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).
Supply and specification of oversize Bentley pistons and rings for a trials car.
| Identifier | ExFiles\Box 146\2\ scan0239 | |
| Date | 21th June 1937 | |
| W/P - Sr/VA. c. to D/BP. 1245' Rm{William Robotham - Chief Engineer}/Mths.{Reg Matthews}9/JH.21.6.37. BENTLEY PISTONS. We have today received the oversize pistons for your trials car, and we are arranging to have these despatched to you as soon as possible, they are as stated previously of the latest type complete with high pressure scraper ring. With reference to your memo. Sr/VA.9/ET.14.6.37. in which you state you require high pressure scraper rings for 3½ litre Bentley .005 oversize, we have not these rings in stock since they were never standardised on 3½ litre chassis. We have however some rings we ordered for experiments we intended to carry out here but which will no longer be required, they are similar to EB.3122 rings but they are only suitable for standard bores. Since you require these rings only for .005 oversize, we pressume you wish to fit these in bores without reboring, in which case they should be suitable since the maximum wear takes place at the position opposite the top compression ring and therefore the wear opposite the scraper ring should be quite small. We have no official number for these rings and would therefore like to hear your results with them with a view to sending out a depot sheet and ordering the necessary rings and allotting them an official number. Will D/BP. please note and credit all parts accordingly. SECTION 5040. 6 EB.3151 piston .010 oversize. 12 E.61153 compression rings. 6 EB.3122 scraper ring .010 oversize. 6 EB.2845 Gudgeon pin. 12 EB.2300 end pads. 12 scraper rings similar to EB.2378. except that wall pressure is 32.0 lb/sq.in. Rm{William Robotham - Chief Engineer}/Mths{Reg Matthews}, | ||