An assembly for cleaning blowby gases has an electric heater and a
downstream catalyst positioned in series relationship in a blowby conduit
leading from an engine's crankcase to the atmosphere. The heater is
controlled by a controller to maintain a selected temperature at the
inlet to the catalyst as determined by a temperature sensor. The heating
of the blowby gases increases the blowby gas temperature to a level where
the catalyst is active to oxidize the constituents of the blowby gas
stream.