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).
Letter from F.M. Aspin & Co. Ltd. enclosing drawing No. C.144 for engine porting and discussing experimental work.
| Identifier | ExFiles\Box 134\1\ scan0227 | |
| Date | 14th June 1940 | |
| TELEPHONE-BURY 1554 TELEGRAMS-"NIPSA" BURY CABLES-WESTERN UNION "NIPSA" BURY F.{Mr Friese} M.{Mr Moon / Mr Moore} ASPIN & CO. LTD. INTERNAL COMBUSTION ENGINES ELTON BURY ENGLAND Chairman and Managing Director: F.{Mr Friese} M.{Mr Moon / Mr Moore} ASPIN Directors: T.B. ASPIN, W.R. CROW, L. CLOUGH, C. RIDDEL, O.E. VARLEY YOUR REF OUR REF FMA/AG 14th June, 1940. W. A.{Mr Adams} Robotham, Esq., Experimental Dept., Messrs. Rolls-Royce, Ltd., DERBY. Dear Mr. Robotham, Further to your visit last week, I enclose drawing No. C.144 showing what we consider a reasonable porting for an engine of 5 1/2" bore. The opening diagram is a corrected one for radii. Perhaps you would give us some idea of how this compares with what you require. We believe we could do better, but this would entail some experimental work with regard to the running of the rotor, but, as the rotor is shown, we can guarantee its satisfactory working at cylinder pressures of 1,000 lbs per square inch. Your comments are awaited with interest. Kind regards, Yours sincerely, F.M. Aspin ALL COMMUNICATIONS TO BE ADDRESSED TO THE COMPANY [Handwritten notes:] [Top right:] PNR Please include this in your valve opening diagram analysis FILE [Top left, stamped:] 1129 [Middle right, initialled:] Rm{William Robotham - Chief Engineer} [Bottom:] The Merlin is a 5.4" Eng[ine], to correct area 6.5 x 29.4 / 30.2 = 6.3. | ||