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).
Performance, engine noise and exhaust issues of the 11-AU Open Touring car after a road test.
| Identifier | ExFiles\Box 72\4\ scan0239 | |
| Date | 18th October 1924 | |
| To BJ. From PN.{Mr Northey} Re: 11-AU - Open Touring 40/50 HP. fitted with F.W.B's. As arranged, I am sending this car to be with you at 4.30 this afternoon, in order that you may form an opinion as to the new noises which we are asked to put up with in connection with this model, arising out of the modified exhaust fittings design. I found that the power of this car since it went to Derby, has been greatly improved. Its acceleration is remarkably good. Its speed yesterday with four up, when I was giving a demonstration to Mr. Palethorpe (who requires speed), went up to 74 m.p.h. on the new motor road towards Slough. Undoubtedly the car was still accelerating, but obviously this sort of speed is highly undesirable in such places. I will arrange to check the speedometer at the earliest moment, but have no reason to look upon it with any great suspicion. There is an undue amount of roughness in picking up with this engine at speeds when under 30 m.p.h. This will probably improve with wear, but meanwhile I feel it is excessive. The car generally speaking is giving a very good impression, but Mr. Coates, to whom I gave a trial run, appeared to be more influenced by the exhaust sounds and the apparently uneven firing of the engine, than anything else about the car. It does not, of course, follow that the cylinders are actually firing unevenly, because the sound of them is of that nature, having regard to the fact that with the present arrangement of exhaust fittings, certain forward cylinders are altogether nearer the exhaust pipe than those at the rear, but I feel we are distinctly giving up part of our life's blood in allowing this arrangement with its disabilities as demonstrated on this car, to become standard. (Sgd) PN.{Mr Northey} | ||