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).
Goshawk II engine's ignition advance curve and governor modifications.
| Identifier | WestWitteringFiles\H\April1922\ Scan22 | |
| Date | 13th April 1922 | |
| R.R. 235A (100 T) (S.H. 798, 10-12-20) G.{Mr Griffiths - Chief Accountant / Mr Gnapp} 2947 To EFC. from E.{Mr Elliott - Chief Engineer} c. to C.I. Wor.{Arthur Wormald - General Works Manager} c. to By.{R.W. Bailey - Chief Engineer} Hs.{Lord Ernest Hives - Chair} ORIGINAL E4/M13.4.22. 3 GOSHAWK II IGNITION X4354 In reply to your report EFC1/T27.3.22. we should like to know on what your curve of advance required by the engine is based as it differs somewhat from the average advance obtained from the results given in Mr. Hives report Hs{Lord Ernest Hives - Chair}9/LG28421. Both of these curves of engine advance are shewn on drawing Lec 1550 which we send you herewith. With regard to the Goshawk governor Mr. Royce has instructed both verbally and in writing that it should be arranged not to come into operation until 500 r.p.m. on the engine and that the first advance was to be obtained by hand. The governor ratio should accordingly have been modified to comply with these conditions when it would have been found to give a curve of advance practically equivalent to your curve marked II. On the drawing Lec 1550 we shew the governor ratio made 2 to 1 giving a cam advance of 15°. The curve obtained is also given, and the light line underneath marked II is the curve obtained at Derby for the reduced weights with reduced travel. The angular position of the weights and their travel remains unaltered from the original on Lec 1550. Would you kindly pass this drawing to Mr. Bailey so that the modification to the ratio can be tried and would you please let us know if the curve of engine advance marked "A" has been finally authorised by Mr. Hives. E.{Mr Elliott - Chief Engineer} | ||