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 detonation tests comparing different cylinder heads and compression ratios.
| Identifier | ExFiles\Box 124\2\ scan0283 | |
| Date | 17th December 1940 | |
| - 6 - Rm{William Robotham - Chief Engineer}/Wym.{G. Harold Whyman - Experimental Manager}2/RH.{R. Hollingworth}17.12.40. From the attached graph it can be seen that although its detonating characteristics are greater than the B.111 engine, it is like the B.111 head, not so susceptible to the type of fuel used. The third cylinder head tested was another EB.3844 that had .100" machined off the fact, thus raising the compression ratio to 6:9:1 and the capacity to 112 cc's. This definitely spoilt the engine from a detonation point of view, inasmuch as on SHELL spirit, it was 2º worse than the Exs.1383 head the ignition having to be set at 16º FTDC. It is also the worst head we have so far tried for continueing to run after switching off. Comp ratio is responsible for this, because at 6:25:1 this type of head is not bad for this particular complaint. (Continued) | ||