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).
American engine development, supercharger failures, and a visit to Langley Field to discuss compression ignition units.
| Identifier | ExFiles\Box 179b\3\ img140 | |
| Date | 6th January 1931 | |
| -2- "Have we (America) been able to make engines comparable for power output with the Rolls-Royce or Napier of England?" - "No, but we have tested a Rolls-Royce engine on the test stand at Langley Field, but it failed after only 17 hrs, and we understand that the tests we employ for our engines are more strenuous than the British." "We think that some of these high powers which they claim are only obtainable for short periods". The report went on to ask whether it was thought advisable to enter some of the international competitors with the object of accelerating development. It was further considered inadvisable on the grounds of economy, and they thought they ultimately arrived at the same result but it took a little longer. I have since seen the Buzzard to which they appear to refer, and find the failure was in the supercharger gears. Visit to Langley Field. On Jan. 18th I spent a most instructive day at Langley Field with Mr. Reid and Mr. Kemper. They were very open and I was able to obtain some interesting information. Compression Ignition Development. All done on single cyl. units. They had two units devoted to 4 cycle C.I. work. On one unit no attempt was made to obtain turbulence, while the other was for max. turbulence. The non-turbulent head was circular and flat with the valves working horizontally (Figs. 1 & 2). The nozzle sprayed into the chamber in a fan shaped form. Six spray holes. They run this engine boosted 6" Hg. at 2000 R.P.M. 12.5/1 comp. ratio. 600 lbs. max. pressure. 6000 lbs. ign. press. They get 122 lbs/sq.in. B.M.E.P. after subtracting boost to 6" Hg. The injection pumps are Krupps and they are better than the Bosch. The turbulent head model was similar to our own and recesses cut in piston for the valves. I did not notice any special scheme to promote turbulence. The spray nozzle in this case was in the side of the cylinder head. So far they had obtained the best results with the first model. They thought better results would be obtained if they could get a little turbulence in this head. | ||