Summary of Contents for Honda Accord 1994 Service Manual - Page 47

  • Honda Accord 1994 Service Manual - Page 47

    VTEC — Mechanism Al Low Speed: As shown, the primary and secondary rocker arms are not connected to the mld rocker arm, but are driven separately by cam lobes A and a at diherent timing and lih. The hit of the secondary cam lobe is small so that one intalte valve slightly opens lonervalve control). Although the mid rocker arm is Iollewing the cenlev cam lobe wrth the lost motion assembly, it has no effect on the opening and closlng of the valves in the low rpm range PRIMAth sEcoNnARv CAM CAM A c a PRIMARV CAM PRIMARV SECONDARY ROCKER ARM ROCKER ARM A SECONDARV CAM nMING PISTON ‘ A and a cam lobes drive the rocker arms SVNCHRONIZING separately PlsmN a smerR SVNCHHONIIING 51’0 PISTON A At High Speed: When drivmg at high speed, the timing piston moves in the direcllon shown by the arrow In the ligure below. As a result, the primary, secondary, and mid rocker arms are linked by 2 synchronizing pislons (like a skewer) and the 3 rocker arms move as a single unIL In this state, all the rocker arms are driven by cam lobe c, opening and closing the valves at the valve timing and valye lilt set for high operation. MID cAM A c /B MID CAM MID ROCKER ARM HVDRAULIC PRESSURE Connected by hvdraulll: piston, arm driven only by the mm mm 5-6