Been beavering away on a scrambler build so time for some updates. I’ve had the cam reground to a dual pattern arrangement of my own design (go here). This will take better advantage of the larger 44mm intake valves and the combination has proved to add between 10-15% power. The lifts are not dissimilar to a couple of the other dual pattern cams that are around (7.7mm inlet lobe lift which delivers ~10.1mm at the valve) but some modern curve fitting has allowed more area under the lift curve and a little more duration which will benifit from an increase in compression ratio – the subject of the next post.
Balanced the conrods: the big end of the stock rods were within .1gm of eachother – pretty good but 2gms difference in gross weight so some material was removed from the small end of the heavier rod.
Rods balanced. Ground areas freshly shot peened. New big end shells and bolts :