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).
Indicator cards comparing engine pressures with and without detonation.
| Identifier | ExFiles\Box 148\2\ scan0103 | |
| Date | 28th November 1938 guessed | |
| CYLINDER HEAD INTAKE MANIFOLD EXHAUST MANIFOLD IC BC TC IO BC TC INDICATOR CARD SHOWING NO DETONATION CYLINDER HEAD INDICATOR CARD SHOWING DETONATION IC. — INTAKE CLOSES EC. — EXHAUST " TC. — TOP CENTRE BC. — BOTTOM CENTRE IO. — INTAKE OPENS EO. — EXHAUST OPENS. | ||