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 considerations, including component variations and weight analysis.
| Identifier | ExFiles\Box 88\3\ scan0172 | |
| Date | 7th August 1935 | |
| -2- Hs{Lord Ernest Hives - Chair}/Smth.9/KW.7.8.35. (2) Effect of Stroke & Bore Variation. The attached figure (Hs.{Lord Ernest Hives - Chair}2077) shows the effect on weight of varying (a) the stroke, and (b) the bore of a 3.5 x 4.5 6-cyl. engine. The effect is practically the same for both types of construction. These results were obtained by analysing the effect of stroke and bore variations on each of the principal components. (3) Side Valves versus Overhead Valves. We think that the extra metal in the block of a side valve engine will about balance that in the head of an overhead valve. For engines made of the same materials the overhead valve type will be 5 to 10 lbs. heavier owing to the weight of the rocker shaft assembly and push rods. (4) Weight of an 8-cyl. 3.125 x 4.500 alum. constr. engine. This would be 370 lbs. or 420 lbs. with dynamo and starter motor, if the spaces between the cylinder bores were similar to those on the 3.500 bore Bentley. The length of the block would be 31.5". Wraith will weigh 20-30 lbs. more than this owing to its greater length. Hs{Lord Ernest Hives - Chair}/Smth. | ||