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).
Proposed modifications to the Wraith 'Stromberg' D.C.42 Carburetter for the 25/30 HP
| Identifier | ExFiles\Box 7\4\ X 608 Carburetter-page09 | |
| Date | 15th July 1937 | |
| P 608. on 1033. Mx.{John H Maddocks - Chief Proving Officer} from Rm.{William Robotham - Chief Engineer} Rm{William Robotham - Chief Engineer}14/R.15.7.37. WRAITH 'STROMBERG' D.C.42 CARBURETTER. We are proposing to modify the specification of the standard 'Stromberg' D.C.42 Carburetter for the 25/30 H.P. in the following manner:- (1) Main feed hole, floatchamber to main jet increased from .106" to .156" dia. Free flow to main jet at present is only 26 pts/hr. " " " " " with .156" dia. is 60 " (2) Idle jet tube at present is 64 and this does not give a very sensitive setting. A smaller jet of 68 or 70"is suggested as an improvement. (3) Choke valve torsion spring E.61387 to replace present standard. This spring is stronger and overcomes the gumming up and sticking of the choke valve in service. We are sending one of these carburetters over to you to enable you to give it a confirmatory test. Rm.{William Robotham - Chief Engineer} | ||