1973 Seeley Mk4/G50, 496cc. Registration number not register...

Hammer

£9,700

1973 Seeley Mk4/G50, 496cc. Registration number not registered, Frame number MK4 CS 359N. Engine number RLE 18 (Ron Lewis Engineering). Gearbox N 11763 (Schafleitner).

British sidecar champion Colin Seeley bought AMC racing department when the company went into receivership in 1966. In 1965 year he had constructed the first Seeley frame to house a G50 (500cc) engine, and the purchase enabled him to produce complete Seeley G50 and 7R machines. Each frame was recorded in his ledger.

Before long, the basic Seeley design was being wrapped around other types of engine: Norton Commando twin, QUB single, Yamaha TD/TR twin, URS four, and the Suzuki TR500 twin.

The frame progressed from the duplex cradle original to the similar but lighter Mark 2 before the down-tubes were abandoned with the Mark 3, the headstock and swinging arm pivot of which were linked solely by tubes running diagonally above the engine.
Introduced in May 1971, the Mark 4 featured a revised tubing layout and continued in production until 1973.

Only around 180 original G50s were built in AMC's East London Plumstead factory during the five years of production, from 1958-1963, developed from the AJS 7R, the original stroke of the 7R was kept, combined with a wider bore of 90mm which gave 496cc. It kept the same basic architecture, with magnesium crankcases and cam chain covers highlighted with corrosion-inhibiting gold paint. This paint has given rise to the nickname “Golden Eagle”.

According to the Seeley ledger, 359N was finished by Colin on the 16th February 1973, probably just as a frame as there is no name listed against the frame number in the inventory book. The N relates to Norton as Commando engines were a common fitment although whether this was what was originally fitted we cannot be sure.

Our vendor bought it from Bill Smith Motors of Chester in the winter of 1977/78 and was told it had belonged to Dave Gandy of London. It has the following features; 1960 Matchless G50 engine with Ron Lewis Engineering alloy crankcases, Carrillo conrod and Cosworth piston, the 5 speed gearbox is by Peter Schafleitner and was overhauled by Ray Petty in 1984, AMC 3 plate clutch, Lucas 2MTT magneto, 1 ½” GP” carb, 11” front brake and Manx drum rear. After its last race in 1986 the oil was drained and it was put into storage. He raced it Nationally at such circuits as Oliver’s Mount, Oulton Park, Sntterton, Cadwell, Donnington, Mallory Park, Aberaman, Aintree, Croft and Knockhill.

Offered with the following spares; new piston with rings, used piston with rings, GP2 carb parts, various engine spares, bearings, sprockets, valves, cables, steering damper, rear wheel sprockets and engine and gearbox information, together with the Seeley Authentication letter dated 11th May 2022.
A rare opportunity to be the next custodian of a very original race machine now in need of recommissioning.