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).
Design and testing requirements for a J. 1. exhaust and silencing system.
| Identifier | WestWitteringFiles\V\March1931-September1931\ Scan247 | |
| Date | 5th June 1931 | |
| B/. FROM DA.{Bernard Day - Chassis Design} C. to S/. WCR. HS.{Lord Ernest Hives - Chair} J.{Mr Johnson W.M.} 1. EXHAUST SYSTEM. We send herewith N. schs. 3285/6/7. shewing the exhaust silencing system for J.{Mr Johnson W.M.} 1. The design is based on that for P. 2. which system when fitted to the 25HP. shewed a marked reduction in the loss of power. GENERAL LAYOUT - N. Sch. 3285. We wish to test the system with and without the front expansion box. The manifold pipe is 2" dia. and the swan-neck pipe is increased to 1.5". The latter has the revised supports already sent to you. FRONT EXPANSION BOX - N. Sch. 3286. This follows closely that used on P. 2. except that we wish to avoid the use of lagging if possible by using a thicker gauge of steel for the pipe and box. EXHAUST SILENCER - N. Sch. 3287. The design for the exhaust silencer also follows that of P. 2. closely. It will be necessary to determine experimentally whether the silencer need be so long, and what holes are best for the baffles. To start with we shew the same holes in size and number as on P. 2. The heat shield has no asbestos lagging. Everywhere possible we wish you to try the use of spot welding in the place of riveting, which in some cases appears to us to be very difficult to do, and seems to call for interrupted erection progress. We have provided no drag link to take the rearward thrust on the box as we believe the stiff sheet steel support bracket on the new sheet metal chassis crossmember is capable of taking this load. We wish you to try the system with and without the flexible support to the swan-neck from the 2nd. crossmember, but we think all cars should have the extended fishtail supported from the 1st. crossmember, as so many cars these days have either bodies or aprons to trap the exhaust fumes. DA.{Bernard Day - Chassis Design} | ||