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).
Experimental Bentley cylinder block and head castings, detailing casting defects and dimensional inaccuracies.
| Identifier | ExFiles\Box 86\1\ scan0251 | |
| Date | 31th August 1937 | |
| 219. LHTHS Pilee SWDL{Len H. Swindell} To Mr. [redacted] from HPS.{Horace Percy Smith - Experimental Factory Mgr} c. to Rm.{William Robotham - Chief Engineer} c. to Mr. Vickers (Iron Foundry) HPS.{Horace Percy Smith - Experimental Factory Mgr}7/VS.{J. Vickers}31.8.37. BENTLEY CYLINDER BLOCK AND HEAD TO LeC.5717. The Iron Foundry have recently supplied us with two of the above cylinder blocks, which were designed with the object of reducing the percentage of scrap castings. The difference between these and the standard cylinder block is as follows :- 1. Core inspection covers moved outwards to a position between the cylinders. 2. Openings provided in the transverse webs on the inlet side to allow a vent pipe to run straight through the sand. 3. Additional facings for water pump connections. 4. Two additional core plugs on the exhaust side. 5. Four additional plugs in floor of casting for venting. 6. Modifications to sand cores for cylinder head. 7. Additional core inspection plugs in top of jacket. On machining the joint face of the casting, porosity was observed adjacent to the bores; this subsequently caused leakage on water test. Since this block was unsuitable for service, it was sectionalised and passed to the proof inspector, whose report is as follows :- "The cylinder barrels in the core are slightly misplaced and .062 oversize on the 3.825 dia. The thickness of the top floor of the tappet core is plus .125 and the bottom is minus .080. The core in the end section is .075 short on the 2.500 dimension from the cylinder bore. continued. | ||