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 features including crankcase material, dampers, and cylinder angle.
| Identifier | ExFiles\Box 127\1\ scan0169 | |
| Date | 26th January 1934 guessed | |
| -2- done by machine, in assembling nuts run down by electri-cally driven clutch operated spanners, final tightening done in normal manner. On design I got the following :- Crank Case Material. On the cheap 1800 chassis they are using an alum crank case. On the De Luxe 12 cyl 4300 dollar job a cast iron crank case and cyl block in one. This is because they have found the latter gives the best result for ultimate smooth-ness, with this particular design. The crank has four main bearings only. They say the engine becomes too long if they use any more and still retain reasonable area for their side by side connecting rods. Every one seems sold on side by side connecting rods for simplicity and efficiency. Crank Damper. They too are using the inertia element fixed to the nose of the crankshaft with rubber. In their case the rubber is just vulcanised onto the hub and the flywheel by a new process of which I am trying to obtain particulars. The damper on the 8 is nice and accessible outside the crankcase. They say that the rubber gives them the right rating but has not quite enough internal damping and so they put in a little dry friction by means of pelical springs in parallel with the rubber drive. They say this is the most consistent damper they have ever had. Angle between Cyls. They admit that they used the odd angle between the cyls because they thought it might influence torsional periods but that they now know better. They claim that the combustion chamber and valve design on this unit is very efficient and that they have run up to 130 B.M.E.P. on experimental units. They are selling 6-1 c/r standard on the light eight. We go to the proving ground tomorrow. HS{Lord Ernest Hives - Chair}/sm | ||