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).
Comparison of piston performance based on manufacturing method (forged vs. pressed) and material type (RR.59 vs. Y alloy).
| Identifier | ExFiles\Box 148\3\ scan0068 | |
| Date | 12th March 1931 | |
| Hs.{Lord Ernest Hives - Chair} X4004 BY3/G.12.3.31. PISTONS - RE R.R.59 MATERIAL. ------------------------------- We have heard through Mr. Devereux that Mr. Fedden finds a definite improvement when comparing :- 1/- Pistons in RR.59 material with 2/- Pistons in Y. alloy. He, however, states that there is a marked difference in RR.59 material between a/- Pistons which are really forged i.e. by our old method, working from a blank, with considerable forging put into them purposely. b/- Pressed pistons as produced by Messrs. Turton Platts. In this instance the pistons are produced by hydraulic pressure, and a general slow flow is produced, starting from a blank, which has been extruded. In view of the foregoing therefore, which I can easily get confirmed or otherwise, but I see no reason for doubting the statements, it is very important that we should mix our pistons on the two development engines, so that on both engines we have pistons of both types. We are told that Mr. Fedden has completed two standard type tests, apparently with mixed pistons of RR.59 material, and done 400 hours running on single cylinder units. In each case either of the RR.59 are better than similar tests carried out on 'Y' alloy, mainly in the direction of reduced wear and tear, particularly in the ring grooves, and that the forged piston shows in the same direction a distinct reduction of wear over the pressed piston. BY.{R.W. Bailey - Chief Engineer} By [Stamp: RECEIVED HS{Lord Ernest Hives - Chair} 1931 MAR] | ||