I have a question that relates to measuring for oil clearance for main and rod bearings. I understand you are supposed to torque them to spec to measure for clearance on both rods and mains. However I thought main bolts as well as rod bolts were only supposed to be torqued one time ? Doesn't this stretch the bolts and when retorquing the bolt wouldn't it be inaccurate ? Or will the bolts go back to size ? How does this work when torquing using rod bolt stretch ?

 

Bolt torques specs are actually low on engines compared to what it will take to actually stretch the bolt/stud, you'll be fine.

 

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Some fasteners are designed for elastic region stress/strain (i.e. plastic region is where they don't take on any permanent stretch) like rod and main bolts and can be reused. Some are designed for plastic region stress/strain (i.e. do take on some permanent stretch) like head bolts and shouldn't be reused. Check the repair manual, if it says replace then most likely the fastener was a plastic region type bolt.