Tri-metal crankshaft main bearings King Subaru EJ205 EJ207 EJ255 EJ257

The Subaru EJ205, EJ207, EJ255 and EJ257 engines

The Subaru flat-four EJ205, EJ207, EJ255, EJ257 and EJ25 turbo engines (Impreza, Forester, Legacy, Exiga and WRX, full list below) share the same main bearing dimensions. King lists the MB5382XPG and MB5382XPGC bearing sets for this application: one set, in two versions, covers these engines.

The crankshaft of these engines runs on five main bearings. Each journal turns between two half shells, one seated in the block and the other in the main bearing cap: they carry the crankshaft. The KING RACING tri-metal set shown here replaces them on built engines.

Tri-metal main bearings

A tri-metal bearing stacks three layers: a steel back, a copper-lead intermediate layer with high load capacity and an anti-friction running surface that protects the journal. The complete set contains 10 half shells, five pairs for five main bearings.

An aluminium bi-metal takes around 8,000 psi, a performance tri-metal up to 12,000 psi, 50% more. Hence better resistance and better durability on turbocharged, supercharged and high-revving engines.

Technical specifications

Technical guide

The King main bearings shown here are trimetal bearings, designed for engine building and racing. Compared with an original bearing, they handle far higher loads: they cope with increased power, high rpm or the addition of a turbo or supercharger, where a standard bearing quickly reaches its limit.

The brand

King Engine Bearings, an Israeli manufacturer of high-performance engine bearings since the 1960s, offers with its pMax Black tri-metal alloy bearings designed for heavy loads, with a pMaxKote coating (XPGC version).

Construction and advantages

Criterion	King Racing
Cross-section
Type	High-performance trimetal bearing
Country of manufacture	Israel
Construction	Trimetal: steel back, copper layer, soft surface
Alloy	pMax Black (hardened copper-lead)
Protective coating	pMaxKote (XPGC version): polymer coating on the surface that limits wear when lubrication drops (start-ups, thin oil film).
Available sizes	Standard, StandardX, +0.026 mm, +0.25 mm

Vehicle compatibility

This main bearing set fits the following vehicles, according to the engine code: