Description
This is an adjustable cam sprocket for a MGA and MGB 1963 to 1971 with dual row chain. NOTE: It will also fit 1972 to 1980 MGB and Austin Marina by replacing the original single row gears and chain with dual row gears and chain. Cross Ref.# - compares to 460-398
The Vernier dual row camshaft gear has a center which attaches to the camshaft and the outer gear is adjustable. You can loosening the allen bolts, the gear then can be rotated thereby adjusting the camshaft relative to the gear. This method of camshaft timing has two advantages; firstly it makes the task of timing much easier than when using offset keys and secondly it permits further advancement of the timing. Advancing camshaft timing, that is making the full inlet valve lift occur before the rotation angle specified by the manufacturer, will make the engine produce more torque lower down in the rev range while losing a little of the top end power. Thus a vernier cam gear allows a camshaft's characteristics to be changed and adjustment to be perfect.
