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).
Log of daily tests conducted on an exhaust system, modifying components and measuring performance improvements.
| Identifier | ExFiles\Box 14\6\ Scan251 | |
| Date | 29th October 1931 | |
| -2- 17.10.31. Cylinder heads and exhaust systems changed back to their respective cars. 18.10.31. Next tests were on 22-EX with Intermediate pipe lagged, Downtake pipe unlagged, and front expansion box unlagged, but reinforced with metal .080" thick round the bottom half (original thickness of box .080") Result 5% improvement. 20.10.31. Top half of box then reinforced similarly making total thickness of box .160" Result - 30% improvement. 23.10.31. Whole of expansion box reinforced with a further .080" thickness of metal making total thickness of box .240" Result - 100% improvement. i.e. as good as standard box lagged. 24.10.31. Downtake pipe re-lagged. This cuts out the swishing noise, and is better than with the pipe unlagged. 25.10.31. Cast Iron expansion box .240" thick fitted. Result. - as good as standard box lagged. 27.10.31. Lagging removed from downtake pipe and pipe original thickness of .104" reinforced with metal .080" thick making total thickness .184" Result - 100% - as good as standard downtake pipe lagged. 29.10.31. Lagging removed from Intermediate pipe and pipe original thickness of .064" reinforced with metal .040" thick making total thickness .104" Result - Better than standard intermediate pipe lagged. We now have an exhaust system with no lagging which is slightly better than standard made up | ||