Abstract: A “pencil” ignition coil includes a seal member having features that cooperate with complementary features provided on the engine cam cover/spark plug well into which the coil is inserted to provide a retention and tactile feel insertion feature. In particular, the cooperating features are configured to longitudinally align and position the ignition coil in the spark plug well in a predetermined relationship. In one embodiment, the seal member includes a circumferentially-extending rib on an outside diameter thereof, while the cam cover/spark plug well includes an undercut groove portion on an inside diameter portion thereof. The rib has an increased diameter relative to the surrounding, outside diameter surface of the seal member, while the undercut groove portion has an increased diameter relative to the surrounding land portions.

Abstract: An ignition apparatus includes a magnetic circuit comprising a central core and a side core or shield, and primary and secondary windings. The shield is allowed to electrically float, thereby reducing the capacitance of the secondary winding. A housing is external to and surrounds the shield to inhibit arcing. A silicone boot overlaps a housing/case interface to further suppress arcing.