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).
Engine design choices, including crankshaft balance, ignition, governors, and connecting rod lengths.
| Identifier | ExFiles\Box 61b\4\ scan0178 | |
| Date | 29th January 1931 | |
| E.{Mr Elliott - Chief Engineer} HS.{Lord Ernest Hives - Chair} FROM R.{Sir Henry Royce} (At Le CanadelHenry Royce's French residence.) C. to SG.{Arthur F. Sidgreaves - MD} WOR.{Arthur Wormald - General Works Manager} BY.{R.W. Bailey - Chief Engineer} C. to HY.{Tom Haldenby - Plant Engineer} RHC.{R. H. Coverley - Production Engineer} JAPAN 3. ENGINE Lec. 2853 X6105 R4/M29.1.31. X. 5770. X. 5030. X. 6105. This seems quite right. The only additional suggestions I can make at the moment are that the crank pins shall be bored rather larger for lightness, and arrangements on crank for 4 balance weights equal to about half total out of balance. If we arrange to go straight on with double ignition (HS.{Lord Ernest Hives - Chair} and Mr. Minchin say it would be appreciated) I should like to see double head for this and P. 2. It would be better with a single governer because of synchronism and our double governer is so very efficient that it might control two, but there are arguments for 2 governers, and if we could get them very simple to make the general design might be easier. I imagine central spur driving 2 heads in the same direction, thus - E.{Mr Elliott - Chief Engineer} will try what suits the drawings best. Re. CON. ROD LENGTHS. After much discussion there seems no very definite wish for long rods, but I understand that probably the longer rods are still worth their cost, because although they only help the small percentage we originally estimated several years ago they do reduce several troubles i.e. say 1/20 less maximum bearing pressure 1/10 less flywheel needed, or 1/20 less balance weights, and 1/10 less speed variation and over-running forces. Possibly they are needed to get the camshaft wheel below the top face of crankchamber. In short I agree to whatever suits the general design best, but some where between 1.8 and 2. Piston, skirt clearance, and possibly oil consumption all favour long rods. R.{Sir Henry Royce} | ||