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).
Specification for the Big Bore Bentley exhaust system.
| Identifier | ExFiles\Box 86\3\ scan0103 | |
| Date | 19th November 1935 | |
| To BY & E.{Mr Elliott - Chief Engineer} X223 Hs{Lord Ernest Hives - Chair}/Wym.{G. Harold Whyman - Experimental Manager}13/KW.19.11.35. Re Big Bore Bentley Exhaust System. Herewith the specification of the exhaust system for the Big Bore Bentley. (a) Standard front expansion box and downtake pipe. (b) Front intermediate pipe EB.1503 as present standard. (c) Front silencer to standard design but using 16 SWG. material for silencer shell EB.421 and Sleeve EB.1504, the two ends EB.778 to remain in 14 SWG. material. (d) Rear intermediate pipe EB.978 to be made in 16 SWG. material. This pipe will also require to be approx. 6.00" longer to suit new rear silencer. (e) Rear silencer to drawing Rm.{William Robotham - Chief Engineer}10 (attached), using 16 SWG. material for outer shell, top hat and inner pipe - the two ends to be made in 14 SWG. material. (f) Tail pipe EB.1086 to be made in 16 SWG. material. All the lightened parts mentioned above have satisfactorily completed 15,000 miles on 5-B-IV. We also require more ground clearance at the rear end of the tail pipe, as per our verbal conversation with E.{Mr Elliott - Chief Engineer}, as we find that a number of tail pipes are being damaged in service through fouling the kerbstones when parking. Hs{Lord Ernest Hives - Chair}/G.H. Whyman. | ||