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).
Performance graph and analysis for raised crown pistons with a 7:1 compression ratio.
| Identifier | ExFiles\Box 134\2\ scan0192 | |
| Date | 1st February 1939 | |
| -5- Rm{William Robotham - Chief Engineer}/Swd1.2/KH.1.2.39. ④ AS CURVE ③ WITH PD.304 RAISED CROWN PISTONS AS DESIGNED 7:1 COMP RATIO MAX. POWER NON DETONATING. MEP lbs/□" RPM * IGN ADV °BTDC MEP IGN Curve (4). This condition is as Curve (3) but incorporating raised crown pistons PD.304, which raises the compression ratio to 7.0 : 1. This gives a good MEP curve with a maximum of 130 lbs/sq.in. at 2000 r.p.m., but is very bad for detonations and necessitates losing 15-20 lbs/sq. MEP to be clear. Continued. | ||