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).
Technical document detailing engine core venting methods and dimensions, with a comparison to Buick's production techniques.
| Identifier | ExFiles\Box 174\2\ img059 | |
| Date | 27th March 1937 | |
| (sheet 2) E.1/HP.27.3.37. quantity, two complete layers of wires being used, one above and one below the ventilating galleries in the larger portion of the core. Diagram Annotations: - 3 VENTS 1/2 DIA - GALLERY VENT 3/16 DIA - (4 VERTICAL VENTS 5/16 DIA. FLATTED TO CONTACT 3/16" WIRE) - 3/4" CORE THICKNESS - LOOSE PIECES-COME AWAY WITH SAND - 1/8 CORE THICKNESS - 5/32" TO 3/16" CORE THICKNESS. - PEGS ON STRIP PUT IN LAST. The venting passages were made by putting in plugs and wires and then pulling out before baking. The perspective sketch shows how these interlock. Wax vents are never used on Buick production. They are considered to be too late in action to be of much real use, and are thought to make a lot of gas themselves, which has to be driven out of the core. Buick endeavour to arrange a vent out of every section possible, and avoid localisation of vent pressure by progressively increasing the vent area in proportion to the expected gas flow. The 8 in-line core shown above has a sufficient variety of core thicknesses between barrels to indicate that the only limit is the thickness that the sand will hold up to. We have since heard of an example in production where this is only 1/8". | ||