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).
Experiments and performance issues with S.U. carburetters on Goshawk-11 cars.
| Identifier | ExFiles\Box 31\4\ Scan026 | |
| Date | 27th March 1922 | |
| [Handwritten top middle] X1487 Hs.{Lord Ernest Hives - Chair} CO. R.{Sir Henry Royce} Le CanadelHenry Royce's French residence. from EP.{G. Eric Platford - Chief Quality Engineer} [Top right] EPI/LG27.3.22. RE. GOSHAWK. [Handwritten] X1487 / X4219 We have received your wire as follows:- "ROYCAR DERBY. ROYCE AGREES SHOULD EXPERIMENT WITH S.U. NOT CONVINCED WILL BE PERFECT PERSEVERE WITH OWN. HIVES". As regards 5-Goshawk-11 and 6-Goshawk-11, the carburation with both these cars fitted with standard R-R Carb. was fairly satisfactory, and evidently compares in performance with that you report is actually the case with 4-Goshawk-11. At the same time, there certainly is that trouble of the power falling off below 20 M.P.H. and there being a tendency for loading-up to take place when running on full throttle low speeds and also a tendency for weakness when suddenly accelerating. The S.U. Carburetter man (Mr. Kebble) is still working on his carburetters but we do not appear to be able to reproduce the results we obtained with the first carburetter which you have now in your possession. Although he has been able to obtain similar comparative results on the test bed, we have not been able to obtain similar comparative results with cars on the road, even with 1-Goshawk-11, on which the previous experiment was made and which Mr. Northey states 45% improvement in horse power and performance was obtained. Although this matter is receiving continued attention, we have not been able to obtain anything-like similar results with the S.U. Carburetter on any of the Goshawk experimental cars. This report rather confirms that the S.U. is not perfect and we should not be too ready to rush into adopting it; at the same time we are continuing experimental work on this carburetter and their representative is still having a free-hand to try out alterations, adjustments etc. We take it that you have discussed with R.{Sir Henry Royce} the alterations, adjustments and tests we have made with the R-R Carburetter and we should welcome any further information you could convey to us in regard to any further alterations and adjustments which you think could be tried to advantage. We are rather in an awkward position here at present as CJ. and Sales Dept. generally appear to be rather obsessed with the advantage obtained by the use of the S.U. Carburetter which we feel rather dubious about. 3-Goshawk-11 has returned from the Sales Dept. after their recent trial on this car (the other week-end after you left the works) and they report the car has been very disappointing for performance. CJ. expresses his regret that we should have sent this car with any other than the S.U. carburetter fitted. contd:- [Upside down at bottom] R.R. 189 (500) (H) 296. (15.8.17) M.P. 178549. | ||