A vapor purifier for oil recovery from and cleansing of deleterious matter carried by oil vapors in a crankcase of an internal combustion-type engine generally includes a coil member that can separate the oil from the vapors by passing the vapors over and/or through the coil member. As the vapors impinge upon the surface(s) of the coil member, oil in the blow-by vapors condenses thereon. The vapor purifier can include a flow equalization member to maintain a normal engine intake manifold pressure for driving modes of the engine. As a result, the vapor purifier of the present invention can maintain the air to fuel stoichiometric ratio of the engine system. Additional components, such as filters and/or disks can also be included in the vapor purifier to promote oil recovery and cleansing of deleterious matter from the vapors, which act as a host for the deleterious matter.