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).
Cost analysis comparing components of the Peregrine Chassis against the 20/25 HP model.
| Identifier | ExFiles\Box 1\8\ B001_X100 Engine Chassis-page128 | |
| Date | 12th December 1932 | |
| Hs.{Lord Ernest Hives - Chair} COPY. 84027. Wor.{Arthur Wormald - General Works Manager} from Sft.{Mr Swift} Sft{Mr Swift}2/BH.12.12.32. PEREGRINE COSTS. There are several sections on Peregrine Chassis which do not permit of a reduction equivalent to that required. 1. CRANKCASE AND BEARINGS. - In the first place there are 8 Bearings on the Peregrine against 7 on the 20/25 HP. Double Ops. are required. This is to enable heat-treatment to be carried out between roughing and finishing as required by D.O. To produce bores, even with six-spindle machines and Liners, and to correspond to the similar conditions on the 20/25 HP. is an increase of say 12/13 hours. The Liners are extremely hard, and the bores for receiving the Liners have two fine limit dimensions of .0005". The undercut in the bore is also included. The Tappet faces for carrying the Tappet Brackets are additional. To machine this requires a small cutter, and six equivalent set-ups for depth before these are machined. It is a fairly slow job and must of course be very accurate. The Tappet Cover facing takes longer to machine than the equivalent on the 20/25 HP. 2. CRANKSHAFTS. - On this also we have to look after 8 Bearings against 7. The D/O.{Mr Oldham} insist on the chamfer on the edges of the web. This is additional to the 20/25 HP. and is approximately 4 to 5 hours bonus time operation. The Shaft also is of Nitralloy. We are studying some new machines, and are interested in several new propositions and improvements, in fact we hope to bring this cost down, but at the moment, and following laid-out procedure and present machining methods, it is definitely dearer. 3. FAN. - The design is practically the same, and as our methods of producing the 20/25 HP. are exceptionally good, we can only get a very slight reduction on this Section. Probably the design might consider some scheme which would enable us to produce a cheaper fan. 4. RADIATOR SHUTTERS. - In the main, those parts that have to be machined, fitted, and sweated, and built up, are similar to those on the 20/25 HP. with the exception of the Blade Sections themselves, and it is only on the assembly, rivetting, and sweating of the two halves of the Blade, as on the 20/25 HP. that we can make a reduction. 5. FLYWHEEL AND CLUTCH. - The additional Damping Device is extra. A lot of intricate milling is required, and further, the withdrawal mechanism is more extravagant than the 20/25 HP. We think the Design should give assistance in the cost of the Flywheel and Clutch. We have been able to make a small reduction on this Section. | ||