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).
Recommendations for rectifying piston rattles by fitting extra rings and considering lubrication oil types.
| Identifier | ExFiles\Box 171\3\ img037 | |
| Date | 6th May 1920 guessed | |
| -2- Contd. RECOMMENDATIONS. Upon consideration of the above facts the Exptl. Dept. recommend that the present pistons should have the extra rings fitted as soon as ever possible. Our reasons for recommend-ing this are as follows:- In placing a ring high up on the piston we are only reverting to a practice which was used successfully on all our pre-war cast iron pistons. All R.R. Cars on the road (previous to the war) had rings high up. On the present production cars which are being run on Price's oil, although there are no cases of piston rattles, there are distinct signs of carbon marking the top band of the piston. The cause of the piston rattles is quite clear. There is only one possible means of preventing the cause of it i.e. to fit a ring to the top band of the piston. We think it will be disastrous to R.R. if, when we have seen a fault on a car and can see a clear cause for the fault, and have a straightforward means of overcoming that fault, we do not take immediate steps to overcome it. The only excuse we have for syging that the present cars will not have piston rattles the same as 2EX. Car, is the fact that 2EX. Car was run on Castrol Oil, yet at the same time we have to admit that Castrol oil is the best lubricant we know of and if one of our cars was going to take part in an arduous endurance test there is not much doubt that Castrol oil would be used. We believe a part of the niceness of 2EX. Car after running 10,000 miles is due to the fact that it has been lubricated with Castrol oil throughout. Apart from overcoming piston rattles, we need the extra rings to improve gas tightness of the pistons. HS.{Lord Ernest Hives - Chair} | ||