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).
Design and material choices for a Private Venture aero engine.
| Identifier | ExFiles\Box 179b\1\ img245 | |
| Date | 23th December 1932 | |
| RO{C. C. Rose - Export Manager} ) FROM R.{Sir Henry Royce} RY ) HS.{Lord Ernest Hives - Chair} ) C to SG.{Arthur F. Sidgreaves - MD} WGE. H.{Arthur M. Hanbury - Head Complaints} R1/M20.12.32. Sent off 23. 12. 32. AERO ENGINES. X23174. PRIVATE VENTURE ENGINE. The drawings I have received of the P. V.{VIENNA} engine look very hopeful for a good design, and the photographs of the mock up make the design look clean. I am pleased to see that you have shewn the articulated rods for this engine. The fork and blade rod does not, in the face of past experience and the desired use of Kelmit, appear worth working on except to improve those already made, or in hand. I am also pleased to see that you are making an effort with another type of piston, as for some time I have been disappointed with the amount of surface on our pistons to carry the load due to the angularity of the con. rods, especially as we use con. rods of very short proportions so as to reduce the weight of the engine. A point that has been worrying me for some time is whether we are making sufficiently rapid progress with the production of hardened liners. I understand the situation at the moment is that we can give hardened crankshafts, but these are not particularly desired by the Air Ministry, although personally I think they should be of wonderful to an engine, especially if fitted with Kelmit bearings. I notice in Mr. Rubbra's report on the Paris Show that the Hispano are using hardened liners, but not hardened shafts. Now I have thought for a very long time that the hardened liner is more important than the hardened shaft because it should reduce the risk of a piston seizure, and also reduce the wear of piston rings. It may very materially affect the time in which it would be safe to get away starting cold. It might also enable us to run with less oil consumption and more effective double scraper rings. Anyway, if I were a buyer, I would rather buy an engine with hard liners than with a hard crankshaft. Naturally I should prefer them both hardened. (1) | ||