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).
Phantom II exhaust modifications, performance testing, and the failure of aluminium components due to heat.
| Identifier | ExFiles\Box 11\3\ 03-page184 | |
| Date | 12th July 1930 | |
| To: Hs.{Lord Ernest Hives - Chair} From G.W.H. [Handwritten Note] Rm{William Robotham - Chief Engineer} / See my note to G.W.H Hôtel de France, Châteauroux, Indre. 12/7/30. We have returned here this evening with the exhaust fitted up as follows:- Phantom II rear silencer, straight through pipe from manifold to rear silencer, the straight through pipe being approx. 2.625" dia. One feature I noticed with this arrangement was the exhaust boom at 60 M.P.H. driving is not so pronounced by 20%, but cannot detect any difference on the retard. The speed of the car is increased by approx. 4 M.P.H. I may be able to confirm this later on the Monthléry track. Re this matter, I have been waiting information from "Hk{Col. T. Harker - Sales}" re times, price, conditions etc., of the track, which I have now received. I should have called on my way down, but the atmosphere temperature had dropped to 21°C, therefore I did not think the tests would be of any value. The tests I have already carried out and reported to you have been taken on a five mile stretch the other side from here of Vierzon, taken both ways, an average speed of 80 M.P.H. being maintained. I think this is equal to any track work, as it is practically level, an average of six runs being reported. Re the Silencers. I am at a loss to understand the sending out of aluminium boxes without any alteration, after I have reported the cause of the failures. It has been scheming and work to keep the car running with the failures one after another of the aluminium boxes. The reason of the failures is the hard driving and higher air temperature, with the result that the aluminium has actually melted; previously the cooler atmosphere had been sufficient to prevent this state of affairs. We should, had it been possible, have fitted up the steel front expansion box which | ||