Blow-by gas passage system for internal combustion engines

For use with a multi-cylinder internal combustion engine having a crankshaft, crankcase, a cylinder block and a cylinder head, the improvement comprising, in combination:

• two blow-by gas passages formed on one side of the cylinder block and cylinder head and spaced longitudinally of the crankshaft, said blow-by passages each communicating with the interior of the crankcase and extending above an upper face of the cylinder head, a first of said blow-by passages being provided with a mounting port, a baffle at the lower end of said first blow-by passage to restrict entry of gases and splash oil from the crankcase, an oil separator carried on said mounting port, means connecting said first blow-by passage to said separator, and means connecting the separator to the intake system of the engine.

A blow-by gas recovery system for a multi-cylinder internal combustion engine having a crankcase, a cylinder block, an intake system, an oil separator, and a cylinder head with overhead valves and a breather, the improvement comprising, blow-by gas passage means formed in the cylinder block and cylinder head for communicating the interior of the crankcase with the interior of the cylinder head, said blow-by gas passage means opening into said cylinder head at a location to inhibit the entry of lubricating oil in the cylinder head, oil drain passage means formed in the cylinder block and cylinder head for communicating the interior of the cylinder head with the interior of the crankcase, said oil drain passage means opening into the cylinder head at a location for promoting the drain of all the lubricating oil from the cylinder head, said blow-by gas passage means including at least one passage extending between the crankcase and cylinder head and having means connected to the oil separator, and means connecting the oil separator and breather to the intake system of the engine.