A method of removing oil from blowby vapors in an engine having a crankcase and an intake manifold includes filtering the blowby vapor from the engine crankcase to form a vapor depleted of oil and a collected oil. The vapor depleted of oil is communicated to the engine manifold. At high engine loads the collected oil is held in a chamber, and at low engine loads while the engine is still running, the collected oil is forced from the chamber back the crankcase.

A utility vehicle includes: an engine which is a drive source; a catch tank configured to perform a gas-liquid separation of a blow-by gas generated in the engine; a first breather passage configured to deliver the blow-by gas, which is discharged from the engine, to the catch tank; a second breather passage configured to supply a gas component, which has been separated in the catch tank, to an air intake system of the engine; and a return passage configured to return a liquid component, which has been separated in the catch tank, to the engine. The catch tank is disposed above a cylinder head covering. A breather outlet port, with which the first breather passage is fluid connected, and an oil return port, with which the return passage is fluid connected, are formed in an upper surface of the cylinder head covering.

An oil and air separator includes a first housing including a central chamber therein, the central chamber divided into a first outer portion and a second inner portion by a barrier; a filter material disposed between the first outer portion and the second inner portion; a cap directly coupled to the first housing, the cap including a first lumen therethrough, the first lumen including a first end disposed at the second inner portion; an extension portion including a second lumen therethrough; and a coupler removably coupling the cap and the extension portion.

A method of removing oil from blowby vapors in an engine having a crankcase and an intake manifold includes filtering the blowby vapor from the engine crankcase to form a vapor depleted of oil and a collected oil. The vapor depleted of oil is communicated to the engine manifold. At high engine loads the collected oil is held in a chamber, and at low engine loads while the engine is still running, the collected oil is forced from the chamber back to the crankcase.

A method of removing oil from blowby vapors in an engine having a crankcase and an intake manifold includes filtering the blowby vapor from the engine crankcase to form a vapor depleted of oil and a collected oil. The vapor depleted of oil is communicated to the engine manifold. At high engine loads the collected oil is held in a chamber, and at low engine loads while the engine is still running, the collected oil is forced from the chamber back to the crankcase.

An engine includes: a cylinder block that has a cylinder included in a combustion chamber; a crankshaft that is placed in the cylinder block; a flywheel that is mounted to one end portion of the crankshaft; and a flywheel housing that is placed on a side of one end face of the cylinder block in a direction of the crankshaft and that houses the flywheel. The flywheel housing has a blow-by gas path through which a blow-by gas passes.