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).
Modifications to valves and spring drives for the Goshawk engine.
| Identifier | ExFiles\Box 48\4\ Scan083 | |
| Date | 8th December 1922 | |
| X4226 To BY & HS.{Lord Ernest Hives - Chair} from R.{Sir Henry Royce} c. to CJ. BJ. c. to Wor.{Arthur Wormald - General Works Manager} EP.{G. Eric Platford - Chief Quality Engineer} R1/M1 8.12.22. RE. GOSHAWKS. X.4226 X.4222 X.4221 X.3551. (1) RE VALVES X.4226. With heavy bodies I fear we are asking for a lot of HP. for a given size of valve. Possibly a change from 15° face to 30 or 45° may considerably improve reliability, but also we may require real stainless instead of quickstep. Heating an exhaust valve may also be caused by insufficient clearance, or the slow rate of opening, also slightly more metal in the head of the valve. All the foregoing you could test on the engine bed. (2) RE SPRING DRIVES X.4221. X.4222. We have received your remarks re slight slacks unavoidable in present design. You will remember that we removed these from the slipper flywheel, and we think by redesigning we can get a better scheme than even the 40/50, by avoiding the end play in the crankshaft pinion, and also halve the slack in the pins of the brake shoes. (half friction absolutely without slack.) The combination we are trying to arrange will probably fit the present space, and the spring drive damper will consist of a single plate friction clutch which also controls the end play. We now quite realise that all slack must be removed from this unit, though we previously thought it only applied to the damper flywheel. contd:- | ||