ACL Race Series Bearings

The best bearings for an engine rebuild are performance bearings sized to your crankshaft journals. ACL Race Series rod and main bearings are a go-to for performance rebuilds, covering Subaru FA20 and EJ engines, Honda K-series, the Mazda Miata, and Nissan VQ35DE applications. Bearings are inexpensive parts that protect very expensive ones, so they are never the place to cut corners in a build.

Rod and main bearings sit between the crankshaft journals and the rods and main caps, carrying the engine’s full rotating load on a thin film of oil. When that film breaks down — from high RPM, high cylinder pressure, or worn journals — bearings fail, and they can take the crank with them. ACL’s Race Series is the company’s performance line, engineered for higher loads than standard replacement bearings. Included are rod bearing sets for the 2015-2021 WRX and 2013-2021 BRZ/FRS/86 FA20, 1990-2005 Mazda Miata, Honda H22A4 and K20A2/K24A, and 2003-2006 Nissan 350Z VQ35DE, plus main sets for 2002-2014 WRX and 2004-2021 STI with the #5 thrust bearing position. Bearings come in standard and undersize options — undersize sets are for reground crankshafts, so the correct size is determined by measuring your journals, not by guessing.

ACL, the Australian bearing maker, built its performance reputation on the Race Series line of rod, main, and thrust bearings. The breadth of this collection shows the brand’s strength: dedicated Race Series sets for Subaru FA20 and EJ engines, Honda H and K series, the Mazda Miata, and Nissan’s VQ35DE. ACL bearings are a standard machine-shop recommendation because the standard and undersize options cover both fresh and reground crankshafts.

King Bearings is another performance-bearing specialist carried at JDMuscle. King’s performance lines are engineered for high-load and racing applications — the natural brand to compare against ACL when spec’ing a rebuild.

Clevite is a longtime engine-bearing manufacturer whose performance bearings have been used in street and race engines for decades. Clevite’s tri-metal designs are well regarded in V8 and import performance circles alike.

Browse the full bearings collection for related options, and pair bearings with fresh rods and rings during a rebuild. Two common starting points: the ACL Rod Bearing Set for 2015-2021 WRX and 2013-2021 BRZ/FRS/86 FA20 and the ACL Rod Bearing Set for 2003-2006 Nissan 350Z VQ35DE. For broader WRX build ideas, see our top 3 aftermarket parts for the Subaru WRX series.

What is the difference between ACL Race Series and standard replacement bearings?

Race Series is ACL’s performance line, designed to handle higher loads than standard replacement bearings. For a stock rebuild, standard bearings are fine; for boosted, high-RPM, or track use, Race Series is the safer choice.

How do I know whether I need standard or undersize bearings?

Measure your crankshaft journals — undersize bearings suit cranks reground to a smaller diameter. Your machine shop will confirm the correct size after measuring; never guess.

Should bearings be replaced during every rebuild?

Yes. Bearings are wear items and are inexpensive relative to a crankshaft or a full rebuild. Fresh rod and main bearings are standard practice in any engine that is apart.

Do I need to check oil clearances?

Yes — verify bearing clearance during assembly with plastigage or micrometers against your build’s specs. Correct clearance keeps the oil film intact under load.