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 carburetter design issues and outlining future development plans.
| Identifier | ExFiles\Box 121\3\ scan0072 | |
| Date | 21th June 1940 guessed | |
| THE S.U. CARBURETTER CO. LTD. ADDERLEY PARK, BIRMINGHAM. 8. 2. the large Carburetters it has fallen far short of this, and I do not feel that the results obtained with this low ratio are good enough to submit to you. Although the large Carburetter is perfectly serviceable it means that we have got to run with a manifold depression of about 18" of water head in order to produce sufficient suction to raise the fuel under severe conditions. It is quite clear that, had we merely scaled up the small Carburetter, in order to arrive at the dimensions for the larger one, we should have produced at least as good a result as in the case of the small one. Actuated, however, by the desire to reduce the overall height of the larger Carburetter we departed from the venturi proportions used in the small type, and this, I am afraid, has given rise to our poor results. We know that we can produce at least as good a multiplication, but we have to increase the length-diameter ratio of the venturi, and this is now being done, new patterns being now in hand. Please accept our regrets for this set-back, and rest assured that we shall proceed with all speed to produce some further Carburetters which we shall feel more inclined to submit to you. Yours sincerely, TH Mann | ||