Bottom End Assembly Rod Bearing Orientation Question

[Thumperbird]

I think I know the answer to this but thought I would check.
Does rod bearing orientation matter in terms of the larger bearing chamfer with respect to large radius side of rod/crank or towards rod center?
 I don't think I paid attention to this when I first assembled engine a few years ago.  I noticed 6 bearings had a larger chamfer on the side closest to the registration tab and 10 were the other way on the removed set from the old days.  The new set of bearings appears to be 8 larger chamfers closest to registration key and 8 on opposite side, so technically I can install them as top and bottom sets so to speak with larger radius towards crank in all cases or towards center.  Wondering it if really matters though, I have plenty of side play either way so no interefence sideways.  Preference for oiling or ?
Just curious.  Thanks.

[blykins]

If it's a stroker with BBC rods and performance bearings, the bearing shells will either have a "U" or an "L" on them.  One goes to the upper side, the other goes to the lower side.

[Thumperbird]

Yes it is.  Crap, how dumb of me, glad I asked, must have forgotten, had them opposite of course, oh well, more practice with dis-assembly and assembly.  Thanks Brent.

[Thumperbird]

So of course I installed the bearings correctly now but visually see no reason for U and L in this case for rod bearings.  Does anyone know what the difference is and why, just curious.  General reading says it is to put large chamfer on crank side for clearance but the chamfers on the bearings vary some and that area has tons of clearance regardless, at least on the SCAT crank and rod setup I have.

[My427stang]

Some you have plenty of room, some you don't. So, if you had the clearance, U and L doesn't matter, but I sure wouldn't want the next guy to take one apart with my name on it like that! 

Regardless, depending on the crank, and likely some bearing/rod tab machining difference, sometimes they can touch.  I rescued a 496 last year that didn't work, it used standard width bearings and they kissed even in the correct configuration.  A set of narrowed ACL and it was very happy

Much easier to put in the right place AND check that you are inside the rod chamfer AND that the rod is on correctly

[Barry_R]

F-M race rod bearings have the wider and narrower chamfer - the wide side faces the crank counterweight.  Clevite race bearings are "narrowed" and don't show a significant chamfer.  Instead they use the locating notch to move the narrower bearing to the side a small amount, providing chamfer clearance.  Passenger car bearings do not provide more chamfer clearance and sometimes the work, sometimes they edge load, and sometimes they just bind up on stroker cranks.