Forged connecting rods Ford 3.5 EcoBoost & 3.7 Cyclone V6 for forged pistons

The Ford 3.5 EcoBoost and 3.7 Cyclone V6 engine

Ford's Cyclone V6 covers two engines built on the same 60° aluminium block: the naturally aspirated 3.7 Ti-VCT (3,726 cc) and the twin-turbo 3.5 EcoBoost (3,496 cc). Introduced in 2007 on the Duratec 35/37 base, this family powers a wide Ford and Lincoln range, from the F-150 pickup to the Mustang, with variable valve timing (Ti-VCT) and, on the EcoBoost, direct injection and two turbochargers.

On the 3.5 EcoBoost, forced induction raises factory output from 355 to 375 hp depending on the version (up to 450 hp on the Raptor and Ford GT), with strong torque from low rpm. As soon as boost pressure is increased, this potential heavily loads the rotating assembly: forged connecting rods then take over from the fracture-split factory rod, which is not designed to withstand high cylinder pressures.

Forged connecting rods

Machined from high-strength 4340 steel, these reinforced forged rods secure the bottom end of the 3.5 EcoBoost / 3.7 Cyclone V6 when torque and boost pressure rise. They replace the fracture-split factory rod, whose cost-driven design quickly reaches its limits in a performance build.

Available in I-Beam, I-3P and H-Beam profiles depending on the brand, they cover every discipline: drag, circuit, rally-raid, drift, hillclimb and sporty road use. Combined with 7/16" ARP bolts, they allow power targets well above stock while keeping lasting reliability.

Technical specifications of the Ford 3.5 EcoBoost / 3.7 Cyclone forged rods (23 mm pin)

Torque and bolt stretch

Manufacturers recommend the stretch-gauge method as the reference: the instructions supplied with the kit always take precedence. The torque figures below assume assembly with ARP lubricant.

OEM reference:

Technical guide

4340 forged steel: what is it?

Connecting rod profiles

	I profile (I-Beam, Manley). Its slimmer central section cuts reciprocating mass and frees up rpm while keeping good strength under boost.
	I-3P profile (Boostline). This three-pocket I-beam combines lightness and rigidity, ideal for modern turbo engines running high boost pressure.
	H profile (H-Beam, Manley). Its two massive flanks give maximum rigidity in compression: the reference profile for high-torque engines and drag builds.

A note on the oil hole: the rods shown here are solid-body (no oil hole), for maximum strength including beyond 600 hp. The rifle-drilled versions (with oil hole), recommended up to around 600 hp, are covered by a dedicated listing.

How to choose your rod bolts?

The rod bolts clamp the rod cap and absorb inertia loads at high rpm. Here they use the larger 7/16" diameter instead of the usual 3/8", increasing the clamping area and joint strength. Three ARP grades are offered depending on the build level:

	ARP 2000: reinforced alloy, tensile strength around 1,517 MPa (~220,000 psi). The best strength/price compromise for most boosted 3.5 EcoBoost and 3.7 builds.
	ARP 8740: heat-treated chromoly steel, strength around 1,380 MPa (~200,000 psi). Factory fitment on Manley H-Beam rods, suited to moderate high-torque builds.
	ARP Custom Age 625+: aerospace superalloy, strength around 1,793 MPa (~260,000 psi). Reserved for extreme builds and the highest sustained rpm.

Measuring bolt stretch

Buy the ARP stretch gauge →

The brands offered

	Manley Performance: a leading American manufacturer, H-Beam and I-Beam profiles in 4340 steel, renowned in drag and endurance for their strength.
	Boostline: patented three-pocket I-3P profile combining lightness and rigidity, designed for modern turbo engines.

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 Ford 3.5 EcoBoost and 3.7 Cyclone V6 engines

These forged rods fit the 3.5 EcoBoost (turbo) and 3.7 Ti-VCT (naturally aspirated) V6 of the Cyclone family. Main Ford and Lincoln applications:

Why it’s the most cost-effective solution?

Rebuilding a 3.5 EcoBoost or 3.7 V6 after a bent rod costs far more than a set of forged rods fitted preventively. The fracture-split factory rod is not designed for high cylinder pressures: in a build it becomes the engine's weak link.

A set of six 4340 forged rods protects the crankshaft, pistons and block from the very first power increases. It is a one-time investment that avoids a costly engine failure and downtime.

Supplied with their 7/16" ARP bolts, these rods fit during a standard rebuild and offer a lasting safety margin, on the road, on track or in competition.