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).
After 15,000-mile test report giving impressions on the gearbox and clutch performance of car 6-B-IV.
| Identifier | ExFiles\Box 83\2\ scan0332 | |
| Date | 30th April 1938 | |
| Rm.{William Robotham - Chief Engineer} C. BY.{R.W. Bailey - Chief Engineer} (crossed out) C. Da.{Bernard Day - Chassis Design} (crossed out) C. Mx.{John H Maddocks - Chief Proving Officer} (crossed out) ----- 200A Da{Bernard Day - Chassis Design}/Hdy.{William Hardy}4/G.30.4.38. I WALLER noted. 6-B-IV. AFTER 15,000 MILE TEST. With reference to my run on this car to West WitteringHenry Royce's home town last week-end, the following notes give my impressions of various features of this car. Gearbox. The overdrive was very silent. I was not conscious of hearing it. With the windows closed an appreciable reduction of engine noise was noticeable with the overdrive in use, especially at speeds above 55 - 60 where the characteristic 'thump' from the Bentley engine was considerably in evidence. The journey to West WitteringHenry Royce's home town was made as fast as was considered safe, and the only changes made from direct drive were to the second speed, the overdrive not being used, as it gave no increase of speed. Changes to 2nd. speed are quite a different matter from changes to 3rd. on the old box, as it is necessary to go through the gate into an unsynchronised gear with a much larger difference of speed to adjust. My feeling is that the loss of the 3rd speed on the Bentley is regrettable. Mercedes and Maybach appear to consider that five speeds are justified. Clutch. This required depressing the full four inches to the floorboard when gear changing. Engagement from rest was inclined to be sudden. I have not yet been able to find out why so much pedal travel was required. Movement to take up clearance was greater than standard, being 1.0" against .625 - .750 as measured on standard clutches at the centre of the pedal plate. Standard clutches appear to require about 2¼" movement to disengage fully. This includes clearance. The clutch on 6-B-IV. has a servo spring, but | ||