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).
Suggestions for Goshawk 11 engine carburation improvements and test feedback.
| Identifier | ExFiles\Box 31\4\ Scan030 | |
| Date | 2nd April 1922 | |
| X1487 EP.{G. Eric Platford - Chief Quality Engineer} from R.{Sir Henry Royce} ) c. to Hy.{Tom Haldenby - Plant Engineer} ) c. to FH. ) from R.{Sir Henry Royce} c. to LHS.{Lord Herbert Scott} ) c. to CJ. and BJ. c. to Wor.{Arthur Wormald - General Works Manager} c. to Hs.{Lord Ernest Hives - Chair} c. to E.{Mr Elliott - Chief Engineer} and Da.{Bernard Day - Chassis Design} c. to BY.{R.W. Bailey - Chief Engineer} c. to EFC R/LG2.4.22. GOSHAWK 11. SUGGESTIONS X4219 X1487 Carburation. I was not aware that there was any difficulty about this. It now seems that it is thought that the mixture is in some way wrong at slow speeds and was better in this respect with the S.U. Carburetter. Our experiments here show that with .675 high speed and .4 low speed venturi the engine pulled well down to 400 revs. and permits of sudden or slow opening of throttle. It was more silent and I think more powerful than with the S.U. which we fitted and went up the same hill equally slowly. The conclusions arrived at are, that the high speed throat was at .65 or less too small for the extra air valve. It is possible that it will be found to be still better with .7 high speed throat which I believe was the size estimated for at W.W. There were some dimensions also not correct - the sample standard carburetter should be checked for dimensions by H.{Arthur M. Hanbury - Head Complaints} Certain simplifications might be found and some parts made less susceptible to variations in manufacture. Aluminium seems wrong for high speed venturi. The test plate should prove the correct mixture at all speeds by working the jet control, with the air valve as now made which appears correct - the throat sizes can be increased until mixture is slightly too weak at 300 or 400 R.P.M. full throttle when it can be considered that the test size has been passed. There should be a distinct gain in petrol consumption due to the alteration here suggested of a .675 or .700 throat with other parts as at present. 4-Goshawk-11. (Hs.{Lord Ernest Hives - Chair} car at Le Camdel) This car picks up and climbs better than any car I have ever tried - R.R. and others. It might suggest that the gear is too low, certainly it is low enough also that open car might have freer exhausts - not noisy, but slightly freer than covered cars, say by fitting freer or less number of diaphragms. For simplicity we want to avoid a cut-out. contd:- | ||