An igniter for ignition over a wide air/fuel ratio range. Igniter includes an
igniter body including an internal cavity disposed substantially within the igniter
body, an internal spark gap disposed substantially within the internal cavity,
an external spark gap disposed substantially on an exposed surface of the igniter
body, and a fuel charge delivery system for delivering a fuel charge to the internal
cavity. A method for compression-igniting an air/fuel mixture in a cylinder of
a internal combustion engine, the method comprising introducing a substantially
homogenous charge of a first air/fuel mixture into a cylinder of the internal combustion
engine during an intake stroke, compressing the substantially homogenous charge
of the first air/fuel mixture in the cylinder of the internal combustion engine
during a compression stoke, and combusting the substantially homogenous charge
of the first air/fuel mixture in the cylinder of the internal combustion engine
during a power stroke by injecting partially combusted products of a second air/fuel
mixture into the cylinder, with the first air/fuel mixture having a substantially
higher ratio, by weight, of air to fuel and the second air/fuel mixture.