Think of the time when you decide to build or overhaul your next engine. You might not know that choosing the right connecting rod will be an important decision to make. Any time you intensify the output of your engine, the first element tested is the strength of your connecting rods.

They may not in themselves add to more of a power output. But they do create more stability for other upgrades used for the power increase. Thus, the connecting rod has to be strong enough to handle any upgrades to your engine. This article will give you an inside look into the importance of choosing the right connecting rod for your build.

connecting rod

Connecting rod for a sports car engine.

How Does a Connecting Rod Work?

Let’s take an internal combustion piston engine, such as in your automobile. The connecting rod joins the piston to the crankshaft. The connecting rod is a major link. It pushes and pulls the pistons converting the reciprocating motion to a rotating motion. This way the crankshaft can rotate through both halves of a complete revolution. The power created from the piston to the crankshaft is then transferred to the transmission.

There are a few types of materials and production methods used in manufacturing connecting rods. These are: cast steel, forged steel (aftermarket, fully machined, and stock), billet steel, aluminum, and titanium. Most commonly, aluminum and steel are used. They are most commonly produced through casting, powder metal, and forging. The rod itself is comprised of three parts: Pin end, shank end, and crank end. Parallel holes are bored into the upper and lower ends to allow bearings to fit.

Upgrading to a stronger connecting rod will let you more effectively handle an increase in power load on your engine. Most stock engines will incorporate a powder metal rod. This is because they are economical and give enough support to a vehicle used with normal driving power loads. If you are looking to add torque and horsepower to your engine, this type will not hold up to the increase in spins at higher RPMs. You will need to upgrade to an aftermarket part which can handle the increased power if you are looking to build a street performance or racing application.

General Specifications

  • Forged steel H, A, and X beam connecting rods made from proprietary high strength steel alloy area good upgrade choice.
  • Lighter rods are good for better acceleration. Heavier rods are better for higher horsepower.
  • Connecting rod upgrades come in every price range.
  • Applications up to 2.500 horsepower for racing builds are available.
  • Aluminum rods are good for top fuel and blown alcohol engines. The reason is that they slightly flex to absorb the combustion shock.
  • Rods come in various lengths with many popular lengths being between 5.700 and 6.385.
  • Shorter rods deliver improved low end torque and increased throttle response over a larger RPM range.
  • Longer rods supply more high RPM power within a tighter RPM range.

PROs and CONs of Connecting Rod Upgrades

PROs

  • More Power Capacity – Upgrading the connecting rod in your vehicle will give you the ability to upgrade other parts which will increase your torque and power.
  • Rebuilding Ability – On a stock engine the connecting rods, because they are usually powder metal, have a cracked end rod cap. When the bore gets out-of-round, you cannot simply grind and bore the end. You have to replace the whole rod. An upgrade will allow you to refinish the end and get more use out of it.
  • Variety – With such a wide variety of rod lengths, you can attempt to get yourself the perfect ratio for your build. There are upgrades for top-racing applications, drag racing, street performance, marine engines, restoration and high horsepower.

CONs

  • Weight increase – A better, sturdier rod usually means an increase in weight. If you are trying to go faster, that is something not wanted.
  • Price – As with pretty much any other aftermarket part, there is an increase in price.
  • Replacement Cost – More than likely you are upgrading to get more power and torque. With more power comes more wear and tear. All rods will fatigue after so many turns and will bend and crack. Depending on your application, you may in turn experience a need to replace your parts more often. Especially if you are going more towards running a funny car or drag racer.
  • Knowledge – Some people like a simple upgrade. Pick the one for your make and model, and install. There is a little more to upgrading your connecting rods. You have to consider the horsepower load it will be under, type of application, which types are best for your build, rod length and ratio. When certain things aren’t taken into consideration or if it is not installed correctly it can cause quite a bit of damage.

Examples of Connecting Rod Parts

R&R Racing Products

R&R Racing is a family owned business that has been a trusted name in the industry for over a decade. They manufacture aluminum connecting rods catering to the racing community. They also strive to stay up with technology. Furthermore, they are continuously improving upon their rods in order to stay ahead of the competition. And reviewers can see the difference.

They rave about R&R’s product quality saying it far surpasses expectations. Reviewers also really like the fast speed of the turnaround time of their orders.

Eagle

Eagle connecting rods utilizes a two-piece forging process that increases the life of their rods by minimizing fatigue. They also forge their rod caps separately to give their connecting rods superior strength. Eagle also uses a higher amount of nickel and chrome. These further minimize fatigue and increase strength without creating a brittle part.

Their rods give a weight savings of between 30 and 70 grams. Reviewers love their product because of all the added pluses from a larger stroke application to their extremely thorough testing process.

DPR Racing Inc

DPR is not a new name in the game. They have been in the business for over 60 years. And that invested time comes with a lot of knowledge. Their products have been breaking records and sweeping championships for years.

DPR has gained a strong following and built a powerful reputation for their first-class quality. Reviewers can’t say enough about their high quality and knowledge. Pair that with their friendly staff and you definitely have a winning brand.

connecting rod & piston

Powering Up

Your build is only as strong as its weakest link. Connecting rods are an integral part and can either make or break your ability to support an increase in torque and power. So, even though it in itself does not provide power output, it is important to upgrade it so it can help other upgrades do their part.

Have you had success in finding your perfect ratio? What material does your connecting rod have? Please share your thoughts and experiences below.

The images are from depositphotos.com.

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