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).
Technical memo recommending against changing the connecting rods and discussing crankshaft lubrication for the 'SS' engine.
| Identifier | WestWitteringFiles\T\November1928\ Scan017 | |
| Date | 9th November 1928 | |
| To R.{Sir Henry Royce} from Hs.{Lord Ernest Hives - Chair} c. to BJ. Wor.{Arthur Wormald - General Works Manager} c. to E.{Mr Elliott - Chief Engineer} DA.{Bernard Day - Chassis Design} c. to BY.{R.W. Bailey - Chief Engineer} ORIGINAL Hsl/LG9.11.28 'SS{S. Smith}' ENGINE. X7720 X7030 X 7010 CONNECTING RODS. We recommend that on the first batch of 'SS{S. Smith}' cars we stick to the present Phantom conn. rod and not change to the tubular type. The present Phantom rod is interchangeable with the tubular rod. We have proved that it is risky to leave the oil pipe off the gudgeon pin, the engine will run satisfactorily but we get knocks from the little end if the clearance increases a very small amount. By adding the oil pipe these knocks are overcome. We have found no advantage in the running of the engine with the tubular rods and therefore stongly recommend that we stick to the present standard rod for which we have all the tools and all the experience. CRANKSHAFT LUBRICATION. On the above engine we have been running with the pipes in the crankshaft and no grooves in the bearings similar to the latest aero engines. The chief effect of this is that it reduces the amount of oil leaking from the crankshaft. On the car we have been running (12-EX) with this scheme we found that we had to run with a much higher oil pressure in order to ensure that all parts were well lubricated. We have come to the conclusion that we cannot afford to reduce the amount of oil leaking from the bearings compared with the present std. Phantom. contd :- | ||