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).
Comparison of specifications for Stepped and Plain type compression rings.
| Identifier | ExFiles\Box 144\3\ scan0060 | |
| Date | 23th June 1936 guessed | |
| -3- Compression Rings (Stepped type). Tangential load = 5.234 lbs. Dia. of ring. = 3.312 Width (total) = .123 Width (bearing) = .073 Radial thickness = .142 Cylinder wall pressure = 43.3 lbs./sq.in. Ratio Cylinder dia./Radial thickness = 23.3 : 1 Compression Rings (Plain) Tangential load = 5.875 lbs. dia. of ring. = 3.312 Width = .123 Radial thickness = .133 Cylinder wall pressure= 28.85 lbs/sq.in. Ratio Cylinder dia./Radial thickness = 24.9 :1 The figures given for the wall pressure of the Chevrolet rings were taken from one ring of each type and of course may not be a true average, in fact Messrs. Hepworth & Grandage who make these rings in this country say they are rather high, particularly the figures for the Scraper ring. we know that our own | ||