Alteration to the Goshawk II cylinder head's double inlet and exhaust ports to reduce resonance.
| Identifier | WestWitteringFiles\G\October1921\ Scan60 | |
| Date | 15th October 1921 | |
| To DA. {Bernard Day - Chassis Design} from E. {Mr Elliott - Chief Engineer} Copy to CJ. " " HS. {Lord Ernest Hives - Chair} ORIGINAL X4227 X4225 RE "GOSHAWK(Aero Engine)(Codename for 20HP Car / Aero Engine after Kestrel(Aero Engine)) II" CYLINDER HEAD - ALTERATION OF SHAPE OF DOUBLE INLET AND EXHAUST PORTS TO REDUCE NOISE. RECEIVED 3 E5/G18o/20/2C 15 OCT 1921 We send you herewith drawing No.Lec.1465 showing the double ports of the "Goshawk(Aero Engine)(Codename for 20HP Car / Aero Engine after Kestrel(Aero Engine)) II" cylinder head made with a round contour where the point at present exists at the junction of the pockets. This, it is hoped, will modify the shape of the back water pipe, enlarging its mouth to such an extent that resonance will disappear. 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).