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).
The incompatibility of post-war aluminium pistons with pre-war connecting rods to cure piston ring clap for Chassis 41-NA.
| Identifier | ExFiles\Box 16\1\ Scan152 | |
| Date | 17th November 1923 | |
| C O P Y. - for Hs.{Lord Ernest Hives - Chair} X741 To Bt.{Capt. J. S. Burt - Engineer} from Hm.{Capt. W. Hallam - Head Repairs} C. to BJ. C. to H.{Arthur M. Hanbury - Head Complaints} C. to Py. Hm{Capt. W. Hallam - Head Repairs}/WW4/W17.11.23. Chassis No. 41-NA.{Mr Nadin} - Capt. Philpott. With reference to your memo Bt{Capt. J. S. Burt - Engineer}2/EP{G. Eric Platford - Chief Quality Engineer}/16.11.23, we have to inform you that the decision given in E1/M12.11.23, and referred to in BJ3/H13.11.23, does not settle the question of curing piston ring clap. Post-war aluminium pistons cannot be used with pre-war connecting rods, owing to differences in the length of the pre-war and post-war type connecting rods. Also there is a further objection at the moment: Experiments with post-war pistons on pre-war cars to cure pistons ring claps have not been carried out; such experiments and tests would have to be made before a Standardisation Sheet would be issued. It is of course, obvious that if to cure piston ring claps on pre-war chassis we have to fit post-war pistons and connecting rods, it will be a very much more expensive job, and this is why we are anxious that our previous suggestion to fit post-war type piston rings to pre-war type cast iron pistons should be sanctioned, as the expense of changing over connecting rods would then be avoided. You will, therefore, see that it will not be advisable to write to Capt. Philpott or any other owner who is troubled with piston ring clap, until the whole matter has been definitely settled. Hs.{Lord Ernest Hives - Chair} will be going to West WitteringHenry Royce's home town on Monday next, the 19th inst., and he will take the opportunity to discuss the whole matter with R.{Sir Henry Royce} Hm{Capt. W. Hallam - Head Repairs}/WW. | ||