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).
Bensport radiator scheme, piston failures, and testing plans for the Bensport car.
| Identifier | ExFiles\Box 87\1\ scan0024 | |
| Date | 28th March 1933 | |
| COPY. 8240 To Sg.{Arthur F. Sidgreaves - MD} From Hs.{Lord Ernest Hives - Chair} c. to Wor.{Arthur Wormald - General Works Manager} c. to E.{Mr Elliott - Chief Engineer} c. to By.{R.W. Bailey - Chief Engineer} Hs.{Lord Ernest Hives - Chair}4/MJ.28.3.33. BENSPORT RADIATOR. Replying to Sg.{Arthur F. Sidgreaves - MD}18/E.27.3.33. We have received a scheme from W.W. of a Bensport radiator built up without shutters but with stone guard. We still however require a scheme from E.{Mr Elliott - Chief Engineer} with the thermostat arranged to short circuit the radiator. We think it would be unwise to delay building up our next Bensport car in order to incorporate this scheme, but it is quite possible that it will be ready before we wish to send the car to France. As regards the breaking of the pistons on the Bensport we think these are satisfactorily explained by the fact that these pistons were cast in the wrong alloy. They were rushed through to get the car running in France and the alloy used was one not suitable for pistons. It will be remembered that the first pistons which failed on the Bensport in France was due to the gudgeon pin locking arrangement. Those were made in the correct material. It was the set which was sent out to replace those which have given us trouble with breaking. Dismissing the question of faulty material, the difference in the pistons which were originally fitted to Bensport and the present standard 25 HP. which it has been agreed we should use, is that the standard 25 HP. piston is .030" less in height from the gudgeon pin. This effects the compression ratio but the head has been modified to allow for this so that the standard piston can be used. The car in France is now running again with the pistons which we expect to use on the Bensport production. We have asked them to run the car at high speeds and to do a certain amount of work on the Monthlery Track so that high speeds can be maintained with safety. There are a number of features on the Bensport car running in France which it is not intended to use on any future cars, but on the other hand there are a very large number of features which we require running to gain experience and for that reason we want to get all the mileage we can out of the car in France. Hs.{Lord Ernest Hives - Chair} | ||