+20 = 79.5 mm GPM, cpl.
compr. ratio 9.4:1
Made by GPM
Middle gudgeon pin to lowest point of piston: 29 mm
Middle gudgeon pin to highest point of piston: 41,5 mm
Gudgeon pin diam. 19 mm
can be used f. Norton
Piston Clearance 0.12mm or 45thou
with Piston Rings, Gudgeon Pin and Circlips
Amal Carburettor Body used. Ajs/Matchless 500cc single 89N/IED Bor at flange side 28.5 mm distance of holes at flange: 50 mm Bore opposite flange: 29 mm bore on top 33 mm 1954