We all know there are two types of steel connecting rods on the market: the H-beam and I-Beam. Both are named for the resemblance of the connecting rod’s body to the associated capital letters. Each design has advantages over its counterpart and choosing which design to go with generally comes down to the intended application.
While Manley Performance makes forged 4340-steel connecting rods of both designs, they have now merged the two, for a new cross-sectional shape altogether. Dubbed the “Tri-Beam” connecting rod, the new design is part of the company’s Turbo Tuff line of rods, aimed at maximizing strength and minimizing weight.
Manley says that the Tri-Beam design will weigh the same or less than an identical I-Beam rod. Now, you might ask, “If it weighs the same, where’s the advantage?” By moving material to where it’s needed most, rather than just removing it from where it’s not needed, you get a stronger part at the same — or in some cases, less — weight.
This creates a unique shape with more “ribs” than you might be used to seeing on a connecting rod. Those, along with heavily radiused edges, where previously there were sharp edges and right angles, making for a design that is far less susceptible to fatigue.
The strengthening ribs extend all the way to the small end, enveloping the pin bore, to maximize strength while minimizing weight. Additionally, on the small end, the typical single wrist-pin oiling hole at 12 o’clock has been replaced by a pair of oil passages at 10 o’clock and 2 o’clock for much-improved wrist-pin lubrication.
Available in forged 4340 or 300M alloy steel for the ultimate strength, the Tri-Beam rods come standard with 3/8-inch ARP2000 cap screws, with an available upgrade to Custom Age 625-Plus bolts, for the ultimate in power-holding ability. Manley Performance’s Tri-Beam rod design goes a step beyond simply H-beam or I-beam rods, in order to withstand the harshest applications.