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).
Notes on shell noise, pipe vibration, silencers, and observations on Cadillac's straight-eight engine and electrical components.
| Identifier | ExFiles\Box 173\1\ img282 | |
| Date | 12th February 1934 | |
| -4- He/Rm.{William Robotham - Chief Engineer}5/WA.{Mr Wallis}12.2.34. Cont'd.{John DeLooze - Company Secretary} (5) They too are troubled with "Shell Noise". They find it is reduced if they use the largest practical diameter of pipe from the manifold to the silencer, on the 12 this is 2 1/2" O.D. and .062" thick. (6) They think one reason why we may have failed to get away without a front expansion box is pipe vibration. They find flexible mountings a very variable amount and frequently have to clamp certain of the pipe sections very rigidly to eliminate a vibration that sounds exactly like a boom. They tie the downtake to the engine at the point where it passes the engine foot. (7) Dimensions of the 12 cyl. silencers, which are located under the running boards not that there is a X in the frame, are 4 1/2" diameter x 48" long. The Straight Eight Engine. It is significant that Cadillacs, who have been V engine exponents all their history, are putting a straight eight in their new model. Electrical. Cadillacs. Coils. They use two coils and one distributor head for the 12 & 16 cylinders. Each coil takes care of one bank, there are two contact breakers. Distributors. They have 12 & 16 cylinder units. They had considerable trouble with electrical breakdown with the black material but now use a rough looking red compositions known as XM1000 which is O.K. | ||