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).
Specification memo detailing modifications for the Spectre II car's exhaust silencer.
| Identifier | ExFiles\Box 91\3\ scan0098 | |
| Date | 16th September 1935 | |
| X300a (2) To RHC.{R. H. Coverley - Production Engineer} Hs{Lord Ernest Hives - Chair}/Wym.{G. Harold Whyman - Experimental Manager}15/KW.16.9.35. SpectreCodename for Phantom III Exhaust Silencer. Whilst SpectreCodename for Phantom III II car is in the fitting shop we would like you to modify the exhaust system rear silencer to our latest scheme, which we think will be the final one. The complete specification is as follows :- Complete silencer assembly to E.86539 with the following modifications. (a) 1.00" to be sawn off small end of cone E.86525 increasing dia. from 1.500" to 1.750". (b) Increase number of .312" dia. holes from 42 to 56. (c) Incorporate Mod. LeC.4666 to overcome gas restriction. (d) Increase number of .500" dia. holes in baffle E.86514 from 18 to 22. (e) Increase number of .562" dia. holes in baffle E.86515 from 16 to 18 (f) Baffles E.86514/5, E.87335, and E.86512, should be made with ends of baffles curled over as per LeC.3759 to cure crackling (g) Blank end E.86501 to be deleted leaving pipe E.86531 a straight through pipe. (h) 2 further rows of holes in both top hats E.86526/7 increasing number from 60 to 84. (i) Rear silencer to be lagged a distance of 2 ft. 4 ins. from front end with 3/8" dia. asbestos rope. We would also like you to fit a cut out plate on the intermediate pipe similar to the one on SpectreCodename for Phantom III I so that the car can be tried on the track with open and closed exhaust. Hs{Lord Ernest Hives - Chair}/G.H.Whyman. | ||