The Engine Tuning catalogue covers the bolt-on parts that allow owners to extract more performance from the original engine architecture of a classic MG without straying into full competition territory. The aim is informed, sensible tuning, keeping the car driveable, reliable and pleasant on the road, while unlocking the headroom that the standard production setup deliberately left on the table. The catalogue covers performance carburettors, oil coolers, timing gear and uprated head gaskets, with the dedicated Performance Engines sections covering more comprehensive stage-by-stage engine rebuilds.
Performance Carburettors
Performance Carburettors cover the larger-bore SU and Weber options that suit a tuned B-Series, A-Series or C-Series engine. The standard MGB twin 1¾-inch SU HS4 carburettors are well suited to the original 95 bhp specification but become a restriction with anything more than mild head and camshaft work; the move to twin 1¾-inch HIF44 or to twin 2-inch HS6 carburettors releases the flow needed to support a Stage II or Stage III head. Weber 45 DCOE sidedraught options are stocked for owners going further, typically for cars used regularly on track or for sustained fast-road use, along with the appropriate manifolds, linkages and jet selections. The same principle applies on the A-Series Midget cars, where the move from twin HS2 to twin HIF38 carburettors is the standard route into mild tuning.
Oil Coolers
Oil Coolers were originally factory-fitted to many MGBs and MGCs but became less universal during the rubber-bumper era and were sometimes deleted by cost-conscious owners during restoration. They are emphatically worth refitting. A classic engine running hard on a UK summer day can shed considerable heat through the oil rather than the coolant, and oil temperatures of 110°C and above accelerate viscosity loss, oxidation and bearing wear. The catalogue covers complete cooler kits with the radiator core, flexible braided lines, take-off adapter and mounting hardware, sized appropriately for the engine concerned.
The standard 13-row cooler suits a near-standard MGB; larger 16-row and 19-row cores suit tuned engines and the MGB GT V8.
Timing Gear and Uprated Head Gaskets
Timing Gear covers the duplex timing chain conversions and the adjustable vernier camshaft sprockets used during a performance engine rebuild. The original single-row chain on the B-Series engine stretches with mileage, allowing valve timing to retard and progressively dulling response; a duplex conversion gives much greater longevity and consistent timing. The vernier sprocket allows the cam to be timed precisely on assembly, essential when a non-standard camshaft is fitted, where the standard timing marks may not give optimum results. Uprated Head Gaskets cover the multi-layer steel and composite-fibre gaskets used in tuned applications, including the V8-spec gaskets needed for the higher cylinder pressures of a hot Rover-derived engine.
The cross-references between the Engine Tuning section and the dedicated Performance Engines sections, in the Performance Engines section, give the full picture for owners planning a complete engine rebuild rather than a bolt-on upgrade.