Fortifying your big-block Chevy for boosted power levels just got a little easier with Callies Performance Products’ Compstar Xtreme connecting rods, as the company aimed to support enthusiasts and racers looking for a capable connecting rod, but also in need of managing their budget.
“We felt there was a need for a rod that will cover a vast majority of the applications out there without getting into the higher end, expensive rods,” said Callies’ Brook Piper. “The Compstar Xtreme is good for wild street cars, drag racing vehicles, mild power-adder—anything up to 1,800 horsepower.”
Piper told us that the Compstar Xtreme product line is an old product line that they have re-designed with the latest technology and thinking, while doing so to create a line that kept the costs down.
That said, the Compstar Xtreme connecting rods are manufactured from 4340 chromoly steel overseas, and then Callies Performance Products handles all of the finish work here in the United States.
“They are made overseas to our spec, and then we inspect, bolt, and hone them here in the USA, just as with every other Compstar product we offer,” Piper explains.
As Compstar Xtreme was a former product line, Callies Performance Products gave it’s Compstar Xtreme big-block Chevy connecting rods a number of updates to make them a competitive option in the market.
“The first thing we did in the re-design was incorporate the same rod bolt that we use in our Ultra rods, which is the H-11 material,” Piper tells us. “Upgraded bolts and clearance for stroker rotating assemblies are standard with Compstar connecting rods. What we learned in the high-end applications we transferred over to this rod. These are Compstars on steroids.”
The overall design of the Compstar Xtreme connecting rods is essentially an H-beam design, but Callies made subtle changes, such as adding weight in key areas to improve their strength and durability, while at the same time being weight-conscious and reducing weight in areas by removing material. The groove down the center of the rods is just one area where efforts to reduce the weight, and thus rotating mass, of the connecting rods were made.
The company also listened to engine builders and their concerns and wants. One thing Callies heard from engine builders was how connecting rods often went out of round, whether it was during initial assembly or reassembly after a rebuild. To address this, Callies employs a lengthy stress relief process and multiple re-torque processes to ensure its Compstar rods’ big-bore ends remain round no matter how any times they are assembled and re-assembled. Furthermore, the company also spends considerable time ensuring the rods are properly prepared. Callies chamfers and hones the pin bushings for proper high-performance oil clearance, chamfers the parting line edges to resist any scraping that might occur during insertion of the bearing shells, and also de-burs the bearing locating tab slots for trouble-free installation.
On the Compstar Xtreme’s web page, Callies notes that forged side relief-style pistons that move the pin boss inwards are becoming increasingly popular. Knowing this, the engineers at Callies designed the Compstar Xtreme rods with a .990-inch pin end width to allow them to be used with all currently available FSR or forged side relief-style pistons.
Callies also engineered the Compstar Xtreme connecting rods in ways that reduce the amount of time a machine shop may need to modify the rods or block. The area above the rod bolts was designed to increase cam clearance, as was the rod bolt placement, and this in turn decreases the amount of clearance needed at the bottom of the cylinder bores. Compstar Xtreme connecting rods are also equipped with ARP 2000 or L19 fasteners for optimum strength at the clamping areas.
The Compstar Xtreme connecting rods for big-block Chevy engines is just the first product in the lineup, as Callies will be offering the model for small-block Chevy, Ford’s Godzilla 7.3, Ford Powerstroke, LS and eventually Cummins diesel applications.