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).
Investigation into 20/25 carburetter flooding, potentially caused by engine oscillation from rubber mountings.
| Identifier | ExFiles\Box 102\1\ scan0290 | |
| Date | 29th May 1935 | |
| X508 W/S. To C. from E.{Mr Elliott - Chief Engineer} c.c. Sg.{Arthur F. Sidgreaves - MD} Wor.{Arthur Wormald - General Works Manager} Hs.{Lord Ernest Hives - Chair} Ey. Mx.{John H Maddocks - Chief Proving Officer} T/Psn. E.1/HP.29.5.35. re 20/25 Carburetter Flooding. Confirming conversation with you yesterday re the above, it is very important that we should be enabled to make a close inspection of these carburetters that have given trouble. It is not sufficient for the service people to have seen them, as we wish to examine them in respect to particular features of design. Since you told me about Major Monro's car and the association of flooding with the car being on a downward grade it has occurred to me that there may be some other explanation of this trouble arising from the rubber mounting of the engine. We know that with this rubber mounting the engine does occasionally, due to missing, oscillate very violently at times, and this has the effect of jerking the carburetter somewhat forcibly up and down. Under these conditions the equilibrium of the float is considerably disturbed, in fact it may be jerked from one extreme to the other, and may jam in the open position. I think, therefore, we will make tests to find out whether we can reproduce this. We have had trouble on SpectreCodename for Phantom III 1 with the carburetters flooding due to engine movement, but in this case the floats are mounted with their pivots parallel to the axis of the engine, and the disturbance amounts to a rocking motion. Could you kindly say if it would be possible to get hold of Major Monro's carburetter. With the nose of the car downwards and the needle inclined to lean forward, these are the worst conditions which might lead to the possibility of jamming in the full open position, and which we will attempt to re-produce. | ||