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).
Comparison report on Packard's air and exhaust silencers versus the company's own more complex designs.
| Identifier | ExFiles\Box 127\1\ scan0248 | |
| Date | 20th November 1935 | |
| -6- Sft{Mr Swift}/Sctl/BH.20.11.35. AIR SILENCER. The air silencer of the Packard appears to be a proprietary article, simple in construction and capable of being easily placed in position by reason if its one piece fixing. As against this, our own manufactured air silencer, whilst having a certain dignity is complicated and expensive, the brackets alone which are attached to the cylinder for fastening to the carburetter, costing, in material and time probably as much as the complete Packard Air Silencer. Further it must be borne in mind that extra tools and time will be required to set the faces of the carburetters in the ¢ correct plane so as to avoid distortion and obtain satisfactory joints. This job gives us again an opportunity to repeat what has been said before, that it is incomprehensible how the research department and others can foster such production as these, and yet criticise us on the amount of time required for hand work. EXHAUST SILENCERS. All the superlatives in the language would not be sufficient to describe the finished exhaust system of the Rolls-Royce when comparing it with the Packard Silencer. The American silencer consists of one chamber only at the rear, with a simple pipe attached at the front end of chamber, and a much simpler pipe at the other end acting as the outlet, bent in the swan neck fashion. At the front end of the main silencer there is a bore. A flange appears to be fitted over this bore and welded, forming a cup into which the end of the pipe is thrust. The cup or socket is saw-cut, so that the clip when placed over it, with the pipe in position, can be tightened up and fixed to the pipe. We presume that the other end is flanged over to take the oval pressing which forms the joint flange, it is attached to the exhaust pipe on the engine by two set screws. An attachment very different from our spherical joints and bedded flanges. The swan-neck pipe emerges from the other end of the chamber, and is attached in the simplest possible way. | ||