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).
Report correcting the specific weight of the 20 HP reciprocating parts and comparing tubular connecting rod designs with Lorraine and Hispano cars.
| Identifier | WestWitteringFiles\R\2October1927-November-1927\ 24 | |
| Date | 8th October 1927 | |
| To R.{Sir Henry Royce} from Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} 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 Hs{Lord Ernest Hives - Chair}/Rm{William Robotham - Chief Engineer}3/LGI 8.10.27. X4214 X8030 X5030 TUBULAR SECTION CONNECTING RODS. In a previous report comparing the reciprocating specific weight of the 20 HP. and the Lorraine, we gave the former as 1.72 lbs. This should actually have been 1.434 lbs., the error being due to a high compression ratio piston weight being taken. We attach two tables of the comparative weights of the Hispano, Lorraine and RR. cars. Assuming the 20 HP. rod is the same length as that of the Lorraine, we still should be .163 lbs. lighter which would about compensate for larger bearings. The Lorraine tubular rod is ~~about~~ of the lightest construction we have seen of this type, but even so it will be clear from the analysis that little or nothing has been saved in weight by adopting this design. The same conclusion is reached by comparing the Hispano and the 40/50, the tubular rod again being slightly heavier. In both cases it will be noted that the piston assembly of the RR. is heavier than that of the corresponding foreign car. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} | ||