I want to make sure I'm reading the crank measurements right

[WH23G3G]

I'm taking some base readings of my main and rod journals before I take it to the machine shop. The rod and main bearings I took out said .010 US. Does that mean .010 undersize or oversize? All the Re-ring kits contain oversize bearings. It seems kinda misleading. Does it mean the specs I come up with should be .010 less than the original specs on my 73 crankshaft which should be 2.6245-2.6255 inches on the mains and 2.374-2.375 inches? Which seems logical to me calling the bearings undersize because .010 has been taken off the journals. I came up with 2.615 inches on the main and 2.363 on the rod journal which is about .010 off the original specs. I stopped measuring because I wanted to make sure I know how to do it. It also makes sense to me that the bearings would be called oversize, because wouldn't the bearings be .010 larger than the standard crankshaft journals. I don't know though, it's confusing. The machine shop will check it for me but I wanted to get an idea in case I might need to find another crank. I've forgotten how to read the micrometer so I had to use a vernier caliper which was coming up with all the same readings at every position I measured on the journals. 

[Challenger340]

2.6245 - .010 = 2.6145

2.375 - .010 = 2.365

Yes, you are correct in your readings, & Math.

When cranks are "reground", they take them to the next "undersize" specification. .010", or .020", or .030" depending upon how much material must be ground "off" to correct the finish.

The Bearings, to "correspond" to the corrected/ground Crank journals, must then, become thicker to make up the difference.

Bob out.

[firefighter3931]

  The "U" stamp designates an undersized crankshaft so the bearings are .010 thicker (than stock)

When you have the crank polished have the machinist leave .0020-.0025 clearance on both the mains and rods. 


Ron