | 58.5 | .608 | 24 | * | | 1500 | 117.8 | 50.0 | .623 | 24 | * | | 1250 | 115.7 | 40.9 | .595 | 22 | S | | 1000 | 111.5 | 31.6 | .632 | 21 | 21 | | 750 | 96.1 | 20.4 | .686 | 16 | 36 | | ||