Forged connecting rods Mitsubishi - 2.0L 16V - 4G63 7-bolt (156 mm rod length, 22 mm pin) for forged pistons

The Mitsubishi 4G63 engine (7-bolt)

The 4G63 is the 2.0-litre turbocharged four-cylinder that built Mitsubishi's motorsport legend. Part of the 4G6 family, this cast-iron block with an aluminium head (16 valves, DOHC) displaces 1,997 cm³ with an 85 mm bore and an 88 mm stroke. From 1996 Mitsubishi switched to a flywheel secured by 7 bolts (hence the "7-bolt" name), stiffer than the earlier 6-bolt design.

This 7-bolt version powers the Lancer Evolution IV to IX as well as the second-generation Eclipse and Talon. Famously near-indestructible, the 4G63T easily withstands power figures well beyond stock once the rotating assembly is upgraded. The rods shown here are long rods with a 156 mm centre distance (versus 150 mm stock), favoured on stroker builds or to optimise the rod/stroke ratio of an aggressive build.

Forged connecting rods

Machined from high-strength forged alloy steel, these rods replace the factory parts whose limit shows as soon as boost and rpm climb. Forging aligns the metal grain with the loads, delivering fatigue and bending resistance far beyond a mass-produced rod.

Each set ships with its ARP high-performance hardware (ARP 2000, L19 or CA625+ depending on the variant), factory-fitted. The range covers H and I profiles, in 4340 steel and, for the ZRP "IP" version, in 817M40T steel, to suit circuit builds as well as the most demanding big-turbo and rally setups.

Technical specifications of the 4G63 forged rods (7-bolt, 156 mm centres)

OEM reference: (set of 4 rods).

Torque and bolt stretch

Manufacturers recommend the stretch method rather than a torque figure: the actual bolt elongation is measured with a dedicated gauge, ensuring an even preload. The values above are indicative and must always be confirmed against the hardware maker's documentation.

Technical guide

Forged 4340 steel: what is it?

Rod profiles

	H profile (H / H-HD). The H-section body, with two solid flanges joined by a central web, is remarkably resistant to bending and compression: it is the profile to choose when torque is high and cylinder pressure heavy, typically a 4G63 built for drag racing or rallying. Slightly heavier than an I profile, it puts robustness first; the H-HD variant adds material in the most heavily loaded areas.
	I profile (I / I-HD). The I-section body concentrates material where the load passes and removes the rest: the rod is lighter, the inertia of the rotating assembly drops and the engine picks up revs more sharply. It is the choice of modern turbo engines and of builds looking for response; the I-HD version strengthens the big end and the body to take higher loads.

How to choose your rod hardware?

The rod bolt is one of the most heavily loaded parts of the engine. Every variant here uses ARP hardware in 3/8" diameter, a guarantee of reliability at high rpm. The grade choice depends on target power and budget.

	ARP 2000. Tensile strength around 220,000 psi (≈ 1,517 MPa). In 3/8", it secures about 200 hp per cylinder and rpm up to 8,500. The best performance/price ratio for the vast majority of builds.
	ARP L19. Very high strength grade (≈ 260,000 psi) for hard-driven engines: in 3/8", it allows about 250 hp per cylinder and rpm up to 10,000. Corrosion-sensitive, it requires oiled storage.
	ARP CA625+. Premium alloy steel designed for extreme environments (endurance, big-turbo). Superior strength and fatigue life, with no particular storage constraint.

Measuring bolt stretch

Discover the ARP stretch gauge

The brands offered

This page brings together two benchmark manufacturers, selected for their forging quality and motorsport reputation.

	Manley Performance. American manufacturer of competition engine parts since 1966. Its rods are machined from vacuum-degassed aerospace-grade 4340 steel, shot-peened to improve fatigue life and then inspected individually before shipping. The Turbo Tuff range, widely used on tuned 4G63 engines in the United States, is fitted with ARP 2000 or ARP L19 bolts depending on the target power.
	ZRP. Forged connecting rods designed by Alex Drakos in Athens, Greece, purely for competition use. Every part is forged from 4340 steel, machined and then weight-matched to ±1 g so the engine stays balanced at high rpm. On the 7-bolt 4G63, ZRP covers the H and I profiles with ARP 2000, ARP L19 or Custom Age 625+ bolts depending on the level of tune.

Glossary

1) Small end 2) Small-end diameter 3) Rod beam 4) Rod bolt 5) Big end 6) Rod nut / bolt 7) Rod cap 8) Big-end diameter 9) Center-to-center

Vehicle compatibility of the Mitsubishi 4G63 engine (7-bolt)

Why is it the most economical solution?

On a 4G63 that has thrown a rod, putting it back to standard is never an isolated job: the matching piston is destroyed, the crankshaft marked, sometimes the block needs boring. Added together, those original parts cost as much as a proper build, only to recover exactly the limits that caused the failure.

The same budget spent on forged 4340 rods and forged pistons changes the picture completely: the safety margin grows, the rotating assembly copes with pressures and revs the standard engine never saw, and power can be raised later without opening the bottom end again.

For comparable spending: more reliability, more durability, more potential.