The Brian Crower BC625+ rod is an H beam in profile. We prefer this profile over I beams because it is stiffer in bending in the way a rod is stressed, but many good rods are designed either way. The pebbly finish is due to shot peening. In shot peening the part is bombarded by steel shot at high velocities. This makes a compressed fine grained skin of metal over the entire surface of the part, sort of like a forged skin. This makes it very hard for a crack to start on the surface of the rod and its fatigue life is improved over 100%. Crower rods are first peened with a smaller shot to get in all the tight places, then hit hard with a larger shot for good compression. Shotpeening's effects typically penetrates 4-8 thousands of an inch into the metal.
The Brian Crower rod's pin bushing is made of billet, hard silicon bronze. We used BC's stronger wide profile rods for our build. The wide profile rods require for the block to have some minor grinding for side clearance. Some people whine about doing this step so BC also makes a narrow profile rod which doesn't need grinding but is slightly less strong.
The 625+ rod gets its name from the ARP 625 plus rod bolts used. The bolts have an amazing tensile strength of 260,000 psi! This is up from the industry standard high end ARP 2000 bolt which has a strength of 220,000 psi. Since the rod bolts are normally the weakest part of any rod, the strength is critical. The ARP 625 plus rod bolts have up to 10 times the fatigue strength of other bolts. The 625 plus rod bolt is made from one of ARP's proprietary alloys that are super fatigue resistant and very resistant to corrosion and oxidation. In this close shot you can see the deeply pebbled surface of the aggressive shotpeening.
To complement our stroker crank we had a set of custom JE pistons made. We had the pistons made with a 9:1 compression ratio, up from the stock 8.5:1 and a compression height of 1.180″ to accommodate our increased stroke.
JE forged pistons are made of tough 2618 low silicon aluminum alloy. They are CNC machined to tight tolerances. In the case of our pistons, JE's latest FSR blank profiles were used. On this stroker dish top piston, the net shape of the forging is very close to what we want to run so no undercrown milling was needed to lighten the piston.