A good feature of the eagle rods is that the rod is forged in two pieces with the cap forged separately. This allows the rod to have the metal’s grain flow in a circle around the big end bore. With this forging method there is less distortion of the rod’s big end under load and superior strength of the part, especially fatigue strength.
The rod’s have “H” profile beams. The “H” profile puts the rods stiffness axis in line with the bending stresses it sees under use, making the rod strong for its weight. At 100 grams per rod lighter than the stock H22 rods, this is pretty significant. In fact the Eagle H22 rods are 15 grams lighter than the shorter Eagle SR20 rods for additional savings!
If you look in the machined valley of the “H” you will notice a rib at the base of the valley, this rib increases the fatigue strength of the rod’s beam. The oiling holes for the piston pin are drilled upwards at an angle towards the pin. Putting two smaller holes at the bottom makes a much stronger part than your typical single bigger hole at the top of the pin bore.
|Our Eagle rods with the big ends narrowed, WPC Treated and ready to rock!|
The entire surface of the rod is machine finished. This ensures consistency in dimensions and weight. It also creates a smooth finish with no irregularities where a crack inducing stress riser can form. After machining, the rod is subjected to shotpeening. This is where the rod is bombarded by hard steel shot at high velocities. Shotpeening helps refine the grain over the surface of the rod, creating a finely grained compressed layer of steel where cracks have a hard time propagating. Shotpeening causes the fatigue strength of most steel parts to rise by over 100%.