Patent ID: 7287372

Claim:
A method of adding unburnt hydrocarbons to exhaust from at least one combustion chamber, comprising the steps of: positioning a mixed-mode fuel injector operable to inject fuel into a combustion chamber in a first spray pattern with a small average angle relative to a centerline of the combustion chamber and a second spray pattern with a large average angle relative to the centerline of the combustion chamber; injecting an amount of fuel in the first spray pattern into a non-combustible environment within the at least one combustion chamber during at least one of an expansion stroke and exhaust stroke; moving exhaust with the unburnt amount of fuel into an exhaust passage via an exhaust valve; injecting, for combustion, a first amount of fuel in the first spray pattern when the at least one combustion chamber is in a non-auto ignition condition; and a step of injecting, for combustion, the first amount of fuel in the second spray pattern when the at least one combustion chamber is in an auto-ignition condition.