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).
Carburetter level settings, adjustments, and production quality issues.
| Identifier | ExFiles\Box 92\2\ scan0161 | |
| Date | 30th June 1933 | |
| -2- set to 1.375±.025 below the parting surface of the float chamber cover. The level can be accurately set by measurement of the level in the high speed jet adjustment well. (d) After the level has been adjusted the needle movement should be checked and should not be less than .115; excess of this movement is immaterial. Failure to obtain this minimum movement may be either; measurement from the internal base of the float chamber to centre line of float pivots is less than the drawing limits (1.775), or the float assembly is overweight. Considerable variation amounting to .325" has been found in the levels of two production carburetters. In the first case, 104-MY, SG{Arthur F. Sidgreaves - MD}'s car, the level was checked and found to be .900" below the parting surface which is .150" higher than the standard setting. This car flooded on a gradient no steeper than 1 in 15. Secondly a carburetter was borrowed from production which only flooded on gradients steeper than 1 in 8, and upon checking, the level was found to be 1.225" below the parting surface or .175" lower than the standard setting. We must insist that the internal finish of the carburetter and its parts be good with all rough surfaces and burrs removed, as otherwise it is impossible to obtain consistent results from the carburetter. The condition of the carburetter on 104-MY was such that it was necessary to return same to the works in order to improve its finish throughout. Hs{Lord Ernest Hives - Chair}/L.H.Swindall Hs{Lord Ernest Hives - Chair}/G.H.Whyman. | ||