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).
Programme of changes for pistons and tappets on the Spectre Engine Unit.
| Identifier | ExFiles\Box 4\1\ 01-page246 | |
| Date | 4th February 1935 | |
| To RHC.{R. H. Coverley - Production Engineer} +30D Ha/Rn.{Mr Robinson}12/KW.4.2.35. SpectreCodename for Phantom III Engine Unit. The two major problems on the SpectreCodename for Phantom III engine unit are pistons and tappets. For the tappet job you are making us a camshaft having a reduced base circle and so reducing the velocity. E.{Mr Elliott - Chief Engineer} is also putting some roller tappets in hand. We have the following programme for pistons - (1) Instead of the existing Aerolite pistons being fitted in No. 1 unit as instructed in Ha/Rn.{Mr Robinson}2C/KW.25.1.35, we should like the latest set of Aerolites at present in the Stores, to R.64546 but ground to No. 16 form, to be fitted. (2) We should like the 1/4" and 1/2" longer pistons to be pushed forward to the grinding stage, the final grinding dimensions to be decided when we have run the semi-split pistons to EV.{Ivan Evernden - coachwork}42. In conjunction with these longer pistons it will be necessary to have the longer cylinder liners and the strapped up connecting rods. (3) For the time being we do not want to run any of the lightened cylinder liners. Will you therefore please put these on one side. (4) We have evidence that there are variations in the roundness of the liners fitted in our various engines. For instance, the semi-split pistons to R.64545/6 were noisy in No. 1 unit but silent in No. 3 unit. We should be glad if you would make investigations to see whether the liners remain round after running in the crankcases and also whether they alter in shape when steam is blown through a block. Ha/Rn.{Mr Robinson} | ||