318 connecting rods

You oftentimes see manufacturers give rods a horsepower rating, and that may apply for cyclic beam loading. But I’ve never bought into it as an accurate means of rating. Piston mass and stroke are the greater factors. Steel, like most other solids, is much stronger in compression than in tension. So the piston pulling against the rod and angular thrust loads impact rod life (especially the bolts!) more than the vertical thrust that happens in the first 45 degrees of crank rotation from TDC power stroke. Of course, it’s more viable in the case of supercharging or alcohol usage. And if you’re burning nitro, you’re foolish if you don’t have aluminum rods. But for 99% of us here, the hp rating of a rod is less meaningful than how strong the bolts are that keep them together at high rpm.