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Trimetal connecting rod bearings Nissan L Series

New product

Set of 8 trimetal connecting rod half-bearings for Nissan L Series, Z Series and FJ20 engines.

  • Brand and treatment: ACL Race
  • Engines: L Series (1,296 to 1,770 cc), Z Series, FJ20E, FJ20-ET
  • Available sizes: standard to +0.25 mm, increased-clearance version (HX)

More details

94,20 € tax incl.

-5%

99,16 € tax incl.

  • The Nissan L Series engines

    The Nissan L Series engines (1967 to 1986) are petrol four-cylinder engines of 1,296, 1,428, 1,595 and 1,770 cc. ACL lists the same connecting rod bearing set, the 4B1171H, for these engines, for the Z Series engines of 1,595 and 1,770 cc and for the FJ20E and FJ20-ET: same crankpin diameter, a single set covers these engines.

    From the factory, this engine is fitted with standard production connecting rod bearings, sized for the loads of the original engine: as soon as power, engine speed or boost pressure increase, they reach their limits.

    Trimetal connecting rod bearings

    A trimetal 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 8 half shells, four pairs for a four-cylinder engine.

    The original bearing relies on an aluminium alloy over a steel back, intended for low to medium loads, whereas trimetal is designed for high, sustained loads: an aluminium bi-metal takes around 8,000 psi, a performance trimetal up to 12,000 psi, 50% more. Hence better resistance and better durability on turbocharged, supercharged and high-revving engines.

    Technical specifications

    Fitment dimensions common to all references
    ACL bearings
    Crankpin Ø 49.962 / 49.975 mm
    Housing bore Ø 53.005 / 53.013 mm
    Width 22.1 mm
    ReferenceBrand and treatmentSizeWall thickness (mm)
    4B1171H-STDACL Race - UntreatedStandard1.504
    4B1171HX-STDACL Race - UntreatedStd, increased clearance (HX)1.491
    4B1171H-.025ACL Race - Untreated+0.0251.5165
    4B1171H-.25ACL Race - Untreated+0.251.629

    Running clearance

    The running clearance is the gap between the bearing and the journal where the oil film flows.

    In operation, the crankshaft journal does not rub against the bearing: it rides on this oil film, which carries the load. Clearance sets the thickness of this film: too tight, oil flows poorly, temperature rises and the risk of seizure increases; too loose, oil escapes, the film loses load-carrying capacity and oil pressure drops. The right clearance is the balance between adequate lubrication and a well-maintained oil film.

    Size / gradeWhen to choose itACL Race Series
    Standard (STD)Standard journal, not reground0.053 to 0.063 mm
    Increased clearance (HX)Wider clearance: high oil flow, high rpm0.078 to 0.088 mm
    +0.025 mmPolished journal0.053 to 0.063 mm
    +0.25 mmJournal reground to 0.25 mm0.053 to 0.063 mm

    Checking on assembly: lay a calibrated strip (Plastigauge) on the journal, torque the rod cap to spec, then compare the crushed strip against the gauge to read the clearance.

    Plastigauge

    Order the Plastigauge →

    Technical guide

    The ACL rod 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

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

    Vehicle compatibility

    This connecting rod bearing set fits the following Nissan engines:

    BrandModel (chassis)Engine codePowerYears
    NissanL Series (1,296 cc)L Series1967–1986
    NissanL Series (1,428 cc)L Series1967–1986
    NissanL Series (1,595 cc)L Series1967–1986
    NissanL Series (1,770 cc)L Series1967–1986
    NissanZ Series (1,595 cc)Z Series
    NissanZ Series (1,770 cc)Z Series
    NissanFJ20EFJ20E
    NissanFJ20-ETFJ20-ET