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 unsatisfactory performance of a Zenith carburettor and back axle on a Metallurgique car.
| Identifier | ExFiles\Box 122\1\ scan0001 | |
| Date | 22th November 1910 | |
| 53A (100H) (P 355. 18.8.10) E.P. 7252. 22nd November 1910. Dear C.J., With further reference to the Metallurgique car - the Zenith Carburettor on this car, which was considered to be a good one in the opinion of a lot of people, is exactly what I anticipated it to be, which is not very satisfactory. Firstly, in running slowly, it dribbles petrol all the time, and is, one would think, carefully arranged to allow this dribble to run down the carburettor and waste on the road, instead of doing harm in picking up. Secondly, the carburettor seems to throttle the engine when running fast. This carburettor is of a design in which the petrol jet effectively gets smaller as the speed gets higher, whereas we always believed that the carburettor should get freer for the passage of air as the speed gets higher, and we have, since the earliest time endeavoured to get the passage for the petrol also freer. This is carried out in the most perfect manner we have seen in the Polyrhoe carburettor. Back axle. This was provided with no thrust bearing to take the pressure of the bevel pinion. The wheels are soft, poorly cut, the axle not being very quiet although enclosed in a heavy malleable casting and filled in with thick X1053 | ||