The Tadek Marek-designed inline-six features an aluminum block and cylinder head, with the latter topped by dual overhead camshafts.The engine was sent to Motorman Engineering of Hertfordshire, England, in 2002 for a rebuild at a cost of £20k and included a displacement increase from 3.7 to 4.2 liters.The block was machined to accept 4.0-liter cylinder liners, which were in turn bored and honed for a further increase of 0.2 liters before installation of correspondingly sized forged alloy pistons.The cylinder head was overhauled with Tuftrided stainless steel valves, hardened seats, and performance camshafts. Triple SU carburetors replaced the two-carburetor factory setup.An electronic ignition system was also added, and the electrical system was converted to negative ground.The carburetors were adjusted in 2016, while the ignition system was refreshed in 2019.The five-digit odometer shows 29k miles, total mileage is unknown.