I'm in the process of checking my main bearing clearances. The inside diameter is coming out between 2.4525" - 2.4530" on all 5. These are Fed-mog. 139M STD size. I'm using a dial bore gauge to check and I'm pretty confident in my measurements. The block was line-honed because I'm using studs and the empty bores are right on the money. They are consistantly on the large side, so I'm thinking I just got a bad set? Any other opinions? These seem way outa spec to me.

Next question (which might seem kinda of trivial): A 350 chevy has a nominal 2.450" journal size. When a bearing manuf. says "STD size" what should the final inside diameter be (dimensionally)? And what is the tolerance on std sizes? 2.45xx +/- 0.000x ??

Thanks.

 

off the top of my head the main diameter is 2.248-2.249 with no more than .003 oil clearance.

 

Ede, my crank journals are within that spec, nice and round with no taper. I was thinking about it more last night and I think I might have torqued my caps incorrectly when I was test fitting. The studs call for 70 ftlbs with assembly lube or 80 ft lbs with 30wt. I think I mixed it up and only went 70 ftlbs with the 30wt. So I might not have had the bearing seated all the way. Also, I'm going to get a .001 undersize set to see if that helps.