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).
Test results for car and engine speeds with different silencer configurations.
| Identifier | ExFiles\Box 25\3\ Scan034 | |
| Date | 15th July 1912 guessed | |
| X634 4100. Car & Engine Speeds. No 6. engine 60501 (20 pinion) .85 throat. wt.3350lb 4th gear 50 m.p.h. Engine speed 1320 revs. 3rd gear 45 m.p.h. (maximum) Engine revs 1430. rattle at 1110 revs. 2nd gear. 30 m.p.h. (maximum) low gradient. 1 in 20. Engine revs 1630. Rattle at 1180. (Above tests with silencer without baffle plates.) Tested next day with silencer with baffle plates, power reduced. | ||