ACL Race Main Bearings for WRX EJ20 EJ205 STi EJ25 EJ255 Thrust #5 Position

Description

ACL TRI-METAL RACE SERIES Main Bearing Set
Part #
5M8309H-STD
(For Thrust in #5 Position)
The unique combination of design, metallurgy and engineering come together to deliver what drivers expect from high performance  Tri-metal engine bearings.
Designed to withstand higher RPM conditions, ACL Race Series Engine Bearings are available for many of the popular 4, 6 & 8 cylinder applications and feature:
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High strength overlay plate
with reduced thickness for improved fatigue properties
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Hardened steel backs
on all rod bearings to improve the support of the bearing lining and assist with bearing retention in the housing.
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Increased crush
for improved bearing retention
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Elimination of flash plating
on the back of the bearings to improve heat transfer through the bearing sand to maximize the grip between the bearings and its housing.
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Increased eccentricity
to compensate for bore distortion at high rpm and to assist in the formation of hydrodynamic oil films.
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3/4 grooved Main Bearings
to optimize bearing load carrying surface area and oil flow to the con-rod bearings.
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Tight consistent wall tolerances
to help you maintain consistent clearances.
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Enlarged ID chamfers
on bearing edges where required to accommodate large fillet radius on performance crankshafts.