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).
Issues with piston ring leakage and fumes, alongside tests on induction and exhaust pipe modifications.
| Identifier | ExFiles\Box 50\3\ Scan057 | |
| Date | 20th April 1921 | |
| Contd. -2- 20.4.21. some Double Seal Piston Rings. They were being sold by the Double Seal Co., 1834 Broadway, N.Y. City. Will you please arrange to send over about 4 dozen of these rings. We are not satisfied with our present piston rings. We are getting a fair amount of leakage and we are getting a number of complaints of fumes in the bodies of closed cars. We have been carrying out further tests with the 1" pipe through the centre of the induction pipe as shown in your drawing XA.423. We have copied in absolute detail the arrangement shown on that drawing. We have made a test by taking out the 1" pipe from the induction pipe and blanking up the holes which are left and running the 1" pipe outside connected up to the exhaust in the proper manner. By this means we can measure what temperature the pipe gets to and how quickly it becomes hot. We find that it takes relatively a very long time to get hot and that the pipe never reaches a temperature much above the water temperature. We believe, and our tests confirm this, that most of the improvement you had with fitting this pipe was due to the increase velocity in the branch pipe. It requires very little alteration to increase tremendously the heat of this 1" pipe. The first essential thing is to try and arrange the exhaust pipe fittings so that they are only in the blast of the exhaust from nos. 1 and 6 cylinders. The next thing is to increase, if possible, the diameter of the pipes. Although we agree that extending the exhaust pipe inside the 1" pipe enables the centre of the pipe to be heated up first and also maintains this at a much higher temperature than the ends, we find that because this means restricting the size of the exhaust pipe the better results are obtained if it is dispensed with and the maximum size of the exhaust pipe is used. HS. {Lord Ernest Hives - Chair} | ||