ACL Subaru/Scion FA20 Standard Size High Performance Rod Bearing Set - 4B8310H-STD

The ACL Race Series High Performance Rod Bearing Set (Part # 4B8310H-STD) is a standard-size connecting rod bearing set engineered specifically for the Subaru/Scion FA20 engine family — the flat-four powerplant found in the BRZ, GR86, FR-S, and Toyota 86. Whether you're rebuilding a high-mileage engine, prepping for a performance build, or replacing worn bearings before they become a costly problem, ACL's Race Series is a go-to choice among enthusiasts and professional engine builders worldwide. Manufactured in Japan to exacting tolerances, this set brings genuine motorsport pedigree to your FA20 engine build.

Key Features & Benefits

• Motorsport-Proven Engineering: ACL Race Series bearings are recognized throughout the motorsports world, with a track record spanning sport compact drift racing, IHRA, NHRA, Bonneville, and NASCAR competition — giving you confidence that these bearings can handle demanding performance use cases beyond everyday street driving.
• Increased Eccentricity Design: ACL Race Series bearings feature increased eccentricity to improve shape adaptation, helping compensate for bore distortion that occurs at high-speed operation. This translates to better oil film retention and more consistent bearing-to-journal contact under stress.
• Precision Manufacturing to Exacting Tolerances: Each bearing is manufactured to tight dimensional tolerances, supporting consistent oil clearances critical for both naturally aspirated and modified FA20 engine builds.
• Unique Combination of Design, Metallurgy & Engineering: The Race Series' blend of materials and design provides endurance and capability in conditions where standard OEM bearings may fall short — ideal for builders pushing the FA20 with a tune, forced induction, or track use.
• Standard Size (STD): Designed for use with a standard (un-machined) crankshaft, making this the correct choice for most engine rebuilds using an unmachined or new crank.
• Made in Japan: These bearings are produced in Japan, consistent with ACL's manufacturing heritage and quality standards.
• Full Set Included: The set covers all four connecting rods in the FA20 four-cylinder engine (8 bearing halves total), so you have everything needed for a complete rod bearing replacement in one purchase.

Specifications

• Part Number: 4B8310H-STD
• SKU: ACL4B8310H-STD
• UPC: 9315726441398
• Size: Standard (STD)
• Application Engine: Subaru/Scion FA20
• Number in Pack: 8 bearing halves (full set of 4 rod journals)
• Country of Manufacture: Japan
• Brand: ACL Race Series

Fitment

The ACL 4B8310H-STD rod bearing set is designed for the FA20 engine and fits the following confirmed vehicles:

• 2013–2016 Scion FR-S (Base)
• 2022–2024 Subaru BRZ (Limited, Premium)
• 2017–2020 Toyota 86 (Base, GT, Hakone Edition, Special Edition, TRD Special Edition)
• 2022–2024 Toyota GR86 (Base, Premium)

Additional FA20-powered Subaru WRX and BRZ applications (2015–2021 WRX, 2013–2020 BRZ) are noted by other ACL retailers as compatible with this part number. If you are unsure whether this bearing set fits your specific build or if your crankshaft has been machined and requires an undersized bearing, contact our fitment team before ordering — standard size is only correct for unmachined crank journals.

Note: This is a standard-size bearing. If your crankshaft has been ground undersize, you will need the appropriate undersized bearing set instead.

What's in the Box

• 8 ACL Race Series rod bearing halves (complete set for all 4 connecting rods in the FA20 engine)

Why Buy from ThreePiece.us

• Free Shipping: Every order ships free — no minimum required.
• Affirm Financing: Spread your purchase over time with Affirm financing available at checkout, making it easy to build right the first time without waiting.
• Expert Fitment Support: Our team has served 10,000+ customers and specializes in helping enthusiasts get the right parts. Not sure if this is the correct bearing size for your build? Call us at 813-535-5801 or email [email protected].
• 10+ Years of Experience: ThreePiece.us has been serving performance enthusiasts since 2014 with a focus on getting the fitment right.
• Special Order Availability: This product is made to order in Japan. Lead time is approximately 16–24 weeks for special order fulfillment, so plan ahead for your engine build timeline.

Frequently Asked Questions

Q: What vehicles does the ACL 4B8310H-STD rod bearing set fit?
A: This set is engineered for the FA20 engine and is confirmed to fit the 2013–2016 Scion FR-S, 2022–2024 Subaru BRZ (Limited and Premium), 2017–2020 Toyota 86 (all trims), and 2022–2024 Toyota GR86 (Base and Premium). Additional FA20-equipped Subaru models may also be compatible — contact us to confirm fitment for your specific year and trim.

Q: Is this a standard size or undersized bearing — how do I know which I need?
A: The 4B8310H-STD is a standard-size (STD) rod bearing set, intended for use with an unmachined crankshaft with journals at the factory specification diameter. If your crankshaft has been turned or ground undersize during machine work, you will need the corresponding undersized bearing set. When in doubt, measure your crank journals or consult your engine machinist before ordering.

Q: How long will it take to receive this item?
A: The ACL 4B8310H-STD is a special order product made to order in Japan. Please allow approximately 16–24 weeks for delivery. If you need this part sooner, contact our team at 813-535-5801 to check current availability before placing your order.

Q: Does this set include bearings for all four connecting rods?
A: Yes. The set includes 8 bearing halves, providing a complete rod bearing replacement for all four cylinders of the FA20 four-cylinder engine.