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 Dennis Bros Ltd discussing crankshaft bending loads and bearing tests for a 'C' Type 4-cylinder engine.
| Identifier | ExFiles\Box 116\1\ scan0063 | |
| Date | 8th September 1938 | |
| ALL COMMUNICATIONS TO BE ADDRESSED TO THE FIRM AND NOT TO INDIVIDUALS BY APPOINTMENT HEAD OFFICE AND WORKS DENNIS BROS LTD COMMERCIAL VEHICLE AND FIRE ENGINE MANUFACTURERS GUILDFORD SURREY ENGLAND TELEGRAMS: DENNIS GUILDFORD TELEPHONE: GUILDFORD 1575 (7 LINES) OUR REF. JM{Mr Morley}/EMA. YOUR REF. RM{William Robotham - Chief Engineer}/CTS.{C. Trot Salt - Carburation}I/JH. DENNIS ESTABLISHED 1895 A B C CODE 5TH EDITION LIEBERS 5 LETTER BENTLEYS MARCONI 8th September 1938. Messrs. Rolls Royce Ltd., D E R B Y. Dear Sirs, We duly received your letter of the 3rd inst. for which we thank you. We quite agree with your remarks regarding the presence of bending loads on the crankshaft used in our 100 x 120 "C" Type 4-cylinder engine. As far as this is concerned we would inform you that we have now decided to use counter-balance weights on the modified type of crankshaft, and this we anticipate will overcome the majority of the trouble which we have experienced with the centre main bearing. As matters stand we think that it is hardly worth while carrying out a further test with either your A.C.6 or A.C.9 material until we have supplies of the counter-balance shafts and as soon as we are in this position we will make comparative tests with your A.C.9 material, for we have a small supply of these bearings on hand at the present time. We will advise you of the result which we obtain. Regarding results which we have obtained with lead bronze shell lined with lead base white metal, we have pleasure in advising you that these bearings are perfectly satisfactory at 3000 r.p.m. with oil temperature 90/95° C, but on a further test run at 3250 r.p.m. with oil at 100/105° C, trouble has been experienced, and it would appear that it would not be safe for us to run beyond the conditions imposed by the first of these tests. [Handwritten notes:] [Top Center:] 1020a [Bottom Right:] CJS File 1020a (Dennis section) [Left Margin Text:] CUSTOMERS' VEHICLES DRIVEN AT OWNER'S RISK ONLY. | ||