Various proposed solutions for piston knock trouble in the Phantom engine.
| Identifier | ExFiles\Box 48\1\ Scan173 | |
| Date | 15th October 1925 | |
| To Hs. {Lord Ernest Hives - Chair} from R. {Sir Henry Royce} c. to CJ. BY. {R.W. Bailey - Chief Engineer} X4190 R5/M15.10.25. PHANTOM PISTON TROUBLE - KNOCK. X.4190 X.8040 (1) These pistons were O.K. on Silver Ghost(1907 40/50 historic RAC 15,000 miles trial) and Goshawk(Aero Engine)(Codename for 20HP Car / Aero Engine after Kestrel(Aero Engine)), but imperfections are manifest. (2) Make no attempt at splitting the pressure side. (3) Keep the pistons the same way round. (4) I agree to the isolation, namely, slit on pressure side, but not so far round as non-pressure split side. (5) For two reasons there is much more flexibility at the bottom than the top, owing to the piston pin bosses. Can we isolate skirt from the piston pin bosses - i.e. the same as a trepanned cut taken inside present piston up to horizontal slit - (see sketch) SEE ORIGINAL FOR SKETCHES. (6) 'Z' slotting is not the best - E. {Mr Elliott - Chief Engineer} suggests this is better, but little can be gained on slight diagonal. (7) Make a piston thus :- SEE ORIGINAL FOR SKETCH. (8) We do not think the one suggested by Mr. Lovesey would be good. We make many composite ones, but we got no really good results until we split on the non-pressure side. R. {Sir Henry Royce} | ||
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).