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).
Piston clap issues and various component breakages in pre-war and post-war cars.
| Identifier | ExFiles\Box 16\1\ Scan153 | |
| Date | 14th November 1923 | |
| COPY. E.{Mr Elliott - Chief Engineer} C. BJ. C. Hm.{Capt. W. Hallam - Head Repairs} BY11-P14.11.23. PRE-WAR PISTONS & PISTON RING CLAPS. Referring to E1/M121123, written to BJ. in connection with our proposal to overcome piston clap troubles by the use of narrow rings on cast iron pistons, spaced and proportioned like our present piston rings on aluminium pistons, there were definite reasons why I urged the use of the cast iron pistons, and before we commit ourselves I would like the full facts of the case put before R.{Sir Henry Royce} On the post-war cars fitted with aluminium pistons we have had troubles with the following parts :- 1. Top Water Pipe breaking. 2. Bottom Water Pipe breaking, subsequent to a short length of rubber pipe being incorporated in the top water pipe. 3. Extra Oil Connections breaking. 4. The latest development which has come to my notice within the last two or three weeks is, induction pipes breaking. The type of fracture shews that the cause of the trouble is a longitudinal bending moment imposed by the carburetter pipe on the main induction pipe, fracture taking place at the junction between the two. I consider the cause of this trouble is that the carburetter stay pulls against either the forward or rear dowel of the induction pipe according to which end of the cylinder the sliding dowel is arranged; the actual number of breakages which have been brought to my attention within the time specified is five. I intended to write to R.{Sir Henry Royce} pointing out this trouble and make the suggestion that we should slot the hole by which the stay is connected to the carburetter, using a shoulder stud, so that the stay could not be nipped positively to the carburetter, with the addition of a fairly stiff spring which would clamp the two together to permit sliding in a longitudinal direction. (Cont'd.{John DeLooze - Company Secretary}) | ||