Manley Rod Bearing Set – Subaru EJ20 / EJ25 | 30070

Confirm bearing size (standard or oversized) against your crankshaft rod journal measurements before ordering. Rod bearings must be matched to the journal diameter — ordering the wrong size will result in incorrect oil clearance.

Confirm this set fits your specific EJ rod big-end bore diameter before ordering — EJ20 and EJ25 variants can differ depending on the connecting rod used (OEM vs aftermarket).

Manley 30070 rod bearing set for Subaru EJ20 and EJ25 horizontally-opposed 4-cylinder engines. Performance-spec rod bearings designed for use with Manley connecting rods in WRX, STI, and high-performance EJ builds. Full set of 4 rod bearing pairs included. 2 lbs. Ships fast across Canada and the US.

EJ Rod Bearing Failure — Why This Matters

Rod bearing failure is one of the most well-documented failure modes on the EJ20 and EJ25 engine family — particularly the EJ20 STI (Phase II with AVCS) and high-boost EJ25 WRX applications. Contributing factors include insufficient factory oil clearance on some production runs, the boxer engine’s tendency toward oil starvation at the rod journals under sustained lateral G-loading (track use, hard cornering), and elevated oil temperatures in modified or sustained high-RPM applications. Spun rod bearings on the EJ are engine-ending failures — the crankshaft journal and connecting rod big-end bore are both typically damaged beyond use. Preventative replacement during any EJ rebuild with performance-spec bearings at correct oil clearances is standard practice in the Subaru performance community.

Manley Performance Rod Bearings

Manley’s 30070 rod bearing set is spec’d for use with Manley EJ connecting rods. Manley rod bearings are selected and validated for consistent dimensions, controlled oil clearance, and durability under the high-RPM, high-load conditions of a built EJ. These bearings are the correct pairing for Manley connecting rods in a performance EJ build — using Manley rods with generic or OEM-spec bearings may result in incorrect clearances if the rod big-end bore is not standard OEM dimension.

Bearing Size — Measure First

Rod bearings are available in standard and oversized configurations to compensate for crankshaft journal wear. Before ordering, measure your crankshaft rod journal diameters with a micrometer and compare against the OEM specification — journals that have been turned undersize require oversized bearings to restore correct oil clearance. Installing standard bearings on an undersize journal results in excessive oil clearance and accelerated bearing wear. Confirm the 30070 size against your journal measurements before ordering.

EJ20 / EJ25 Application

The EJ20 (2.0L) and EJ25 (2.5L) share compatible rod bearing dimensions across many variants, which allows a single bearing set to cover both displacements. This set is designed for use with Manley connecting rods — if your build uses OEM rods or a different aftermarket rod manufacturer, verify the big-end bore dimension matches Manley’s rod specification before ordering this bearing set.

Measure crankshaft rod journals before ordering — confirm standard vs. oversized requirement. Match bearing set to the connecting rod big-end bore dimension. Plastigage oil clearances during assembly — target clearance for a performance EJ build is typically 0.0020–0.0025" (0.051–0.064mm); confirm with your engine builder. Replace rod bolts at every rebuild. Professional engine assembly required.

Specifications

• Brand: Manley Performance
• Part Number: 30070
• Type: Rod bearing set
• Quantity: 4 rod bearing pairs (full engine set)
• Application: Subaru EJ20 / EJ25 — with Manley connecting rods
• Weight: 2 lbs