Crankcase after a crack test, detailing nine cracks found and recommending repair.
| Identifier | ExFiles\Box 132\3\ scan0063 | |
| Date | 24th December 1936 | |
| - C. to Rm. {William Robotham - Chief Engineer} Lodge jw T 216. 24.12.36. B.17 UNIT. Report on Crankcase after Crack Test. Crankcase No. EB.1697 modified to Ex.18253 (top half). Fitted 13.9.36. Has done 119 hours of test-bed running, 20 hours of which were at 1/2 load 4,000 - 4500 R.P.M., 40 hours of which were at full load 4,000 - 4,500 R.P.M. Has run 22,000 miles on road in chassis B.23 AE. On examination after chalk-crack test, the above crank-case was found to be cracked in 9 places, though the cracks are small, the worst being at the radius adjacent to No.4 bearing-housing on the offside (See drawing Ex.I.103). The bearings affected are No.1, on the near side;* No.4 both sides and No.7 both sides. Cracks are apparent in the bores of No.4 and No.6 cylinders as indicated in Ex.I.103. A crack has also occurred near one of the holes adjacent to the second front engine support on the near-side flange and extends from the edge for approximately .100" (Ex.I.103) Attention is drawn to the fact that all these cracks bear a marked similarity in positions and characteristics to those found in crankcase Ex.19357 ex B.3 unit, a report on which was issued 4.12.36. (RHC {R. H. Coverley - Production Engineer} /HPS. {Horace Percy Smith - Experimental Factory Mgr} 1/EP {G. Eric Platford - Chief Quality Engineer} ,3.12.36.) This crankcase is not badly distorted however, and is to be built up and used again. *Not shown on Ex.I.103. The crack is in the same position as that on the near side of No.4 bearing housing, but is slightly smaller. Herewith Ex.I.103. R. {Sir Henry Royce} Hollingworth. | ||
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).