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).
The Vokes-Blanvac exhaust silencer, including an extract from the manufacturer.
| Identifier | ExFiles\Box 152\3\ scan0120 | |
| Date | 19th June 1933 | |
| S/W To Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} from F.{Mr Friese} Copy to Wor.{Arthur Wormald - General Works Manager} X442 F11/JL.19.6.33. VOKES-BLANVAC EXHAUST SILENCER. Do you know anything about the above? If not, would you care to have further information? The following is an extract from C. G.{Mr Griffiths - Chief Accountant / Mr Gnapp} Vokes, Ltd.'s letter to us, and we attach the reports referred to:- "The main features are that it is practically of the straight-through pattern, although of completely original patented design and the back pressure is the lowest of any type in existence, at the same time giving almost any desired degree of silence. Furthermore, in respect of a Sports Car where a certain "note" is desired, this "note" does not increase above a certain number of revolutions. We have pleasure in enclosing you some test reports, and all those carried out so far have resulted in immediate and considerable improvement in engine efficiency such as greater H.P. cooler running engine and an amazingly different silencing effect to what we believe was generally understood to be the best existing silencer." Will you please return the attached reports with your reply. Attachments:- Reports re above. F.{Mr Friese} | ||