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).
Request to produce detail drawings for three new split skirt pistons with specific design particulars.
| Identifier | ExFiles\Box 148\1\ scan0237 | |
| Date | 28th February 1940 | |
| 1256 Ev.{Ivan Evernden - coachwork} c. Ev{Ivan Evernden - coachwork}/HH. Rm.{William Robotham - Chief Engineer}11/CTS{C. Trot Salt - Carburation}/ML.28.2.40. PISTONS. Will you please produce three new detail drawings for split skirt pistons, to suit the various bores for our range of engine. Particulars of this piston should be as follows:- (1) Basic Design; Material thickness; etc., as EB.1299, which was standard production for the first 300 3½ litre Bentley units. Reason: (a) This piston is lighter than anything we have been able to get from Aerolite, and; (b) It never gave any trouble. (2) Centre of gudgeon pin to block face, to be 2.300. making pistons flush top. (3) All land dimensions, and skirt grinding as last Production Wraith series. Rings should be based on the B.V. proposed for production:- EB.4737-8-9. Piston and rings to be tin-plated, and as both will be produced by the Light Production Co., the rings will be plated in accordance with their "Cellotin" process. Rm{William Robotham - Chief Engineer}/CTS.{C. Trot Salt - Carburation} | ||