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).
Crankshaft calculations including stiffness and inertia for an 8-cylinder Alfa-Romeo engine.
| Identifier | ExFiles\Box 124\5\ scan0126 | |
| Date | 5th January 1934 | |
| X 4482 To E.{Mr Elliott - Chief Engineer} from Hs{Lord Ernest Hives - Chair}/Gry.{Shadwell Grylls} c. to Rg.{Mr Rowledge} Hs{Lord Ernest Hives - Chair}/Gry.{Shadwell Grylls}19/KW5.1.34. 8 Cylinder Alpha-Romeo. ----------------------- We have carried out a few calculations on the crankshaft of this engine. Assumption had to be made for the inertia of con. rods and pistons. The inaccuracies will not be great. Stiffness of Crankshaft 48,500 lbs.ft./radian. Inertia of Crankshaft excluding gears. 217 lbs. in2. Inertia of gears. 222 lbs. in2. Inertia of con. rods and pistons (approx.) 41 lbs. in2. As we do not know the mode of vibration of this crankshaft due to the large inertia in the middle, we cannot calculate the critical speed, but are trying to get this figure from the owner of the car. Hs{Lord Ernest Hives - Chair}/H.Grylls. | ||