1928 Sunbeam Model 8, 350 cc. Registration number PP 7991. F...

Hammer

£10,700

1928 Sunbeam Model 8, 350 cc. Registration number PP 7991. Frame number C1391. Engine number 273/23250.
Sunbeam had begun experimenting with overhead valves on their factory racers in the early 1920s and these duly appeared on production models in 1924. The new 500 roadster was known as the Model 9 while its race bike counterpart, which could top 90mph, was accordingly designated the Model 90. The 350cc versions were the Model 8 and Model 80 respectively. The John Greenwood design was advanced for its day, with a specification which included a crankshaft supported by three ball-bearings, dry-sump lubrication, and primary drive enclosed in a cast alloy chain case. Power was transmitted by single-row chain to a three-speed, 'cross-over drive' gearbox with offside power takeoff.
The overhead-valve models' frame and cycle parts, which had much in common with those of Sunbeam's larger side-valve models, evolved slowly. Sunbeam missed the industry's virtually wholesale switch from flat-tank to saddle-tank frames for the 1928 season, and a saddle-tank version of the Models 8 and 9 did not appear until September of that year. Changes to the overhead-valve engine were confined mainly to its top-end. The early flat-tankers featured a straight-ahead exhaust port, a peculiarity which necessitated the adoption of a bifurcated down-tube. Later on in the 1920s Sunbeam followed the then-fashionable trend to twin-port 'heads before reverting to a single-port design. M9's didn’t get the two port head until 1929, single port heads were an option right through to 1931, then it was two-port only through to 1935. Pushrod enclosure had arrived by 1930 to be followed a couple of years later by partial enclosure of the rocker gear.
PP is a late flat tank example before the change to saddle tank and has Model 1 crank cases fitted. Registered with the DVLA in 1978, it was owned by Ian Young of Gloucester in 2012 before selling it to our vendors father in 2013.
An older restoration it is presented in oily rag condition.
Sold with the V5C.
Please note that this Sunbeam was sold by Bonhams in April 2012 http://www.bonhams.com/auctions/19766/lot/325/