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).
Issues related to faulty carburation and low-grade motor fuels.
| Identifier | ExFiles\Box 50\3\ Scan015 | |
| Date | 24th January 1921 | |
| X4305 Hs. {Lord Ernest Hives - Chair} from EP. {G. Eric Platford - Chief Quality Engineer} C. to R. {Sir Henry Royce} C. to HV. C. to Wd. {Mr Wood / Mr Whitehead} C. to WOr. {Arthur Wormald - General Works Manager} EP {G. Eric Platford - Chief Quality Engineer} 19/F24.1.21. X4305 RE. FAULTY CARBURATION, AND LOW GRADE MOTOR FUELS. With reference to R's report R7/G13.1.21, we certainly can confirm the points brought forward in this memo. in so far as we have had trouble in obtaining satisfactory running of our engines whilst cars were on test. The chief weakness of our carburation is at full throttle low engine speeds, and if the distribution is poor, which we find is the case unless the induction pipe and throttle are carefully and accurately made, full throttle slow running is hopeless. One cylinder is exhausting black smoke simultaneously with another cylinder "popping back" due to weakness. It is surprising how distribution is so easily upset. Induction pipes have to be made clear, smooth, free from "pockets" or projections, and restrictions at the joints. The throttle, however, is the worst feature for affecting distribution. The port in this throttle must be clear, and the dimension, especially its depth on the lower portion of the throttle, is of vital importance. (The annulus on the body.) We can inspect a throttle and anticipate the distribution, and action has been taken for more accurate dimensions to be obtained with these throttles by proper machine production methods. I bring this point to your attention so that the importance of same will receive your attention in experimental and investigation work, and in your specification to the works for production in dealing with new models. Having got good distribution we are on the right track for good efficient power; especially can good economic consumption be obtained. Also, we have more effective petrol control range, and can run without "popping" on attenuated mixtures, and there is less trouble in getting away with the car after starting up under cold conditions. The engine is also more satisfactory when running under cold conditions; there is less sooting up of the plugs and obnoxious fumes from the exhaust, also less tendency for "popping" in the carburetter. The engine will also maintain a better torque at low speeds and will not so readily commence to "choke" after continued running on full throttle at slow engine speeds. | ||