Design specifications for a cast iron piston for the Goshawk II engine.
| Identifier | WestWitteringFiles\G\September1921\ Scan20 | |
| Date | 1st September 1921 | |
| To EA. from E. {Mr Elliott - Chief Engineer} Copy to CJ. " " WOR. {Arthur Wormald - General Works Manager} " " HS. {Lord Ernest Hives - Chair} ✓ " " HX. ORIGINAL RECEIVED X4224 RE CAST IRON PISTON FOR "GOSHAWK(Aero Engine)(Codename for 20HP Car / Aero Engine after Kestrel(Aero Engine)) II" - LEC.1447. We send you herewith the above drawing which will enable you to test cast iron pistons for "Goshawk(Aero Engine)(Codename for 20HP Car / Aero Engine after Kestrel(Aero Engine)) II". Mr. Royce decided that this piston should have no scraper ring as he wished the cast iron surface to be amply lubricated owing to its greater possibilities of seizing as compared with aluminium. He also decided that this piston should be un-split, and that only aluminium pistons for "Goshawk(Aero Engine)(Codename for 20HP Car / Aero Engine after Kestrel(Aero Engine)) II" should be split in the manner of our 40/50 H.P. We do not know what compression ratio you are using, as the compression pressure only was given in the experimental report, so we should be glad if you would adjust the height of this piston accordingly. The weight of the spring ring for securing for securing the gudgeon pin and the extra metal for the spring ring groove should be counter-balanced by thickening up the opposite wall of the piston when detailing. E. {Mr Elliott - Chief Engineer} | ||
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).