RECONDITIONING RODS WITH A HIGH-PERFORMANCE BOLT UPGRADE
TEXT: Henry De Los Santos
PHOTO: Henry De Los Santos
When the time comes to tear apart your mill for a rebuild, regardless of whether it’s a daily driver or a performance powerplant, several decisions need to be made beforehand to help prioritize your build and budget. If it’s a basic rebuild and you’re planning to retain most of the hardware, such as the rods, then you’ll want to have them checked out and reconditioned by a competent machine shop.
If this is a project you would like to tackle yourself, then we’ll go ahead and tell you that it’ll require a sizable investment in specialized machinery. Rather than focusing on the equipment, we wanted to showcase the steps it takes to recondition a set of rods and help give you a better understanding of where your hard-earned greenbacks are going.
While you’re at it, and depending on your long-term plans for your mill, you may want to consider a rod bolt upgrade. If you didn’t already know it, rods of any given internal combustion engine are subjected to extremely volatile environments. Think of it this way: It’s the rod bolt that’s holding the rod cap in place and expected to accelerate on command, all the while forcing the rod to push and pull throughout the entire rpm band.
Again, any rod bolt upgrade should be contingent on the final designation of your mill. If there are any plans to tickle the throttle at various functions, then you’ll be wise to spend a little more up front for the added insurance. If your build is nothing more than a basic rebuild for a driver, then forgo the bolt upgrade and save the money for other expenses. However, if we can make one suggestion, never opt out of the reconditioning rod option from the machine shop. Sure, it may save you a Benjamin now, however if longevity is a factor then this is one place you don’t want to skimp out on. Follow along as Rocco Acerrio of A.R.E. Performance & Machine gives us an inside look at the rod reconditioning process.
01 These are 6.135-inch length rods out of a 454ci big-block. If you’re planning to upgrade the rod bolts, the factory pieces need to be removed with a press.
02 Whenever you’re upgrading the rod bolts, it’s important to press in the new piece from the beginning. If the new bolts are pressed in after the rod has been reconditioned, there’s a fairly good chance that the bores will end up out of round, requiring another machining session to correct it.
03 Our choice for the rod bolt upgrade included these ARP Wave-Loc High Performance bolts. The Wave-Loc bolts are designed to have its surface contact the rod and cap for optimum alignment and reduction of fluctuating stress; as a bonus, this adds strength to the rod.
04 To begin the machining process, the rod is placed into a grinder to remove 0.002 inch off the face of the rod and cap.
05 Next, both edges of the rod and cap are deburred.
06 Using the 10-ton press again, it took nearly 21/2 tons of force to press in the new ARP Wave-Loc bolts.
07 The rod is then placed into the rod vice, which holds the rod and cap square, and torque to 50 ft-lb with ARP Ultra-Torque assembly lube.
08 With the rod assembled, the honing machine’s gauge is set to the factory specifications. After the initial cap and rod grinding, the gauge showed that our rods were now 0.003-inch undersized from the factory spec.
09 Since the big-end bore is undersized from grinding it, the goal is to hone it until it’s round again and back to the standard size. The factory diameter ranges from 2.3247 to 2.3252, so the gauge is set to 0 on the low side and the final numbers need to be in the middle of the low and high side of the spec.
10 The rod is now honed, round, and to its correct size. The only thing left to do is to allow the rod to sit and cool and then come back to it in an hour to double check the dimensions. Once it’s cool, the rod may shrink a little bit; if it’s too small then the rod will be touched up again, and then it’s ready to go.
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