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).
Torsional vibrations comparing the 6th order vibration on a Phantom II engine with a 60 Vee 6250 cc engine.
| Identifier | ExFiles\Box 43\4\ Scan337 | |
| Date | 24th February 1932 | |
| 84024. x634. R.{Sir Henry Royce} From Hs{Lord Ernest Hives - Chair}/Gry.{Shadwell Grylls} c. to E.{Mr Elliott - Chief Engineer} c. to Rs.{Sir Henry Royce's Secretary} Hs{Lord Ernest Hives - Chair}/Gry.{Shadwell Grylls}3/MA.24. 2. 32. TORSIONAL VIBRATIONS. ------------------------ E.{Mr Elliott - Chief Engineer} has asked for a prediction of the relative severity of the 6th. order vibration on P.II and a 60 Vee 6250 cc. engine. That is of course a comparison of the Phantom half period and the 12 cylinder top period. Assuming the same indicator diagram in each case the period on the 12 cylinder should be 5/6 of the magnitude of that on P.II. This is true for any firing order of the Vee engine. A 650 engine would be a negligible improvement. Lincoln employ an unusual firing order namely :- 1 5 3 6 2 4 5 3 6 2 4 1 For the 6th. order vibration this has no effect on the magnitude of the vibration. It is true to say that the magnitude of the nth order vibration of an n throw crankshaft engine is independent of the firing order. Other vibrations are however affected. Hs{Lord Ernest Hives - Chair}/H.Grylls. | ||