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 Alta Car & Engineering Co. Ltd. regarding their 2-Litre supercharged racing engine and AC 9 bearing material.
| Identifier | ExFiles\Box 116\3\ scan0021 | |
| Date | 22th April 1939 | |
| TELEPHONE—ELMBRIDGE 3157. C.T.S. 1020a TELEGRAMS—ELMBRIDGE 3157. ALTA CAR & ENGINEERING Co. LTD. Directors — G.{Mr Griffiths - Chief Accountant / Mr Gnapp} TAYLOR. L. TAYLOR. April 22nd, 1939. FULLER'S WAY, KINGSTON BYE-PASS, SURBITON. Your Ref. Experimental. Rm{William Robotham - Chief Engineer}/CTS{C. Trot Salt - Carburation}/1/MH.{M. Huckerby} Our Ref. GT.LV. Messrs. Rolls Royce, Ltd., Derby. Dear Sirs, With reference to our previous correspondence in September of last year with regard to your AC 9 bearing material, we enclose herewith a sketch showing the arrangement of the connecting rod and crankshaft, also a print of the connecting rod. The engine we now wish to try a set in the big ends is one of our two litre racing engines and we had thought of getting them fitted for a race in the near future. We should like to use our standard rod with a bored out big end if it will allow of this operation to a sufficient extent. The engine is a 2 Litre supercharged four cylinder unit with a three bearing partially counterbalanced crankshaft. The boost pressure is 18 - 20 lbs. guage, the compression ratio 7.8 to 1, and the usual fuel 97% Methonal. These engines give 250 B.H.P. at 5800 r.p.m. and the power curve is fairly flat until it reaches 6500 r.p.m., the bore and stroke are 79 m.m. x 100 m.m. The oil is Castrol R with Collodial graphite added; the pressure, neglecting centrifugal effect 120 lbs. per sq. in. Tecalemit felt type filter is used, and in addition the crank shaft acts as a centrifugal filter, the shaft is made of Nitralloy. We should be very glad if you could give us some information on the following points:- | ||