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).
Research and standardisation committee report on a ringless piston design and its performance.
| Identifier | ExFiles\Box 27\2\ Scan263 | |
| Date | 9th June 1934 | |
| Copy. I.A.E. RESEARCH AND STANDARDISATION COMMITTEE. Research Department, No. 7167. Class 255. 5, Bolton Road, Chiswick W.4. June 1934. A Ringless Piston. ------------------ Motor Transport, June 9th. 1934, P.9. ------------------------------------ A ringless piston has been developed by J.{Mr Johnson W.M.} Campbell (Darwen) Ltd. The piston consists of a cast iron shell inside which two D-section alloy blocks, supported from the head, carry the gudgeon pin. The piston walls are thin so that distortion of the cylinder can be accommodated. The clearance is 0.010 in. at the head and 0.0015 in. about 1½ in. down the skirt. Campbell pistons have been fitted to seven standard 36 h.p. Leyland vehicles, and it is stated that after 15,000 miles no falling off in efficiency was experienced. The maximum cylinder wear at the end of 9000 miles was 0.00025 in. The oil consumption increased from 2000 to 1000 m.p.g. during the running-in period, but thereafter remained constant. C.G.W. | ||