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).
Inter-office correspondence discussing engine pre-ignition issues related to heated induction pipes and findings from an engine strip-down.
| Identifier | ExFiles\Box 75\2\ scan0221 | |
| Date | 27th April 1921 | |
| H.R.A.-25-5m.-9-27-20 40233 X2758 INTER-OFFICE CORRESPONDENCE ROLLS-ROYCE OF AMERICA, INC. SPRINGFIELD, MASS. Oy3 - G 27421 April 27, 1921 Dear Hives: Re: Induction Pipes Replying to your questions regarding heated induction pipes (Hs{Lord Ernest Hives - Chair}3/LG11.4.21), we have the idea that the present pipes with 1" through pipe are on the "mild" side in the application of heat. They do, however, appear to cure the phenomenon of "loading up" to such a great extent that the customer is not likely to strike it. A slight remaining tendency to miss on opening up has been cured by the pin in the throttle, of which you sent us sketches, and our slow speed hill climbing has been improved by this pin in such a large number of instances that there is no doubt in our minds as to the efficacy of the cure. (Our only wonder is how on earth the cure was discovered). We are going to try out our scheme with the additions you propose, namely taking the blast from Nos. 1 and 6 alone as far as possible, to get a slower surge, and see whether we get any recurrence of pre-ignitions. It is pre-ignitions that we are afraid of, and it is pre-ignitions that we undoubtedly got, with the jacket at the Tee, both the full jacket and the "saddle" jacket. The symptoms were that in slow full throttle running on the brake or up hill at 15 m.p.h. the engine would give a distinct kick back, which got worse as one continued when running with battery ignition or battery and magneto. This occurred with advanced or retarded spark, but was worse with advanced spark. On taking the engine down, we found certain inlet bends absolutely dry, the porcelain of the plugs absolutely clean, but the battery plugs covered with a shiny iridescent coat (as though they had been "fired" in a stove) and a yellow coating on the exhaust valves, which, when analyzed, proved to be Chromium Oxide. We are told that this oxide would not appear below temperatures in the neighborhood of 2000° F.{Mr Friese} | ||