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).
Two experiments with beneficial results on the 'flywheel period' vibrations on a 25-HP engine.
| Identifier | WestWitteringFiles\V\December1930-February1931\ Scan015 | |
| Date | 8th December 1930 | |
| To R.{Sir Henry Royce} From Hs{Lord Ernest Hives - Chair}/GR.{George Ratcliffe} c. to Ss.{S. Smith} WOR.{Arthur Wormald - General Works Manager} c. to Ds. E.{Mr Elliott - Chief Engineer} c. to By.{R.W. Bailey - Chief Engineer} ORIGINAL Hs{Lord Ernest Hives - Chair}/GR.{George Ratcliffe}1/MJ.8.12.30. X634. VIBRATIONS ON 25-HP. Continuing our report Hs{Lord Ernest Hives - Chair}/GR{George Ratcliffe}/MJ.21.11.30. we have done two experiments with beneficial results on the "flywheel period". (1) The new W.W. flywheel on C.7 unit raised the maximum amplitude of the period from 42 M.P.H. in third (3150 R.P.M.) to 47 M.P.H. or 3520 R.P.M. at which speed the valves were bouncing. Valve bounce commenced at 3400 R.P.M. on the 110° camshaft with standard springs. (2) A white metal tail-bearing on 12-G4 rendered the engine quite smooth up to 4100 R.P.M. (special camshaft and springs fitted), apart from a sharply defined period at 2800 R.P.M. (38 M.P.H. in third gear). This period was only noticeable on the over-run. The alteration did not affect the lower speed booms appreciably. We think one possible reason why the new flywheel on 18-G4. was an improvement when our lightened flywheel had not been, is due to the new W.W. flywheel having a very much stiffer back plate. Hs{Lord Ernest Hives - Chair}/M.Grylls. | ||