Main Bearing Crush vs. Clearance
Main Bearing Crush vs. Clearance
(OP)
On an automotive type main bearing, how much does the housing diameter effect the bearing clearance. Can I open up clearances by enlargine the bearing housing slightly? Does increasing the housing diameter .001 increase bearing clearance by the same amount? Any info on this would be of great help. I'm in the middle of my first engine rebuild.





RE: Main Bearing Crush vs. Clearance
RE: Main Bearing Crush vs. Clearance
RE: Main Bearing Crush vs. Clearance
Most manufacturers have "graded" bearings available, at least at their assembly plants, and some (Honda, Toyota etc) make these available for aftermarket builds, as do some manufs (aftermarket) for certain V8's, Chevy etc. If available, you can often "juggle" these to get the clearance you want.
Talking of which you should be shooting for 1.5-2 thou for a cooking build, and a little more for perf work, depending on your engine.
Other than that, get the crank resized, after you've mock assembled the bearings you have and established the dimension you actually require. Go to the trouble of giving your grinder YOUR micrometer as well, to make sure you're singing from the same songsheet.
Increasing the housing diameter is just asking for trouble in most cases, and make sure you have a spare block & crank............
John.
"It's not always a case of learning more, but often of forgetting less"