With a diagram proposing a quieter exhaust design for the SS & 20HP cars.
| Identifier | WestWitteringFiles\T\January1929-February1929\ Scan030 | |
| Date | 17th January 1929 | |
| HS. {Lord Ernest Hives - Chair} E. {Mr Elliott - Chief Engineer} DA. {Bernard Day - Chassis Design} BY. {R.W. Bailey - Chief Engineer} FROM R. {Sir Henry Royce} (At Le Canadel(Henry Royce's French residence).) ORIGINAL SECRET R1/M17.1.29: REC'D AT WW. 21. 1. 29. C. to BJ. WOR. {Arthur Wormald - General Works Manager} SG. {Arthur F. Sidgreaves - MD} PN. {Mr Northey} CWB. SS. {S. Smith} & 20HP. CAR EXHAUSTS. X7230 X5230 Following up the idea already given, it would seem that for an easily quietened exhaust we ought to avoid long straight through pipe by breaking the length by an expansion chamber. The old Silver Ghost(1907 40/50 historic RAC 15,000 miles trial) was good, the 20HP. not so good, and original SS. {S. Smith} bad. Therefore make new SS. {S. Smith} and 20HP. in 3 sections as already suggested - i.e. expansion or damping chamber at bottom of front section, and in the middle of horizontal - i.e. side-step horizontal. E. {Mr Elliott - Chief Engineer} and DA. {Bernard Day - Chassis Design} will try to find simple practical treatment of design. I suggest large capacity may not be needed, but a change of gas speed to destroy energy and prevent surging periods. R. {Sir Henry Royce} Diagram Labels: Elevation. Slide. Fix. Plan Slide. Fix. Fix. Slide. Elevation. Slide. Fix. | ||
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).