Tri-metal crankshaft main bearings Nissan SR20DE SR20DET

The Nissan SR20DE and SR20DET four-cylinder engines

The SR20DE and SR20DET are the Nissan 2.0 litre four-cylinder engines with twin overhead camshafts and 16 valves, the latter turbocharged. They power the Nissan 180SX, 200SX, Silvia, Primera, Sunny, Serena and Bluebird, among others. ACL and King list a main bearing set for 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 ACL Race Series and KING RACING tri-metal sets shown here replace 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. The upper and lower half shells are different: each goes in its own position.

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 ACL and 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 two brands

	ACL Bearing Company, an Australian manufacturer of high-performance engine bearings since 1949, offers with its Race Series precise tri-metal bearings, available in many sizes and proven on built engines worldwide.
	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 (XPC version).

Construction and advantages

Criterion	ACL Race Series	King Racing
Cross-section
Type	High-performance trimetal bearing	High-performance trimetal bearing
Country of manufacture	Australia	Israel
Construction	Trimetal: steel back, copper layer, soft surface	Trimetal: steel back, copper layer, soft surface
Alloy	Race Series (copper-lead)	pMax Black (hardened copper-lead)
Protective coating	Calico CT-1 (HC and HXC versions): thin dry-film lubricant that reduces friction and wear. No coating on the H and HX versions.	pMaxKote (XPC version): polymer coating on the surface that limits wear when lubrication drops (start-ups, thin oil film). The XP version has no coating.
Available sizes	Standard to +0.50 mm (+ increased clearance HX) ; Calico: standard, HXC and +0.25 mm	Standard to +0.50 mm (+ increased clearance STDX) ; XPC: standard, STDX and +0.25 mm

Vehicle compatibility

This main bearing set fits the Nissan SR20DE and SR20DET four-cylinder engines of the following vehicles: