An example of Carrillo Industries' finished high-performance connecting rods.
Tapping the electric steelmaking furnace at Timken's Faircrest plant in Canton, OH.
For 15 years The Timken Co. has been the sole supplier of "Parapremium" steel used by Carrillo Industries to produce high-performance connecting rods. Timken (www.timken.com) produces Parapremium steel at its Faircrest plant in Canton, OH, an operation anchored by a 160-ton electric arc furnace. Applications for the steel, in addition to connecting rods, include crankshafts, gears, bearings, pinions, down-hole oil tools, and aircraft engine parts. Timken supplies the steel to Trinity Forge, Mansfield, TX, which in turn produces the con-rod forgings for Carrillo Industries Inc.
Choosing the right grade of steel can be the difference between success and failure, reliability or lack of it, for a demanding application like a connecting rod. Facing continuing demand for increased power density, Carrillo asked Timken to recommend a steel alloy that would allow for increased performance.
Carrillo Industries Inc. has been manufacturing and supplying the automotive aftermarket with connecting rods for more than 40 years. Its success is proof, and a further justification, of the care that the San Clemente, CA, company takes to investigate alternatives that improve the con rods for its customers.
Parapremium steel is tested and certified to meet the standards of AMS-2304 — a specification that requires the cleanliness levels of vacuum-arc-remelted steels for air-melted products. It's a steel that consistently meets the critical strength, ductility, chemical, and quality requirements set by Carrillo for optimal performance, and also supplies improved power density.
"High quality, consistency, service, and support are the cornerstones of a successful business and the standards that have guided Carrillo to success," according to Jack Sparks, vice president. "In order to sustain our position in the global motor-sports industry, it is imperative that our suppliers maintain the same standards of excellence, which is why Timken has been a supplier for more than 15 years."
Timken worked closely with Trinity Forge, a closed-die operation to meet those demands.
"We've been forging bar from Timken for more than 25 years and have come to expect consistent, superior quality," says Trinity Forge v.p. Jim Parsley. "In the years we've worked with Timken, their record for quality has become a model for excellence in steel suppliers. That track record continues with this grade for Carrillo's connecting rods."
Together, Timken and Trinity Forge assessed how to improve power density for this application. The critical elements required were strength, ductility, and consistent quality and chemical properties that would provide optimum performance in the application. For this, Timken recommended its Parapremium steel, a base-alloy grade that is extremely clean, offers improved processing variables and ultra low sulfur, and is calcium-treated.
"In order to meet the changing needs of our customers, we continue to introduce more customized solutions," explains Troy Powell, Timken's Steel Group alloy steel account manager. "The properties of this Parapremium steel offered Carrillo a stronger material for its applications."
Since demonstrating the performance and reliability of the connecting rods, Carrillo has enjoyed positive response from a variety of customers, and has gained recognition as the "officially licensed" connecting-rod supplier for NASCAR.
In turn, Trinity Forge and Timken have been established as the sole forger and steel supplier to Carrillo Industries.
In 1963, Fred Carrillo identified a need for dependable, high-quality connecting rods for the world of high-performance auto racing. Many parts of the internal combustion engine are prone to failure, but one of the most susceptible is the connecting rod, which transfers energy from the engine's combustion chambers to the crankshaft, and ultimately to the final drive mechanisms. A failed connecting rod results in a lost race and the destruction of a very expensive engine.
Since the inception of its connecting-rod business, Carrillo Industries has concentrated its effort on precision and quality construction. "Our design goal for every rod we make is to maximize strength and durability while minimizing weight," the company claims.
Fred Carrillo's experience with engines is based on several decades of active competition with motorcycles, dragsters, and open-wheel race cars. Fred combined his aerospace background with his years of competitive racing to design and manufacture a durable and long-lasting connecting rod that would stand up to the most severe conditions that develop during competition. Fatigue is the major cause of connecting rod failure. Carrillo's solution is to use proprietary steel, "manufactured and forged to our own custom specifications. Our connecting rods are fully machined to guarantee the removal of all surface imperfections in the forging. After heat treatment, each connecting rod is 100% Magnaflux inspected and hardness checked, then machined to final size. Each set of rods is balanced and then shot-peened to achieve the ultimate in strength and fatigue properties," it boasts.
Carrillo Industries manufactures various connecting-rod configurations. Online (www.carrilloind.com) it provides an extensive catalog of its more popular con-rod designs. "Our manufacturing procedures ... are fundamentally simple in nature: we blend the accuracy and repeatability of computer assisted machinery with the craftsmanship and attention to detail offered by qualified and concerned employees."
Trinity Forge specializes in forging complex shapes in various sizes, to strict customer specifications. Operating since 1955, the company produces closed-die forgings for industries ranging from transportation to oil field drilling and mining. It forges carbon, alloy, and stainless steel, as well as nickel-and copper-based alloys and titanium.
Its 80,000-ft2 manufacturing operation houses forging cells capable of producing parts weighing from a few ounces to over 100 lb. Over the past decade, it reports, it has invested to modernize its forging and machining technology. "We use high-speed horizontal machining centers and CNC lathes for tooling production," it states. "This reduces tooling rework time as well as time-to-market for new products."