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).
Report discussing piston seizure and scoring issues attributed to misuse of the starter carburetter, proposing a modification.
| Identifier | ExFiles\Box 13\3\ 03-page163 | |
| Date | 19th December 1929 | |
| Pt.2/PH/19-12-29 47280 By.{R.W. Bailey - Chief Engineer} Derby. (Copy to Hm{Capt. W. Hallam - Head Repairs},Derby, Whr{Mr Wheeler},London, Hs.{Lord Ernest Hives - Chair} Derby.) Some time ago Chassis 33-CL - Chirnside, seized up unaccountably within a mile of leaving the coach-builders where it was kept standing for some time. This is now ancient history, but I am referring to it because I diagnosed the trouble being due to the fact that the owner or driver or some other person had left the engine running for a prolonged period upon the starter carburetter so that the pistons were probably on the verge of seizing when the main carburetter was brought into action and the car probably accellerated from a standstill. A second case has now arisen almost on all fours with this one,- in this instance Chassis 127-WR owned by Mrs. E.G.H.Carter was recently brought to Dalgetys' Service Depot with very loud piston knocks, about which owner complained. Upon dismantling, the pistons were found to be scored, though not so badly as those in the case of 33-CL, and after filing and peaning were capable of being refitted to the cylinders, whereas in the former case it was considered necessary to fit a new set of pistons. While admitting that the starter carburetter is a great convenience, and in fact a necessity on an engine of this size, it seems that something will have to be done to make it's use possible and it's abuse impossible,- in other words, to make it 'fool proof', and the only way that I can see in which this might be carried out is to incorporate in the starter carburetter itself an inlet for oil as well as an inlet for petrol. The difficulties in connection with this would appear to be that the oil arriving at the starter carburetter under pressure might entirely overcome the ingress of petrol unless the oil supply was provided with an adjustable needle valve. In any case, the adjustable needle valve on the existing petrol supply, and also the adjustable needle valve on the suggested oil supply would still both be | ||