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).
Extract detailing issues with the P.2. model's rear wheel arch, subframe centre bearing, and subframe manufacturing.
| Identifier | ExFiles\Box 14\8\ Scan262 | |
| Date | 15th July 1930 | |
| X. 7380. EXTRACT FROM :- BY.{R.W. Bailey - Chief Engineer} HS.{Lord Ernest Hives - Chair} c. to C. Wor.{Arthur Wormald - General Works Manager} c. to EP.{G. Eric Platford - Chief Quality Engineer} JLE.{J. Lee Evans - Chassis Test Manager} DA{Bernard Day - Chassis Design}/EV.{Ivan Evernden - coachwork}1/M15.7.30. X.7770. X.5770. (1) P.2. REAR WHEEL ARCH. The width between the brake drum arches on P.2. is less than for P.1. though the track is the same. This is due to the change in the springing causing more tucking in of the wheel on single wheel bump. When we ask the coachbuilders to mount their bodies at the rear centrally with respect to the brake drums instead of centrally with respect to the chassis frame it so often happens that the scuttle isolation gap is .2" wider on one side than the other. For this reason they are not able to proceed far with the body before the receipt of the chassis and one of the chief virtues of the subframe is lost. We understand the rear axle may be .250" out of centre with the chassis frame either way. This would mean a variation in the scuttle isolation gap of about .125 total, which is too much. We wish you to see what can be done with a view to holding the dimensions of the rear axle relative to the chassis frame within .125" either way. We cannot agree to reduce the width between the wheel arches to account for this present possible .500" of variation as that would make the maximum rear cushion permissible only 47". When we go to the 60" rear track we might be prepared to permit greater limits to the variation of the position of the rear axle. (3) P.2. SUBFRAME CENTRE BEARING. We repeatedly find on mounting abody that the subframe rests on the fore and aft bearings without packing, and is quite clear of the centre bearing. Coachbuilders take out the bolt and weld metal on to the head. In some cases to avoid this the packing is removed from the rear bearing, and then although contact is obtained on the centre bearing the rear cross rail of the body fouls the petrol tank. We understand that subframes and chassis are erected so that there is contact on the centre bearing without the metal packing under the rear bearing. We would prefer the centre bearing to always be high rather than low, and this because it is always possible to increase the packing under the rear bearing. We therefore wish you to lift the centre bearing so that we shall always need packing under the rear bearing. (5) P.2. MANUFACTURE OF SUBFRAME. Coachbuilders are frequently pointing out to us that the subframes they receive are not rectangular, but are parallelograms to the extent of a variation of .500 in the two diagonals. We suggest that all subframes should be tested on a jig before delivery and that a jig of the subframe should be dropped on to every chassis | ||