I recently recieved my crankshaft from the machine shop and need to order bearings for it now. I mik'd the crank and all of the rods come out to 2.0791 or 2.0790. Which is good. My question is which oversize of bearings I should buy?

According to the book the crankshaft rod limits are 2.0998-2.0893.
If I then subtract my rod diameter from the service limits I can come up with the folowing:

2.0893-2.0791=.0102
2.0998-2.0791=.0207

See my point? I am at odds with what size bearings to buy, .010 over or .020 oversized. Which "Servicable" limit measurement do I use to make my decision?

 

i think you ought to take another look at your manual, i'd bet the specs on the crank pins are more like 2.0998 to 2.099 which works out to be about .001, not .01. i'm susprised your machine shop didn't stamp the crank and tell you what they did.

 

They said that the rods were ground .020 under, but that is dependant on which measurement you use. So I should use the larger measurement?

 

If the crank journals are .020 undersized, you want .020 undersized bearings.

 

I think you mean I want .020 oversized rod bearings. I believe .020 is correct. I used the data for a 90-94 350 crank. The data for a 86-89 crank is much closer and trustworthy. It is 2.0998-2.0993." So .020 it is.

What measurements does everyone else use?