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).
Proposal to test the experimental 4.EX chassis, listing its five new features.
| Identifier | ExFiles\Box 158\4\ scan0008 | |
| Date | 27th February 1920 | |
| X.3733 Extract from Hs{Lord Ernest Hives - Chair}2/LG27.2.20. F X.3764. RE 4.EX CAR. I propose to bring 4.EX chassis (the latest experimental chassis) to West WitteringHenry Royce's home town next week. This chassis is fitted with the following new features - X.3583. 1. Thermostat Control. 3Y54-a X.3881. 2. Cast Iron Pistons - split type. X.3630. 3. Magneto fixed at an angle. X.3699. 4. Serrated Magneto Drive. X.3733. 5. Pinned Tappets. | ||