ARP 251-5002 ARP2000 12pt Main Bolt Kit for Ford 1.6L EcoBoost 4-Cylinder Engine

Vehicle Fitment

• Universal - Fits any vehicle equipped with the Ford 1.6L EcoBoost 4-Cylinder engine, including the 2014-2019 Ford Fiesta ST (1.6L EcoBoost). Fitment is engine-specific, not vehicle-specific. Verify your engine code before ordering.

Fitment Notes

• This kit is designed for the Ford 1.6L EcoBoost 4-cylinder engine only. It is not compatible with any other Ford EcoBoost displacement - for the 2.3L EcoBoost, see ARP 251-5001 (bolt) or 151-5407 (stud); for the 1.6L EcoBoost main stud kit, see ARP 251-5402.
• ARP2000 main bolts replace the factory OEM Torque-to-Yield (TTY) main bolts. OEM TTY bolts are one-time-use fasteners that permanently stretch during torquing - they must not be reused. ARP2000 bolts are reusable and do not yield during torquing.
• This is a main bearing cap bolt kit - not a head stud or rod bolt kit. For 1.6L EcoBoost head studs, see ARP 251-4302.
• Installation requires ARP Ultra-Torque assembly lubricant (sold separately or included - verify at point of purchase) for accurate torque readings. Do not use engine oil or other lubricants as a substitute, as this will result in incorrect clamp load.

Features

• Manufactured from ARP2000 proprietary alloy steel - heat treated to a nominal 220,000 psi tensile strength, delivering approximately 200% the fatigue life of conventional 8740 chromoly steel fasteners and up to 40% greater tensile strength than OEM TTY main bolts.
• 12-point head design allows the use of standard 12-point sockets for installation in tight-clearance main bearing cap areas, providing positive drive engagement and reducing the risk of rounding during torquing.
• Precision centerless ground and thread-rolled to MIL-S-8879 specifications after heat treatment - rolling threads after heat treat produces threads significantly stronger than cut threads and eliminates subsurface stress risers.
• Eliminates main bearing cap walk and fretting - a critical concern in high-power turbocharged applications where combustion pressures repeatedly load the main caps with greater force than OEM fasteners were designed to handle.
• Protects main bearing bore threads in the engine block by distributing clamp load evenly through precision-ground parallel washers, preventing thread damage caused by the uncontrolled stretch of TTY OEM hardware.
• Black oxide finish provides corrosion resistance and a clean appearance inside the engine build.
• Reusable - unlike OEM TTY bolts, ARP2000 main bolts can be removed and reinstalled multiple times without loss of clamping integrity, provided stretch specifications are monitored.
• Includes hardened parallel-ground washers for uniform load distribution and accurate torque readings.
• Designed, manufactured, and tested in the USA by ARP (Automotive Racing Products) in Ventura, California.

Specifications

• Part Number: 251-5002
• Application: Ford 1.6L EcoBoost 4-Cylinder Engine - Main Bearing Cap Bolts
• Material: ARP2000 Alloy Steel
• Tensile Strength: 220,000 psi (nominal)
• Head Style: 12-Point
• Finish: Black Oxide
• Thread Form: Precision J-Form, rolled after heat treatment
• Kit Includes: Main bearing cap bolts and hardened parallel-ground washers

Included Components

• Complete set of ARP2000 12-point main bearing cap bolts (quantity per Ford 1.6L EcoBoost engine specification)
• Hardened parallel-ground washers

Product Description

The ARP 251-5002 is an ARP2000 12-point main bearing cap bolt kit engineered for the Ford 1.6L EcoBoost 4-cylinder engine - the turbocharged four-pot found in performance applications including the Ford Fiesta ST. It is the direct main bolt replacement in the ARP 251-series Ford EcoBoost fastener lineup, sitting alongside the companion 251-5402 main stud kit and the 251-4302 head stud kit for the same engine platform.

The factory main bolts in the Ford 1.6L EcoBoost are Torque-to-Yield (TTY) fasteners - a design that stretches past the elastic limit of the material during torquing to create a controlled clamp load. While TTY fasteners are acceptable for stock power levels, they are single-use items that cannot be reused once removed, and their reduced residual strength makes them unsuitable for high-boost, high-cylinder-pressure performance builds where the main bearing caps are subjected to significantly elevated loads. The ARP 251-5002 replaces the entire set of OEM TTY bolts with ARP2000 alloy hardware that delivers a nominal 220,000 psi tensile strength - approximately 40% more than the OEM fasteners - while remaining reusable across multiple engine assemblies.

ARP2000 material shares similar machinability with 8740 chromoly steel but is heat-treated to a higher level, enabling the greater strength rating. All bolts are precision centerless ground and thread-rolled after heat treatment to MIL-S-8879 specifications - a process that produces threads with significantly higher fatigue resistance than cut-thread fasteners, eliminating subsurface stress concentrations that can initiate cracking under cyclic loading. The 12-point head design allows use in tight main cap clearance zones with standard tooling. Hardened parallel-ground washers are included to distribute clamp load evenly across the bearing cap and protect block threads from the localized stress that can cause thread pull-out or deformation during high-torque assembly. Confirmed by the ARP official website (arp-bolts.com) and the 2026 ARP product catalog as the correct main bolt kit for the Ford 1.6L EcoBoost 4-cylinder.