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 and engine firing orders, comparing a Phantom II engine with a 60 Vee 6250 cc model.
Identifier | ExFiles\Box 138\1\ scan0015 | |
Date | 24th February 1932 | |
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}S/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 350 engine would be a negligible improvement. Lincoln employ an unusual firing order namely :- 1 → 5 → 3 → 6 → 2 → 4 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. | ||