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).
Test run report for a Stromberg Carburetter, noting issues with rich mixture, performance, and fuel consumption.
| Identifier | ExFiles\Box 101\4\ scan0158 | |
| Date | 7th January 1936 | |
| Wor.{Arthur Wormald - General Works Manager} From Ha/GWH.{George W. Hancock - Head Chateauroux} c. to E.{Mr Elliott - Chief Engineer} c. to By.{R.W. Bailey - Chief Engineer} Ha/GWH.{George W. Hancock - Head Chateauroux}7/MA.7.1.36. 21.G.IV. UNIT NO.C.15. Specification to RHC.{R. H. Coverley - Production Engineer} 31.10.35., 19.10.35., 14.12.35 & 2.1.36. Test run for 842 miles with Stromberg Carburetter. Starting from cold. The carburetter was too strong immediately the engine fired, excessive black smoke being emitted from the exhaust. The engine quickly choked if the choke lever was left in position. The pistons squawked and would be quickly ruined under these conditions. With the choke released immediately the mixture was strong enough to get away under normal traffic conditions, only when the accelerator pedal was sharply depressed was there any hesitation. The spring of the choke valve could, with advantage be weaker to allow the choke valve to open up to its stop. The carburetter was too strong throughout the range. On hills of 1 in 5 with the speed of the car reduced to 15 M.P.H. top gear, the induction pipe loaded up, black smoke was emitted and misfiring commenced. Changing into third or second gear made no improvement. On slight gradients the engine pulled very steadily down to 5 M.P.H. Slow running was not too steady on the level, and when idling was regular. It was not as good as with the previous engine. Petrol consumption was on the heavy side - 12.02 M.P.G. for the 842 miles. | ||