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).
Intermittent misfiring on 'Silver Ghost' chassis related to the Autovac connection.
| Identifier | ExFiles\Box 40\4\ Scan088 | |
| Date | 22th May 1925 | |
| 13579 H2/TB/22.5.25. S/W. Hs.{Lord Ernest Hives - Chair} from H.{Arthur M. Hanbury - Head Complaints} Re:- Effect of Autovac connection on Induction Pipe conditions "Silver Ghost" type Chassis. You are probably aware that from time to time we have cases of intermittent misfiring, causing an unpleasant break in the steady running at slow speeds on these engines. Last week we had a case, namely, that of Chassis 41-TM. belonging to Col. C. Gerard, in which he complained bitterly of this since having his Front wheel Brakes and Autovac System fitted. He said that, when running along slowly, say, at 10 m.p.h. at intervals from 5 to 10 minutes, he would get a most palpable misfire causing the car to bucket, that is to say, exposing the transmission slackness. He had established to his own satisfaction that this coincided with the functioning of the autovac mechanism. I endeavoured to maintain that this was a pure coincidence, and that the misfiring must be sought for in other directions. Henning and I did, indeed, do everything we know to trace and cure the misfiring, and finally communicated with Br.{T. E. Bellringer - Repair Manager} at N., where the car had been some days previously for the same reason, and where the valves had been had out. Br.{T. E. Bellringer - Repair Manager} gave it as his opinion that Col. Gerard was perfectly right, and that the conditions in the induction pipe, presumably in the neighbourhood of No. 6 cylinder are upset at the moment of the functioning of the autovac, and that when this functioning coincides with No.6., a miss is caused. This was news to me, and the matter is now being put to you for your suggestion as to a cure by the desire of CJ., Col. Gerard having written to know what we are going to do about it. Will you kindly let us have your suggestions as soon as possible. H.{Arthur M. Hanbury - Head Complaints} | ||