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 performance report detailing issues with a cylinder head, including detonation, ignition timing, and rough running.
| Identifier | ExFiles\Box 124\2\ scan0280 | |
| Date | 17th December 1940 | |
| - 3 - Hm{Capt. W. Hallam - Head Repairs}/wm.c'RH.{R. Hollingworth}17.12.40. Good slow running and idling was obtained with a minimum tappet clearance of .012" Inlet and .012" Exhaust. We found this head infinitely worse than the B.111. head for detonations, and after obtaining the correct curve line, we had to set the ignition at 14° PIDC to avoid detonations when using SHELL No.1 spirit. It can be seen from the accompanying graph that this head is very susceptible to detonations according to the type of fuel used, as it is also to load applied, and in addition to making the engine feel much rougher, it has a tendency to continue running after switching off and finally backfiring. (Continued) | ||