Piston rod bearings on a Farmall A C113 engine

Let me start by saying that I am a complete novice to measuring bearings and engine parts. I have disassembled a C113 engine and am trying to determine what size bearings that I need to order. I have the IH8 Farmall shop manual which says that the crankpin diameter should be 1.7495. My crankpins measure (all four of them) to be 1.7200 as measured with dial calipers. So what bearings should I choose as replacements? Am I doing this correctly so far?

Thanks,

MACE

Thanks for all the advice so far fellers...

MACE

That thought did cross my mind about the crankshaft being ground down. When I got into the engine, I found the crankpins to be in very good shape as far as I could tell, they look as if it is new crankshaft. The measurements are the same on all crank pins. I measured in three locations on the outsides and in the middle and came up with the same measurement. I noticed that someone had been in the engine before me due to the blue cylicone sealant in the engine. When I got the tractor, the rods and pistons had been removed. Thank you for the advice so far and for the tip to look at the bearings themselves. The bearings did not look in bad shape at all. The pistons were removed due to wear and from what I could tell some scoring on one of the cylinder walls. I notices that a chunk, about 1/2 square inch, of one of the cylinders was missing and assume it was drained out with the oil as I have cleaned the entire engine and found no metal. Do you think that I may be able to take a plastiguage and measure my clearances? If they coinside with what the book says, then my bearings may be ok. I would rather put new ones in, but I may have trouble finding the ones that I need.

Thanks,

MACE

If you use new bearings, you will have to plastigage them too. Check with your local IH dealer for +0.030" bearings. They should be easy to find.