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).
Engine size comparisons and potential performance issues for 6 and 8-cylinder engines.
| Identifier | ExFiles\Box 134\2\ scan0049 | |
| Date | 15th July 1935 | |
| -2- Hs{Lord Ernest Hives - Chair}/Bmth.20/KW.15.7.35. Engine Size. The minimum lengths of a 6-cylinder, 3.5 bore and an 8-cylinder 3.125 bore engine are shown in the attached figure. These are obtained by grouping the combustion chambers in pairs and using the compact form which we have asked Wd.{Mr Wood/Mr Whitehead} to test. Other engine lengths for comparison are given in Hs{Lord Ernest Hives - Chair}/Bmth.6/KW.20.6.35. The engine would be about 3/4" wider and 1 1/4" lower than the standard types, and we estimate that the 6-cylinder engine would weigh about the same as the Bentley, whereas the 8-cylinder would weigh 5% more than the Wraith (because it requires a C.I. block). Engine Performance. As far as single cylinder results are concerned, we cannot yet be sure that we can eliminate the high speed detonation trouble. In any case we expect to have to use a cooled exhaust valve. The engine would probably be very rough due to the high rate of pressure rise. We anticipate that the high power engine might be a bad slow runner because the sparking plug is isolated from the inlet valves. Hs{Lord Ernest Hives - Chair}/F.Ll.Smith. | ||