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).
List of proposed engineering changes and improvements to various engine and chassis components.
| Identifier | ExFiles\Box 103\3\ scan0009 | |
| Date | 18th December 1930 guessed | |
| (2) (d) Cast iron head with 6 separate inlet ports for better distribution and suitable for twin carburetters, larger valves, and much better passages, (and permits of double ignition at any time without much change.) (e) Stroke can be increased from 4.5 to 5" = 10%., which allows for 3 to 4 cwt. in complete car, or more than half the improvement of from 3 to 3.250 increase in bore. (f) Increased crankshaft sizes and balance weights mentioned. This is necessary for the increased stroke and for other reasons, and will considerably reduce the trouble from flywheel whirl or crankchamber deflection. (g) Crankchamber much stiffer due to webs and box. girder edge. (h) Less copper pipe and unions, and lockings, etc. (i) Plain bearings for half time wheels, less cost and more silent, and facilitates machining. (j) More oil in crankchamber with equal road clearance. (k) G.{Mr Griffiths - Chief Accountant / Mr Gnapp} of G.{Mr Griffiths - Chief Accountant / Mr Gnapp} of flywheel near centre of main bearing and with stiffer journals and pins; will not whirl in range of useful speeds - i.e. OK. up to 4000 RPM., but we are not sure about master period. (l) Longer con. rods, but there will still be low speed torque reaction vibration, and over-running vibration, but these are being minimised by the soft engine mounting - diamond shape. (m) The gearbox is to be redesigned for epicyclic double top and 3 speed box with silent 2nd., also by jaw clutches. (n) Steering - the cage for the nut is not to be deleted it serves a double purpose - (1) self fitting alignment, (2) allows for inevitable spring of shaft in box under heavy shunting loads, (3) less liability of slack to develop in nut because of (1) and (2), and as we have no means of curing slack we ought to do all possible to prevent it developing. (o) The oil filter is accessible from side of car. (p) Simple cast 3 branch exhaust manifold. R.{Sir Henry Royce} | ||