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).
New ignition advance characteristics required with a high compression head.
| Identifier | ExFiles\Box 27a\1\ Scan182 | |
| Date | 8th December 1934 | |
| x4013 8.12.34. SLEATOR, FRANCOBRIT, PARIS. NEW IGNITION ADVANCE CHARACTERISTIC REQUIRED WITH HIGH COMPRESSION HEAD HENCE DELAY. ROBOTHAM, ROYCAR. | ||