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).
Page detailing foundry practices for metal casting, including material specifications and process controls.
| Identifier | ExFiles\Box 174\2\ img094 | |
| Date | 27th March 1937 | |
| (sheet 4) (2) Avoid wax vents as far as possible. If necessary draw a lace round pegs if regular wire scheme cannot be used. (3) Avoid localisation of gas by using vents of progressively increasing area in proportion to gas flow. (4) Large head on runners and risers helps considerably in reducing porosity. (5) Buick pour down to 2550°F and not above 2750°F using a mixture containing 20% steel scrap, e.g. forging flashings, remainder Meri Iron. Silicon 2.3 to 2.45% Sulphur .126% Phosphorus .168% Nickel .25% Chromium .30% Total Carbon 3.4% Manganese .67% Excess carbon keeps up the porosity, but if the Si. and C. get too low and the metal fluidity too critical to temperature add a little Ni. and Cr.{Mr Cra???ster / Mr Chichester} (6) Buicks use 14 different mixes of cure sand. The particular variety for jacket cores is as follows:- 150 gallons sharp sand. 30 gallons bank sand. 22 pints of 60% linseed base oil. This gives a tensile of 175 to 200 lbs sq.inch on baked briquette. (7) Tie bars between barrels minimise distortion. (8) It is sometimes customary to paint weak core sections with oil for which purpose a semi-dextrinated corn flour called Mogul oil is used. Excess of oil however will burn through the iron leaving a streak of carbon which looks like a fine hair line behind it causing a leak. (9) The use of chills is considered beneficial if carefully graded to the requirements of the case. In connection | ||