Connecting Rods

How much extra boost and rpm can your stock connecting rods really handle? This category brings together connecting rods as single rods and complete sets for engine projects where power is increased significantly or where the engine is built from the ground up.

What connecting rods do in the engine

The connecting rod links the piston to the crankshaft and converts combustion pressure into rotation. At higher boost and rpm, both compressive and tensile loads increase, and a stock rod can become the weak link. For engine projects with more power, we stock connecting rods from e.g. Brian Crower, Carrillo, BoostLine, Hot Rods and Skunk2 Racing.

How to choose connecting rods

Start with the engine code. The rods are made for specific engines, e.g. Honda K24, Mitsubishi 4B11T or Nissan VR38, and the same engine can come in several variants. Then compare these points:

• Length: the centre-to-centre distance between the two eyes, e.g. 152 mm or 6.125 inches, must match the crankshaft, pistons and deck height.
• Profile: H-beam and I-beam distribute the material differently; which one suits you depends on power target, rpm and weight.
• Bolts: the bolts are often one of the most highly stressed points, and the product names show different bolt materials, e.g. ARP2000 and ARP Custom Age 625+.
• Single or set: some items are sold as one rod, others as a complete set – check the product description.

Installation requires measuring bearing clearances and tightening according to the manufacturer's instructions, typically by measuring bolt stretch. If the wrist pin needs a new bushing, you'll find them under wrist pin bushings.

Frequently asked questions

Should I choose H-beam or I-beam connecting rods?

It depends on the engine, power target and rpm. Both profiles are used in high-load engines, and design and material matter more than the profile alone. Follow the manufacturer's recommendation for your specific project.

Can connecting rod bolts be reused?

It depends on the manufacturer's instructions. Bolts tightened to a specific stretch must be measured at every installation, and if the stretch is outside tolerance, the bolt must be replaced. Always use the specified lubricant when tightening.

Does the engine need balancing when I change connecting rods?

Often yes, because new rods typically weigh differently than the stock ones. It depends on the weight difference and the engine, so let an engine builder assess whether the crankshaft, pistons and rods should be balanced together.