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).
Diagram showing bonnet movement measurements in thousandths of an inch under chassis twist conditions for various engine mounting configurations.
| Identifier | ExFiles\Box 14\5\ Scan219 | |
| Date | 18th June 1931 guessed | |
| BONNET MOVEMENT IN .001 INS NEW SIDE FRONT & OFF SIDE REAR ROAD WHEELS RAISED 3" FROM THE GROUND FIG. I P II 4 ENGINE FEET SOLID RAD. DASH BONNET RADIATOR O.S. | N.S -2 | +8 -15 | +12 +2 | 0 +10 | -12 FIG. II P II DIAMOND MOUNTING SOLID RAD. -38 | +56 -46 | +76 +39 | -24 +42 | -75 FIG. III P I SOLID REAR ENGINE FEET SHEET ALUM DASH ISOLATED SCUTTLE -65 | +47 -73 | +13 +43 | -29 +76 | -12 FIG. IV P II DIAMOND MOUNTING CENTRAL MOUNTED RAD. 2 STAY TUBES. +1 | -2 +1 | -1 0 | -4 0 | -4 | ||