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 the results and further testing of experimental big end bearings.
Identifier | ExFiles\Box 116\1\ scan0035 | |
Date | 25th April 1938 | |
ALL COMMUNICATIONS TO BE ADDRESSED TO THE FIRM AND NOT INDIVIDUALS TELEGRAMS: DENNIS GUILDFORD TELEPHONE: GUILDFORD 1575 (7 LINES) OUR REF JM{Mr Morley}/CS. YOUR REF RM{William Robotham - Chief Engineer}/Mths.{Reg Matthews}3/MH.{M. Huckerby} BY APPOINTMENT HEAD OFFICE AND WORKS DENNIS BROS LTD COMMERCIAL VEHICLE AND FIRE ENGINE MANUFACTURERS GUILDFORD SURREY ENGLAND DENNIS ESTABLISHED 1895 A B C CODE 5TH EDITION LIEBERS 5 LETTER BENTLEYS MARCONI 1020a. 25th April, 1938. Handwritten: MTHS{Reg Matthews} See me Rm{William Robotham - Chief Engineer} Messrs. Rolls Royce Ltd., DERBY. Dear Sirs, We beg to thank you for your letter of the 22nd inst., dealing with the results which we have already obtained from the experimental big end bearings. We will arrange to let you have further information as you suggest, and directly the engine has run approximately 200 hours we will have another series of photographs taken and send them on to you for your inspection. We will endeavour to give you a little warning before the engine is stripped for this work so that if you care you can arrange to make an inspection. With regard to the comparison between these bearings and our standard lead bronze type, it is somewhat difficult for us to say anything with regard to oil consumption, for the bearings are being used on an engine which is running on piston and piston-ring tests. Under these conditions, while the supply of oil to the cylinder wall is fairly uniform, yet our variations in ring equipment prevent us from making any definite comparison with previous runs. As far as the general condition of the bearings themselves is concerned, this is shown to be much better than we normally observe from our standard bearings. We have suffered considerably due to segregation of the constituents of the copper lead bearings, and in anything like a 100 hours run we have usually been able to find that the heavily loaded surface immediately under the centre of the connecting rod is showing signs of distress. Improvements have recently been made on the bearings in question, and we have also been able to obtain bearings from an alternative supplier, with a result that conditions today are much better. In spite of this, however, we are considering the test of your bearings in connection with a new engine on which we are working at the present time. We should be glad, therefore, if you would advise us of the name or the specification under which this material will be CUSTOMERS' VEHICLES DRIVEN AT OWNER'S RISK ONLY. | ||