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 discussing chassis and coachwork issues regarding rear wheel arch dimensions and scuttle isolation.
| Identifier | WestWitteringFiles\U\2January1930-September1930\ Scan215 | |
| Date | 15th July 1930 | |
| [Crossed out: BY.{R.W. Bailey - Chief Engineer}] ) FROM DA{Bernard Day - Chassis Design}/EV.{Ivan Evernden - coachwork} HS.{Lord Ernest Hives - Chair} ) [Handwritten: HJL ORIGINAL] [Handwritten, crossed out: x7770] [Handwritten, crossed out: x5770] [Crossed out: Copy to C. (for Sales.)] [Underlined: Copy to WOR.{Arthur Wormald - General Works Manager} EP.{G. Eric Platford - Chief Quality Engineer} JLE.{J. Lee Evans - Chassis Test Manager}] I met EP.{G. Eric Platford - Chief Quality Engineer} and JLE.{J. Lee Evans - Chassis Test Manager} at Hooper's last week to discuss chassis and coachwork matters arising out of the test of completed cars. [Handwritten in margin: n380-] (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. [Handwritten in margin: n6b5-] (2) P. 2. SCUTTLE ISOLATION. We shall immediately be making a drawing and issuing instructions for the use of rubber buffers being inserted between the scuttle vertical rail and the pot on the dashboard. A modified scuttle isolation print will be issued to all coachbuilders. As soon as possible we shall make a RR. scheme of this shewing the rubber in a cup in the side of the dashboard pot mounted in such a way that it may be screwed out after the body is mounted. We shall shortly also shew on the scuttle isolation print the instruction that the rubber supplied by us must be compressed the required amount, and should the scuttle isolation gap be irregular those rubbers in the wider part of the gap must have packing washers underneath them until all the rubbers have the same compression. A further item which affects the regularity of the scuttle isolation gap is the thickness of the edge of the dashboard. When we designed the cast dash it was assumed that this edge would be kept constant by surfacing both the back and the front face. If there is no great difficulty we would like this to be done. (1) | ||