How many times can rod and main bolts be torqued?

krazykuda said
I don't totally agree with their write up.


They recommend throwing away a bolt that has a .001" of permanent stretch. EVERY BOLT GETS .001" OF STRETCH WHEN TORQUED PROPERLY.


Their way of measuring bolt stretch is not accurate. They say to use a "bolt stretch" gauge when you tighten the bolt/nut. this method also gives elastic and plastic deformation. Elastic deformation will go back when the load is taken off. Plastic deformation is permanent stretch and can only be measured when the bolt is not tightened, before you tighten it, and then after it has been loosened. You can't determine the amount of plastic deformation by measuring the bolt length under load. ...
Click to expand...

In the above, you are talking about ARP recommending replacing bolts with .001 plastic deformation. Then right after you talking about elastic deformation, which does not count towards plastic deformation.

Quality rod bolts have a smooth barrel, typically not a knurled shank, that is pressed into a bore of the rod which centers it in the bore. The cap is then installed centering itself, on the two rod bolts. This is as precise as you can produce a rod. Quality rod bolts have spherical "dimples" on both ends of the rod bolt which index the micrometer or stretch gage.