BC6118 – Mitsubishi/DSM 4G63 2nd Gen/7 Bolt – ProH2K Connecting Rods w/ARP2000 Fasteners -156mm

In the high-stakes realm of forced induction and extreme RPM, the connecting rod is the ultimate linchpin between piston motion and crankshaft rotation. For the legendary Mitsubishi and DSM 4G63 engine—specifically the 2nd Generation 7-bolt variant—compromise in this critical component is not an option. The Brian Crower BC6118 ProH2K Connecting Rod set, featuring premium ARP2000 fasteners and a precise 156mm center-to-center length, is engineered to be that unbreakable link. Designed for builders targeting serious horsepower and relentless durability, these rods transform the 4G63’s bottom end from a potential failure point into a foundational pillar of power. This is not merely an upgrade; it is a calculated investment in engineering integrity for drag, track, or high-performance street applications where margin for error is zero.

Engineering the Core: ProH2K Technology & Material Science

The BC6118 rods are manufactured using Brian Crower’s proprietary ProH2K process, a hallmark of their performance line. This begins with a 4340 chromoly steel billet, vacuum-degassed to eliminate impurities that could initiate stress fractures. The “H2K” refers to a specialized heat-treating and shot-peening regimen that optimizes the molecular structure for both tensile strength and fatigue resistance. The result is a connecting rod with a superior strength-to-weight ratio, capable of handling the violent cylinder pressures of large turbochargers and high-boost applications without the unnecessary mass of an over-built “H-beam” design. The refined profile of the ProH2K rod reduces windage and oil drag within the crankcase, contributing to freer revving and increased horsepower output.

ARP2000 Fasteners: The Critical Interface

An elite rod is only as strong as its bolted connection. Brian Crower eliminates any weakness here by including industry-standard ARP2000 rod bolts. Manufactured from a custom 8740 chrome-moly steel alloy and heat-treated to 200,000 psi tensile strength, these fasteners provide a clamp load far exceeding OEM or standard aftermarket bolts. This is crucial for maintaining bearing crush and preventing cap walk under extreme loads, directly preventing catastrophic engine failure. The inclusion of these fasteners as standard equipment ensures the entire assembly is matched for performance, saving the builder from the cost and guesswork of sourcing compatible, high-grade bolts separately.

Definitive Advantages for the High-Performance 4G63

Choosing the BC6118 ProH2K rods translates into measurable and reliable benefits for your engine build. These advantages are rooted in material science, precision manufacturing, and proven track performance.

• Extreme Durability: The 4340 ProH2K steel construction and advanced heat-treating provide exceptional fatigue life, making them ideal for sustained high-RPM use and engines exceeding 800+ horsepower thresholds.
• Optimized Weight Reduction: Precision machining removes excess material without sacrificing strength, reducing reciprocating mass for improved throttle response and higher, safer engine speeds.
• Enhanced Oil Control: The rod’s design promotes efficient shedding of engine oil, reducing parasitic drag on the crankshaft and mitigating the risk of oil starvation—a common concern in high-g cornering or acceleration.
• Precision Fitment: Each rod is CNC-machined to exacting tolerances for big end diameter, center-to-center length (156mm), and wrist pin bore, ensuring perfect alignment and balanced cylinder pressures.
• Complete System Integrity: The inclusion of ARP2000 fasteners guarantees the clamping force necessary to keep the rod cap securely positioned under severe detonation or boost pressure.

Vehicle Fitment: Precision Application for 2nd Gen 7-Bolt Engines

The BC6118 is specifically engineered for a defined set of applications. Correct fitment is paramount for proper piston alignment, compression height, and overall engine geometry. This set is designed for the Mitsubishi/DSM 4G63 2nd Generation “7-bolt” engine. Key identifying features of this engine include a thrust bearing located on the #3 main bearing cap and a crank angle sensor (CAS) on the driver’s side of the cylinder head. It is critical to confirm your engine is a 7-bolt variant before purchase. Primary applications include:

Eclipse GS-T/GSX (1995-1999), Eagle Talon TSi AWD (1995-1998), Plymouth Laser RS-Turbo, and Galant VR-4 models equipped with the 7-bolt 4G63. These rods are also a direct fit for many JDM and Evolution I-III 4G63 long blocks that utilize the 7-bolt configuration. They are not compatible with 1st Generation 6-bolt 4G63 engines (1990-1994) or the 4G64 engine. Always verify engine model and casting numbers prior to installation. For a deeper technical understanding of 4G63 platform evolution and rod ratio implications, refer to this authoritative resource on building the 4G63 bottom end.

Technical Specifications & Installation Considerations

Below are the critical dimensions and specifications for the BC6118 ProH2K Connecting Rod set. These specs are vital for engine builders calculating compression, deck clearance, and ensuring compatibility with chosen pistons and crankshaft.

Installation & Final Build Notes

Professional installation is highly recommended. The rods must be paired with a crankshaft that has been micro-polished and measured for exact journal dimensions. The big end housings should be sized by a qualified machinist with the ARP2000 fasteners torqued to the manufacturer’s specified value—typically using a quality lubricant like ARP’s Ultra-Torque. This ensures perfect roundness and bearing clearance. Always perform a complete rotating assembly balance when installing these rods. The 156mm length maintains the factory stroke geometry, making them an excellent choice for both standard stroke and stroker crank applications when paired with the correct piston compression height. The BC6118 set represents the final word in 4G63 7-bolt rod technology, delivering the robust, precision foundation required to harness the full, brutal potential of this iconic engine platform.