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IH: Oiling & Lubrication
Engine Oil Routes
Right Crankcase Feed Galley
Top End Oiling
Rocker arm / Valve oiling
Rocker Box Oiling
Oil travels in a passage between the two rocker arm shafts (big end).
The oil line comes from underneath into one shaft bore on the pushrod side in each rocker box.
There is a rifle drilled hole between the rocker arm shafts in each box that connects the two for oil passage.
Each hole is plugged off on the outside of the box.
Rocker Boxes on 69 model. 1) | |
Bottom End Oiling
Pinion shaft and Crank Pin
Cam Cover Bushings
Cam Cover \ Gasket
Case Oiling and Drainage
Splash
Oil Pump Scavenge
See also the IH Oil Pump section of the Sportsterpedia.
'77 and Later Cases
The “drain plug” on the bottom of the case is simply a threaded plug that caps the oil scavenging passageway. 2)
The MoCo drilled from the bottom of the case to the horizontal oil passage in the gearcase.
This connects the crankcase sump oil to the scavenge port of the oil pump and the hole is plugged on the bottom.
From inside the case with the plug removed from the scavenge passage;
In the second pic below, you can see that the threads, from the tap, have been machined farther up into this hole.
This is the oil passage from the sump to the scavenge pump.
Oil from cylinder drains, crankpin, pushrods and cam chest that collects in the sump is fed to the pump by crankcase pressure and pump suction through this hole.
Case Drain Plug on a 1977 engine 3) | ||