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).
Excessive weight of new connecting rods and proposing design modifications.
| Identifier | ExFiles\Box 132\2\ scan0219 | |
| Date | 17th June 1941 | |
| Handwritten top: Rm{William Robotham - Chief Engineer}/HH. Can this be made from existing pieces. 1116 Rm{William Robotham - Chief Engineer} To Rm.{William Robotham - Chief Engineer} from Jnr.{Charles L. Jenner} c. to Rm{William Robotham - Chief Engineer}/HH. c. to Rm{William Robotham - Chief Engineer}/TAS.{T. Allan Swinden} Jnr.{Charles L. Jenner}8/SW.26.6.41. Conn Rods & Crankshaft Dampers. Rm.{William Robotham - Chief Engineer}1/RH.{R. Hollingworth}17.6.41. Handwritten right: Rm{William Robotham - Chief Engineer}/ Yes. Existing rods RE.297/8 can be altered to suit. HH/Aspley SUBJECT: The latest Rods are 3 1/4 ozs. too heavy. We all know the reason why the latest rods have excess metal, but what is of more interest, is that the design of a big end with a Vandervell Shell is basically 1 1/2 oz. approx. heavier than with an alum bearing. If we divide the rod into three parts :- SMALL END STEM. BIG END. 2.6. ozs 5.3. ozs 20. ozs. Handwritten middle: Rm{William Robotham - Chief Engineer} we can visualize the disadvantage of the 1 1/2 oz. additional weight. The explanation for the basic heaviness is :- (1) The side control of the rod can not be taken on the bush, therefore the width of the rod is increased by adding .135 of steel. (2) Since the satisfactory aluminium bearing was .125 thick (on the original rod) then for the same weight the Vandervell shell should be .042 thick, but it is thicker namely .072. (3) There can be no drastic reduction to the outside of the big end because the keys of the Vandervell shell make local weakness to the sections. We have produced PL.695 showing a saving of about 1 3/4 ozs. without adding to the cost or reducing the strength of the original sections. Jnr.{Charles L. Jenner} (signature) Original to Rm{William Robotham - Chief Engineer}/HH. Prints to Ashby & Jnr.{Charles L. Jenner} | ||