Choosing the correct engine oil for the C-series six-cylinder engine is essential for protecting the seven main bearing crankshaft and all internal components. Castrol Classic produces a range of oils formulated specifically for classic vehicles, available in monograde and multigrade grades to match the original manufacturer's recommendations. Classic XL 20w/50 is a low-detergent multigrade oil suited to the majority of MGC engines in normal road use, providing good protection across a range of ambient temperatures. XL30 monograde is appropriate for warmer climates or where a single-viscosity oil is preferred.
For high-performance or competition use, Castrol Classic R40 castor-based oil offers exceptional protection at elevated temperatures with its distinctive aroma, while Formula RS 10w/60 fully synthetic provides the ultimate in modern oil technology for classic engines. Running-in oil should be used as a first fill following engine reconditioning to allow new bearing surfaces to bed in correctly. All oils are available in 4.5-litre containers, with XL 20w/50, XL30, and Formula RS also available in economical 25-litre drums supplied with a one-pint jug and drum tap.
Engine Paint
Four engine paint colours are available in synthetic enamel: Black, Red, BMC Green, and MGC Green. The correct colour for the MGC engine is MGC Green, a pale silver-grey-green that is distinctly different from both the maroon red of the MGB B-series and the darker BMC Green used on other BMC applications. When refinishing an engine, the MGC Green should be applied to the engine block, cylinder head, rocker cover, timing cover, sump, and engine-mounted ancillaries including the oil filter housing and starter motor. The very earliest cars, approximately the first 100 produced, had the rocker cover in crackle black rather than the body colour, but this is a rare exception.
Jointing Compound
Wellseal jointing compound is recommended for use during engine assembly where a non-hardening, non-flammable sealant is required, particularly at the timing cover, sump, and water manifold cover gasket faces where a belt-and-braces approach to sealing is prudent.
Castrol Classic Pouring Jugs
Castrol Classic pouring jugs are available in half-pint, one-pint, and two-pint sizes, or as a set of three. These are a practical workshop accessory for decanting oil from the 25-litre drums during servicing.