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).
Summary of the testing and development position for the Big Bore 20/25 car model.
| Identifier | ExFiles\Box 101\1\ scan0132 | |
| Date | 22th January 1936 | |
| x500a To Sg.{Arthur F. Sidgreaves - MD} & Wor.{Arthur Wormald - General Works Manager} Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer}7/KW.22.1.36. Big Bore 20/25. A summary of the position that this car has reached is as follows. Subject to what may happen on a 10,000 miles test, we have cleared by bench tests and tests at Derby all the parts of the big bore 20/25 except the air intake bend and silencer. 21-G-IV now in London represents what it is proposed to make. 22-G-V is the second car of the type now at the Coachbuilders. This one will run the road test, prior to which it can be tried as the model. We consider that 21-G-IV as a type is a better car on the whole than the present standard 20/25 being sold, and furthermore that with development it can be still further improved. The fact that the idling and low speed acceleration are slightly inferior to the two mock-up schemes running on your cars can be best explained by the fact that we have had the final scheme on test three weeks on one car, the mock-up scheme more than three months on several cars. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} | ||