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).
Test report comparing the 'Kestrel' two-piece cylinder construction with the standard version under various conditions.
| Identifier | ExFiles\Box 179\3\ img106 | |
| Date | 31th March 1932 | |
| ORIGINAL To R.{Sir Henry Royce} From Hs{Lord Ernest Hives - Chair}/Lov.{Mr Lovesey} c. to Sg.{Arthur F. Sidgreaves - MD} Por. c. to RE. S. c. to Dy.{F R Danby} EP.{G. Eric Platford - Chief Quality Engineer} c. to Lr.{Mr Ellor} c. to Mr. Jaques. Hs{Lord Ernest Hives - Chair}/Lov.{Mr Lovesey}1/WJ.31.3.32. x3866 'KESTREL' TWO PIECE CYLINDERS. We have now had a fair amount of running experience on the test bed with the two piece cylinder construction and collecting the results we are able to make a comparison between them and the standard construction. Water flow tests under ordinary water cooled conditions shew that the flow through the two piece head is appreciably less than with the standard block and comes below the required A.M. specification with the standard water pump. Under evaporatively cooled conditions the increased resistance to water flow is shewn up very markedly by the formation of steam pockets which in a recent test has resulted in the cracking of four of the cyl. heads between the exhaust and inlet valve seats. This test was made in connection with thermo couple experiments for obtaining the temp. of various parts of the cyl. head. On the particular engine used, one standard block and one two piece block was employed, but the thermo couples were fixed only in the standard cylinder block. The test consisted of running evaporatively cooled and on examination of the blocks after running it was found that the cracking between the valve seats had occurred on the two piece block only, the standard head being in good condition. Under evaporatively cooled conditions the water flow reversal takes place at a higher speed - being 1600 R.P.M. instead of 500 RPM. on the standard blocks. Running under severe detonation on Std. D.T.D. fuel - detonations audible at 100 ft. - the top joint ring was destroyed in precisely the same way as was shewn on the 'R' engine. We have not made a direct comparison under these conditions with the standard cylinder block. Under more moderate detonations - audible at 50 ft. - there was not much difference between the top joint of the two types of cylinder block, but it was thought the 'two-piece' looked in a little better condition. There was, however, no failure in either case. Results shew that the two piece block in its present form with its high resistance to water flow, is unsuitable for running under evaporatively cooled conditions. We must accept that the normal water cooled engines when in service | ||