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).
On the road testing and modification of 20 HP carburation, comparing a modified Goshawk-11 engine to an original Goshawk-1.
| Identifier | WestWitteringFiles\J\May1923\ Scan44 | |
| Date | 10th August 1923 | |
| To R.{Sir Henry Royce} from Hs.{Lord Ernest Hives - Chair} c.c. to CJ. c.c. to E.{Mr Elliott - Chief Engineer} c.c. to Dm.{D. Munro} c.c. to HY.{Tom Haldenby - Plant Engineer} ORIGINAL Hell/LG10.8.23. 20 HP. CARBURATION. X4228 From tests on the road we have proved that the original Goshawk-1 with the latest scheme of induction pipe and exhaust heated throttle gave a better performance as regards power, consumption and carburation, compared with the present standard 20 HP. chassis. We have therefore fitted up a 20 HP. Goshawk with a similar scheme to that on Goshawk-1. We have fitted an exhaust heated throttle - the heated jacket is not as big as that on Goshawk-1 because we have not sufficient room to get this in on Goshawk-11 engine as the carburetter would foul the steering. We have also had to slightly increase the compression of the standard Goshawk-11 in order to make it identical to Goshawk-1. We have had to leave .1" on the top of the pistons. We have also done away with the hot-spot in the standard position as we have had on G-11 and rely solely on the heated throttle. After we had completed these modifications we found that the performance on the road with the same gear ratios, same weight and all other conditions, the cars gave practically identical performances. We are not in a position yet to be able to give a definite value to the different modifications. It is necessary for us to try them on two or three engines before we can do this to get an average improvement. contd:. | ||