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).
Report page detailing tests on blowers, carburetter and ignition systems, and engine performance metrics like horsepower and BMEP.
| Identifier | ExFiles\Box 148\2\ scan0097 | |
| Date | 28th November 1938 | |
| -4- Rm{William Robotham - Chief Engineer}/FWK.8/JH.28.11.38. Various other types of blowers have been tested - both centrifugal and eccentric vane type. For commercial use however the roots type gains on its reliability and its far more suitable C.F.M. velocity curve. (d) CARBURETTER ETC. An orthodox Zenith carburetter is used. The fuels employed were generally 87 octane value (DTD 230 in this Country) and on occasions the standard commercial fuel of 72 octane. (e) Ignition etc. Coil ignition is used, the type being the latest Delco Coil capable of firing a .030" sparking plug gap. 14 m.m. plugs are used with special insulation similar to Corundite. A rough sketch of the engine appears elsewhere in this report. 2. Performance etc. (a) Horsepower. This particular engine has a safe rev. limit of 3,000 r.p.m. although future engines are to be made, and no doubt by this time have been, in which the rev. limit will exceed 4,000 r.p.m. It is generally agreed that the engine will attain its maximum brake horsepower slightly above this speed as the power curve shows only a slight tendency to fall off. The 162.5 cu" engine develops 100 BHP. The 100 cu" " " 75 BHP. both at 3,000 r.p.m. The supercharger in each case absorbs about 15 HP. The BMEP in the 162.5 cu. in. engine at 3,000 r.p.m. on full load is thus in the neighbourhood of 8' lbs. sq.in. and for the 100 cu.in. engine is slightly higher. | ||