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).
Modifications needed for the 'Heron' model, including front wheel brakes, an air pump, and exhaust system changes.
| Identifier | Morton\M22\ img205 | |
| Date | 18th September 1922 | |
| MODS. NEEDED FOR FWB. HERON AIR PUMP(BRAKE SYSTEM) EXH HEATED THROTTLE To BY.{R.W. Bailey - Chief Engineer} from R.{Sir Henry Royce} c. to CJ. c. to Wor.{Arthur Wormald - General Works Manager} c. to Hs.{Lord Ernest Hives - Chair} c. to Sp.{Mr Spinney} R2/118.9.22. RE 40/50 ("HERON") X.4550. X.3850. In fitting front wheel brakes it has been found necessary to narrow the front of the frame slightly to keep the lock the same, also alter the dumb irons. It has been found a great help to have only one pair of brakes on the rear axle, i.e., we retain the large 17" drums and remove the 12" brakes. The exhaust system needs to be entirely different. We hope to use the cutout silencer as we are trying for Goshawk. The small manifold boxes will be used on the cylinders and the terminal pipe next will be altered and I hope made lighter and cheaper with 2 1/4" pipe. The engine has an air pump on the camshaft, entailing considerable alteration to the slipper wheel, wheelcase, and slight alteration to the crankcase. You already have much instruction including the frame and front axle. We hope this move will include the introduction of exhaust heated throttle, and earthed wiring if single pole lamps can be used on this chassis. R.{Sir Henry Royce} | ||