Harley Davidson Evolution Oil Breather

The internal passages on Harley heads need to breathe and the oil drain holes usually found in the corners of the rocker plate must be open and large enough for air and oil to move and drain.

Harley davidson evolution oil breather. The crankcase vented air had to be recycled through the engine. Top breathing engines breath or vent through the top breather bolts which are threaded into the heads of a Harley Davidson motor. Do a leakdown test on it.

Its almost like a whole new engine. From breather hose which eliminates engine oil from collecting. The dark circles between the two sets of arrows are the umbrella valves.

This is an age old problem for the Harley engine. In earlier case breather model engines the oil would pour into the air filter if the bike had been sitting for a few months. On a evo motor with a horseshoe style tank main feed in back and two fittings up towards the front and a factory oil pump two fittings.

8 Aug 12 2019. The air inside a motor is saturated with oil. Timed breathing was introduced on the.

Engine Breather Oil Collector designed to collect the oil mist. My 96 Softail is puking massive amounts of oil from the breather tube. Harley Evolution Engine Breather Diagram Pii Organisedmum De Harley Davidson Oil Pump Diagram Wiring Schematic Diagram Harley Evo Oil Line Fitting Creativehobby Store.

Joined Dec 25 2012. HARLEY engines excluding early engines with total loss oil systems manufactured up until 1999 used some form of timed breathing to scavenge oil from the crankcase and deliver it to the vicinity of the return oil pump so that it could be sent back to the oil tank. The bottom arrows are pointing to the vent that goes to the breather bolts.