[Kohnke Rebabbitting]

Any end play clearance over .006 will start oil leaking. You have to seal the shim packs, and both ends of the main bolts. The oil pipe has to be utilized, and has to be clear of babbitt, and excess threaded portion of pipe thread. That is a clean 3/8's hole.

Shaft clearance on a Model A should never be .001, you will remove bearing material, and wasting it, and also take a big chance of smearing the first .010, of bearing surface. When this is done, the outer surface starts moving to fill the oil grooving, and creating an irregular bearing surface. Then the babbitt material that went into the oil grooves, break off and run back through the bearing, creating more bearing disfigurement.

The shaft clearance should be from .001-60, to not over .002-25. When the mains are broke in, they will be closer to .003 clearance, when checked cold. The harder you drive the car, the more the crank expands, the more clearance the bearing will have. The crank when normal Temp., will have expanded at least .001-50 thousandths, so at .001, to .001-50, where is the clearance, for oil?

We set Model A cranks to .002-25.

Also, any Model A crank, including all other engines, of course, has to be dead center of the front, and rear main bolt holes. Many of Model A's, " new Pours ", are off by .010 thousandths, that I have seen. That rubs the Aluminum
slinger on one side, and has a big gap on the other side, to gush oil, and there is only one way to fix it.

Herm.