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).
Continued report discussing engine crankcases, bearings, chassis frames, and works equipment.
| Identifier | WestWitteringFiles\D\May1920\ Scan43 | |
| Date | 1st May 1920 | |
| TO HS.{Lord Ernest Hives - Chair}DA.{Bernard Day - Chassis Design} & HY.{Tom Haldenby - Plant Engineer} -5- EL/G18/5/20 Contd. caps in the bottom half of the crankcase are very pronounced. They apply to some extent only to the "Buzzard" engine, and in view of this Mr. Royce has decided that the "Buzzard" shall be a com- promise between the two systems so that it shall have the conven- ience of the present car engine in respect to main bearings without the objections to the form of the crankcase. The bearing caps will be used in conjunction with cross webs in the bottom half. Mr. Hives submitted further information with respect to the disadvantages of the type of big end used on the "Condor" as compared with that used on the "Eagle" engine, chiefly in respect to ease of manufacture and repair. Mr. Royce agrees to try both types for the "Buzzard" since this is now possible, owing to the decision regarding the lower half of the crankcase, and says the Buzzard rod of the artic- ulated type will have 20° less angle, and will probably be designed with the fork on the articulated rod instead of on the main rod. X.3813. Referring further to crankshaft and big end bearings, Mr. Royce stated that it was his opinion that we always fitted up our stuff too tightly. Mr. Bailey thought that with the new reamed bearings our engines are much more free. It was further stated that our main bearings will run up to .005" clearance beyond which they will knock. It is difficult to maintain the oil pres- sure with big slacks in the bearings, and this is the first limit that is found. If a car is knocking in the main bearings and the oil be changed for thicker oil or for castrol, then the knock- ing will cease. Mr. Royce says that if we are limited in this direction by the maintenance of the oil pressure, then we must use greater oil pump capacity. X.4043. With regard to the Buzzard chassis frame, six sets of which we shall shortly be putting on order, a point to be decided was the gauge of the material to be used in the pressing. Mr. Royce remarked that we have a lighter engine and that we must save weight. It was stated by Messrs. Day and Hives that the weakest point of the present 40/50 frame as shewn on the pump test is the front horns. Mr. Royce considered that we should test the "Buzzard" frame in material .128" thick, that is, 10 S.W.G., and that the Buzzard front horns would not have so much load to carry, in view of the lighter weight of the engine. X.4122. With regard to the spare wheel behind the petrol tank on the new chassis, this may foul touring body and cabriolet hoods. Mr. Day will look into and supply a figure for the permissible height for this wheel. WORKS' EQUIPMENT. X.3054. Mr. Royce thought that we should do more press work at Derby, but says do not sell the small power presses that we are using now to get larger ones, as he was afraid that this might re- sult in doing small work on big presses. He thought that we should be able to keep a press busy that would be big enough to do the silencer snout job. For presswork to be ordered outside, Mr. Royce recommended that we should try Sankeys or Rubery Owen. | ||