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).
Letter discussing modifications and performance of vaporizer pipes and pilot jets, including issues with cold starts and smoke.
| Identifier | ExFiles\Box 74\2\ scan0050 | |
| Date | 15th November 1921 | |
| CC Mr. Belnap Mr. Beaver Mr. Nadin X4387 Oy3 - G 151121 Nov. 15, 1921 Mr. Claude Johnson, Managing Director, Rolls-Royce Ltd., London, England. Copy to Mr. Hives. Dear Sir:- Re: Vaporizer Pipes and Pilot Jet On Oct. 22 we cabled, attention Mr. Hives, as follows: "No. 134, Hives - Referring your telegram 347, now have made 12 vaporizer pipes and thoroughly tested small pilot jet on induction pipe. Results uniformly good. Cold starting seems perfect after modifying jet opening. Satisfied results best so far, writing." We have waited for an opportunity to gain a little more experience before writing. Vaporizer Pipes: First with regard to the vaporizer pipes, prints XA-1206/7, A-1357, A-439 and A-440 show present arrangement of collectors, spigotted central with the inlet opening and boilers with 1/2" drain pipes. This keeps wet fuel out of the engine to a remarkable extent, almost incredible after our experience over here with engines which were constantly "wet" from unburnt fuel. We collect anything up to a pint of fuel in the boilers at each cold start. This boils off after about 3 minutes running very violently and causes a smoky exhaust for a minute or two, this smoke being bluish white kerosene smoke. While this is going on it is possible to set the carburation lever dead weak and have all the signs of overrich running. The inside of the cylinder, however, is not wetted appreciably by this vapor and plugs are not fouled. The smoking period might be considered objectionable, but we figure that it is necessary to place before the owner of the car the two alternatives: | ||