Tappets

[Bob Culver]

For anyone perplexed by the very wide clearances adopted for most makes post the Seven, this is because of opening and closing ramps designed to quieten and soften openings and closings and to reduce the effect of slight clearance variations on accelerations/decelerations. To avoid the vagueness associated with the ramps a wider clearance is usually stipulated for setting timimg and this confuses comparisons with Sevens.