by Mike Mavrigian
(Taken from Modern Engine Blueprinting Techniques by Mike Mavrigian)
The torque values below state clamping loads reached with a particular kind of fastener. This chart should be used as guide and not a definitive reference because it does not necessarily reflect the torque value specification for a given engine application. For that, you must follow the engine manufacturer or the fastener supplier specifications.
Always lubricate threads prior to torquing to ensure accurate readings. This chart is courtesy of ARP.
High-quality, high-performance connecting rods are usually packaged in boxes that include instructions regarding bolt torque and stretch specifications based on the particular bolts being used. (This varies depending on bolt diameter, bolt length and specific model of the bolt. This box has torque information (with torque, with moly, as well as bolt stretch specifications).
The opposite side of this rod box also includes a handy data-recording chart that allows you to record torque or stretch data on a per-bolt basis, as well as the number of times the bolts have been tightened.
Caption Some OEM rod bolts (such as this stock LS 9-mm bolt) have a thin metal dowel sleeve that centers the bolt shank in the rod cap. If you’re using OEM rods that have this style, toss the bolts and dowels into the trash and replace them with performance aftermarket rod bolts (from ARP, for example) that offer not only superior tensile strength, but have shoulders that provide proper bolt centering. Incidentally, most OEM rod bolts are torque-to-yield style and should not be reused anyway.