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).
Design of bonnets and the effectiveness of radiator shutters for the 40/50 chassis.
| Identifier | ExFiles\Box 38\2\ Scan044 | |
| Date | 5th June 1919 | |
| C.O.P.Y. To R.{Sir Henry Royce} from EH. c. to W. c. to Hn.{F. C. Honeyman - Retail orders} c. to E.{Mr Elliott - Chief Engineer} c. to De. X.3456 ✓ X.3499 X.3421.- RE BONNETS FOR 40/50 CHASSIS. The improvement in the cooling of the water with the four shutters open and four shutters closed is 4 to 5%. The difference in floorboard.temperature is about 3%. Shutters have been found necessary on very long hills in Austria, Italy and India. Now we are fitting the round tube radiator, the radiator itself is more efficient as regards cooling 4 to 5% Considering that only a very very small percentage of our cars ever use the shutters at all, we consider they are rather elaborate. they are expensive pieces to make because each shutter is pannelled out by an end-mill in order that the paint shall not be scratched when sliding them along. The percentage of improvement is so small when all four shutters are open that if ever shutters are found necessary the whole of them will be used at one time. there does not appear any need of having shutters which allow for adjustment; they can be in the form of plates which are held on with 4 bolts. As regards whether shutters should be retained on the new chassis, this depends a lot on how much room is allowed for the air to pass the dash board. we have had a number of complaints of the difficulty of opening the bonnets on our cars. we have tried Contd- | ||