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 modifications and material choices for the 'U' Series - 25HP silencer.
| Identifier | ExFiles\Box 179\1\ img033 | |
| Date | 20th October 1931 | |
| P. FROM TA/EV.{Ivan Evernden - coachwork} C. to F.W. HS.{Lord Ernest Hives - Chair} LA{L. A. Archer}/EV{Ivan Evernden - coachwork}/3/420.10.31. K5520. SILENCER FOR 'U' SERIES - 25HP. H.{Arthur M. Hanbury - Head Complaints} has agreed to the use of the P. 2. silencer for the short chassis as suggested and tested by yourselves for 'U' series 25HP. He does however suggest that the riveting of the diaphragms and external fittings might be replaced by spot welding as suggested on our silencer scheme N. scheme 3237., (and shewn on all our previous N. schemes) to cheapen the production. We send herewith N. scheme 3357 showing this exhaust silencer in position in the chassis, and indications of how it can be supported. We are not sure whether you need the front expansion box as you have not reported on this. If this is not used the drawbar for the pipe must be fitted. The swan neck and fishtall already sent you and illustrated on N. sch. 3285. should be used. Also unless you have found it to be unsatisfactory the pipe from the exhaust silencer should be welded in instead of being an iron casting riveted on. Although we use the P. 2. silencer we do not think we should use the sandwiched asbestos heat shield, but would like to continue with the plain sheet steel one as shewn on N. scheme 3237. As a result of an exam: of the broken manifold it is concluded that the fractures are due to contraction of the casting, and not in any way connected with the pipe supporting stays. We have shewn therefore the stays and sliding joints as originally designed. TA/EV.{Ivan Evernden - coachwork} | ||