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).
The Goshawk 11 engine, detailing further testing on pistons, clutch performance, and wheel/tyre specifications.
| Identifier | ExFiles\Box 180\M1\1\ img020 | |
| Date | 19th August 1921 | |
| To R.{Sir Henry Royce} from Hs.{Lord Ernest Hives - Chair} c. to CJ. c. to E.{Mr Elliott - Chief Engineer} c. to De. c. to BY.{R.W. Bailey - Chief Engineer} c. to Wor.{Arthur Wormald - General Works Manager} ORIGINAL COPY OF REPORT BY Mr.T.D.W-ARIS & F.C. Hs{Lord Ernest Hives - Chair}2/LG19.8.21. X4219 RE. GOSHAWK ENGINE. We have run Goshawk 11. engine a further 17 hours since it was dismantled. The lower compression pistons have reduced detonations. We cannot measure any drop in horse power. The compression by gauge is now 83 lbs. We fitted to the clutch, springs which were 100 lbs. instead of 80 lbs. at their normal length. The clutch held alright for a few hours and then commenced to slip. We let it slip considerably before we dismantled it so that we could see what would happen if it was abused. When it was dismantled we found that the thin steel disc had been blue with heat but it had come to no harm and was still running true. Ferodo discs were highly glazed on the surface. There were no signs of oil having got into the clutch. We are now fixing springs which give a pressure of 120 lbs. at the normal position. The clutch trunnion has given no trouble on the last run. With reference to the wheels for Goshawk 11. The tyre makers inform us that the equivalent tyre for the 820 X 120 is 32 X 4 1/2 in the straight sided tyres. We have actually measured the difference in diameter between a 820 X 120 beaded edge tyre and a 32 X 4 1/2 straight sided tyre - the width of the tyres is the same. The straight sided tyre is 1" larger in diameter contd:- | ||