A Special Connection: Saenz Connecting Rods Offer Unique Materials

You may not have heard much about Saenz Performance in the past unless you were building specialty, one-off engines. Previously, its top-notch connecting rods only saw the inside of extremely high-performance engines or unique applications requiring custom manufacturing for production.

Believe it or not, Saenz’ connecting rods might be more common than you think. Saenz connecting rods have quietly done their work inside of some more well-known engines — such as various Cosworth powerplants. Only recently have Saenz Rods been branded and offered in the aftermarket as “off-the-shelf” components. We used their rods in the 427 cubic-inch LS we built in the latest series of Horsepower Wars’ LS Vs. Coyote 2. That engine made nearly 1,800 horsepower, and the rotating assembly was ready for more.

Saenz is a family-owned business, now in its third generation, headquartered in Miami, Florida. Ignacio Saenz runs the show, and he plays a huge role in the research and design that goes into its top-notch products. The company originated in the 1960s by his grandfather in Argentina, building gear sets, transmissions, and custom connecting rods.

Saenz Performance is a family business, currently in its third generation of operation, with roots in both Miami, Florida and Argentina.

About 40 years ago, Ignacio’s father and uncle split the Saenz family company and thus Saenz Performance became its own entity, focusing on only connecting rods. Saenz’ rods are all designed here in the United States. In many cases, the materials are sourced from the U.S. However, the production of all of Saenz’ products still happens in its facility in Argentina.

The idea of offering off-the-shelf connecting rods is fairly recent. It wasn’t until 2017 that Ignacio put some of their focus toward the average consumer and engine builder. The goal was to offer a truly affordable way to have quality rods available to the aftermarket.

“Many of the off-the-shelf rods on the market are just not of the quality they once were,” says Ignatio Saenz. “Their quality control practices are questionable and are almost all made in China. And it shows.” He went on to say some companies defy the stigma, and provide a remarkable product. However those options can be expensive.

We want to renew the market and take on the big names. – Ignacio Saenz

Let’s Talk Metallurgy

Saenz produces its connecting rods from three types of metal: 4340 forged steel, 300M vacuum-forged steel, and titanium. Without question, the difference in price from a set of off-the-shelf 4340 rods to custom titanium rods is vastly different. The bottom line though is Saenz wants to explore a larger piece of the market. In doing so, it expanded into offering a few different metals for various applications.

It’s so important to note the differences in application for each type of metal. For comparison and familiarity purposes, we know  aluminum rods are generally the lightest readily available option and are necessary in applications such as top fuel dragsters and even some bracket cars. Where aluminum rods are lacking, is their inability to be run for extended periods, without long periods of cool-down time. They shine in the drag racing world, because of the nature of its run-time. In a street/strip car or a cruiser, aluminum rods would fatigue with heat.

4340 forged steel rods are are truly the best bang for the buck. For your average hot rod or weekend drag strip warrior, this metal serves you very well. The 4340 alloy of steel is a strong nickel-chromium-molybdenum alloy, which is forged to further increase its strength. The tradeoff for affordable strength is weight. There is surely a threshold for horsepower and engine RPM where 4340 steel begins to fatigue. However for naturally aspirated engines and ones with modest power-adders, 4340 performs exceptionally well.

While these might look like I-beam rods at first glance, these Performance-series rods are actually Saenz proprietary three-beam design, which combines the benefits of both I- and H-Beam designs.

The next grade of metal available through Saenz is 300M vacuum forged steel. You might recognize this alloy as being used in premium axle shafts. Basically a modified 4340 steel, 300M has a slightly different chemical makeup, and is cast in a vacuum before forging. The differences offer both increased strength and malleability. Generally, 300M steel is a great upgrade to applications that would otherwise use a 4340 rod, as well as some applications that would traditionally use aluminum rods.

300M saves between 11- and 15-percent in weight versus 4340 while being drastically stronger. This metal tends to be more elastic than other steel forgings as well. 300M is a great metal choice for engines with big shots of nitrous or pushing quadruple-digit horsepower numbers. The long and short of this metal (versus 4340 and aluminum) is its additional strength characteristics over 4340 and the longevity over aluminum to drive your car home after driving the wheels off of it.

Saenz performs all of its own machining, allowing it to hold incredibly tight tolerances. Their forgings are made from a variety of US and South American steel, all with industrial certifications ensuring its purity.

In 2012, Jeremy Lookofsky set a milestone record at Englishtown, in his tube-chassis Honda, being the first all-motor four-cylinder car to break into the eights. He used a custom set of 300M Saenz rods, which were the only rods in existence in that material at the time. Since then, 300M rods have become increasingly popular in that next level of performance, where aluminum rods used to reign, unopposed.

Titanium falls in a league of its own, in that it is outrageously expensive in comparison to steel, and is typically only used in purely racing applications. Titanium rods are 40-percent lighter than 4340 steel versions. Because there is less metal needed to provide the appropriate level of strength, a titanium rod can be made even lighter than an aluminum rod of similar strength in certain situations.

A large advantage titanium carries over aluminum is the fact that titanium doesn’t need the extended cool-down period between runs. The metal is exponentially stronger than 4340 or 300M, but does have reduced elasticity. This is why it’s not a recommended metal for street applications.

Titanium rods aren’t just pretty. With it’s high strength ratio, titanium connecting rods can be made lighter than an equally strong aluminum rod, without the temperature drawbacks of aluminum. Their downside, of course, is the significant cost increase over aluminum.

Expanding Lines

Saenz’ S-series rods recently entered the market as its budget line of off-the-shelf connecting rods for the aftermarket. These are offered in an H-beam style, forged from a true 4340 steel from South America. The metal receives industrial certification and the final product goes through very strict quality control in the U.S., the same process as its custom products.

The real motivation for the Saenz team to offer this line is to provide what it considers to be a far superior product, to compete with the offshore-produced products coming from larger companies. “We want to renew the market and take on the big names,” says Saenz.

The next tier up from the S-series is Saenz’ Performance-series. These rods utilize its “three-beam design” which incorporates the best characteristics of H-beam and I-beam construction. Ultimately this makes the final product notably stronger. Performance-series rods are forged out of either 4340 or 300M, per customer choice. All of the metals used in Performance-series connecting rods come from the United States and carry the appropriate industrial certifications.

Extra time and energy is devoted to the final fit and finish of each Performance-series rod to ensure extreme precision. Without question, these come at a higher price than the S-series rods. However they stand in somewhat of a league of their own in the aftermarket.

Regardless of whether you choose 4340 or 300M steel, both options start life as an extremely strong forging (left). In the Performance-series rods, the "three-beam" design (right) combines H- and I-beam designs for an exceptionally strong connecting rod.

Last but certainly not least, are Saenz custom rods, which are truly limitless. Saenz still generates a majority of its business through the production of completely custom rods. Engine builders can to collaborate with the team at Saenz to create the correct connecting rod for their respective applications.

Titanium is an option in the custom-made rod lineup, along with 4340 and 300M steels. While Saenz offers a worksheet for rough-blueprinting a custom rod on their website, without question the best way to plan out a set of custom rods is to give the team a phone call. There are a multitude of details to be worked out concisely with the professionals, and that is best done on the phone.

For the LS vs. Coyote 2 supercharged build, Saenz and LME decided on a set of 300M connecting rod for the project. With their capability rated at upwards of 300 horsepower per rod, that capacity was proven as the engine made 1,784 horsepower and the rods held like a champ.

Saenz Rods are becoming increasingly popular in the sport compact world — predominantly in Honda and Mitsubishi engines. However they have a variety of other Japanese applications already engineered as well. Saenz’ 300M rods in particular are paving the way for a lot of records and wins, in arenas that are notoriously harsh on engine components.

The next big milestone in Saenz’ production is getting into the domestic markets with it’s off-the-shelf products for LS, big-block Chevy, and small-block Chevy connecting rods, with the other “Big Three” staples following right behind.

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About the author

Jake Longolucco

Jake’s itch for hot rods and musclecars stems back to when he first learned to walk. He built his 1967 Chevelle at the age of 14, which he still pounds the pavement in today. Jake is a graduate of Roger Williams University, and has a career as a firefighter in southern Rhode Island. His free time is spent wrenching on, and drag racing, GM musclecars. Jake believes all hot rods should have a third pedal. His aspirations include: winning a Wally and driving one of his old cars cross-country.
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