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).
Engine overhaul periods, experimental work at P&W, and a visit to Allison's factory regarding lead bronze bearings.
| Identifier | ExFiles\Box 173\1\ img176 | |
| Date | 20th January 1934 | |
| H.{Arthur M. Hanbury - Head Complaints} S. from R.{Sir Henry Royce} H.{Arthur M. Hanbury - Head Complaints} C. - 3 - 1/20/34. after this period being remarkably good, and few replacements are necessary. They recommend, however, dismantling after this period, in order that all parts can be thoroughly cleaned. Although this period has been laid down, engines in commercial service are running satisfactorily 500 hours between overhauls. Commercial flying companies are endeavoring to force this period. The average life of engines recommended by P & W is 1200 hours, but some engines have seen 2000 hours service. Experimental Work P & W state that they spent between $500,000 to $600,000, which equals £100,000 / £120,000 Per Annum, on experimental development and research. Since they are not subsidized by the government, this expenditure is borne by the company. THE WHOLE ALLISON'S I arrived Indianapolis Wednesday night, January 17th, and saw Mr. Gilman, Pres. of Allison's next day. Allison's are doing an enormous business in lead bronze production, and anticipate this years out put to range 2,000,000 bearings of various type. It is further expected that lead bronze will be introduced as standard on all cars next year. Contrary to what we had been told lead bronze has not yet been standardized on any cars, although most manufacturers have a number of cars fitted with lead bronze, which are being tested out with view to standardization. Reports Mr. Gilman has received on lead bronze bearings are so satisfactory that it is anticipated that lead bronze will entirely replace white metal within next twelve months. I gathered during my conversation that he did not feel too confident with regard to tests for R R bearings. He severely criticised oil grooves and low oil pressure, and emphasized importance of correct lubricant. Unsuitable oil causes lead to disintegrate, Castrol oil being quite unsuitable. Mineral oil, however, is considered to be satisfactory. Oil pressure is important, minimum pressure being 100 pounds □ inch. Normal pressures in use are 100 LBS □ Inch pound bearings at 90° inlet temperature with groove bearings for center bearing in particular. It may be considered worthwhile to be testing out bearings of this type having 6-8 oil feed holes (see sketch). Allison's state that with increased oil pressure it is possible to reduce bearings clearances, but that they were non-commital regarding what revised bearing clearances should be. This, however, can be determined at Derby by test. Progress of tests is rather disappointing, owing to labor restrictions imposed by government. The working week has been reduced to 40 hours, with an embargo on overtime, with a further contemplated reduction to thirty-two hours. I will, however, report when test commences. Allison's are very secretive and have placed a rigid guard on me for the moment. They have arranged for the test in connection with lead bronze to be carried out at the Stutz factory in Indianapolis.(Allison's factory is situated at the Speedway, some distance out of the city). The Stutz factory, which is now | ||