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. to W.A. Robotham discussing the manufacture and performance of a Cylinder Head.
| Identifier | ExFiles\Box 134\1\ scan0200 | |
| Date | 5th February 1944 | |
| F.M. ASPIN & CO. LTD. INTERNAL COMBUSTION ENGINES ELTON BURY ENGLAND TELEPHONE - BURY 1554 TELEGRAMS - "NIPSA" BURY CABLES - " " WESTERN UNION - "NIPSA" BURY Chairman and Managing Director. F.{Mr Friese} M.{Mr Moon / Mr Moore} ASPIN Directors - T. B. ASPIN W. R.{Sir Henry Royce} CHOWN L. CLOUGH E.{Mr Elliott - Chief Engineer} RIDDEL G.{Mr Griffiths - Chief Accountant / Mr Gnapp} E.{Mr Elliott - Chief Engineer} VARLEY YOUR REF OUR REF FMA/PC Handwritten notes: TROT Is this what is wanted. JNR{Charles L. Jenner} 5th February, 1944. CONFIDENTIAL. W. A.{Mr Adams} Robotham, Esq., Messrs. Rolls-Royce Ltd., DERBY. Dear Mr. Robotham, I am in receipt of your letter of the 31st January. I would be very pleased to collaborate with you and manufacture a Cylinder Head for the 3½ x 4½ unit. In this size of Cylinder with a compression ratio of approximately 10-1 we would guarantee a fuel consumption of .45 lbs. per brake H.P. hour at maximum torque, but would expect a reading in the region of .4 lbs. per B.H.P. hour under favourable conditions. A B.M.E.P. of about 150 lbs. per square inch would also be expected, depending on the temperature of the induction gas. As a point of interest, I enclose a Power Curve (G.23) of a 4.1 litre 6 Cylinder Engine designed for heavy transport duty with expected and guaranteed performances. In answer to your last paragraph, you will note that a power curve is given showing a B.M.E.P. of 143 lbs. per square inch, being the maximum figure obtained from the Engine in a stripped condition. The 132 B.M.E.P. figure is from the complete assembled power unit including a transport size Generator under full /Contd. | ||