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 to Vauxhall Motors discussing ignition advance curves and a carburettor issue.
| Identifier | ExFiles\Box 127\4\ scan0107 | |
| Date | 17th March 1938 | |
| 1097. Rml/R.{Sir Henry Royce} 17th March 1938. A.{Mr Adams} Taub, Esq., Vauxhall Motors Ltd., L U T O N. Beds: Dear Taub, We very much enjoyed your visit the beginning of the week. I am sending you some typical ignition advance curves from our standard production engines. Of course, the ignition advance necessarily decreases with the increase in compression ratio, and also with cylinder dimensions. We should like to know, however, whether you consider we might be able to get a smooth combustion characteristic from an ignition advance similar to that depicted in curve 3. We should also be interested to know the ignition advance characteristic of the Chevrolet from which you get the smoothest combustion chamber characteristic. I have been looking over some other ignition advance curves which we have obtained, and I find that as soon as the advance required from 500 r.p.m. to 4,000 r.p.m. gets above 25° on the flywheel and the total advance required covers 40° before T.D.C., that the power starts to fall off and the tendency for the head to detonate increases. I should be interested to see the latest General Motor figures which indicate that the overhead valve engine this year is ahead of the side valve. We have had a certain amount of trouble with the Stromberg carburetter, due to the choke valve jamming closed when a back fire occurs under starting conditions. Have you had this trouble, and, if so, what have you done to eliminate it ? Yours sincerely, | ||