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).
Modifications to the Phantom III exhaust system to reduce weight and cost.
| Identifier | ExFiles\Box 93\1\ scan0051 | |
| Date | 12th November 1936 | |
| 32D COPY. 12/11/36. Hs.{Lord Ernest Hives - Chair} c. to By.{R.W. Bailey - Chief Engineer} c. to E.{Mr Elliott - Chief Engineer} PHANTOM III EXHAUST SYSTEM. We have now concluded our experiments on the above exhaust system with a fair amount of success in our efforts to reduce both the weight and cost. We have reduced the weight by, approximately, 30 lbs; the straight through system employed in the rear silencer is simple and easy to manufacture, and there is a gain of 5 BHP at 4,000 RPM. We also propose to substitute "Aluminized" mild steel parts for staybrite and nickel plated mild steel lagging covers in place of the stainless steel ones. We also suggest that the lagging covers be spot welded into position, thus dispensing with the use of expensive Jubilee clips. These modifications we think will result in a considerable saving per car. Summarized the modifications are as follows:- (1) Downtake pipes E.86818/9 to be made in 14 SWG mild steel "Aluminized". (2) Delete front expansion box E.86602 and fit "Trouser" piece as shown in attached sketch. (3) Intermediate pipe E.88000 to be made in 16 SWG mild steel "Aluminized". (4) Rear silencer assembly E.86539 to be discontinued and new silencer made as per attached sketch. (5) Tail pipe E.88296 to be discontinued and new tail pipe made as per attached sketch. (6) Tail pipe to be mounted on rubber as in Scheme LeC.5340. (7) All lagging covers to be made in 24 SWG mild steel nickel plated and spot welded in position, Jubilee clips to be deleted as far as possible. | ||