Connecting Rod Bearing Selection

Each connecting rod falls into one of four tolerance ranges (from 0 to 0.024 mm (0.00095 in), in 0.006 mm (0.00024 in) increments) depending on the size of its big end bore.

It is then stamped with a number or bar (1, 2, 3, or 4/I, II, III, or IIII) indicating the range. You may find any combination of 1, 2, 3, or 4/I, II, III, or IIII in any engine.

Big End Bore Size 

60.0 mm (2.362 in) 

Inspect the connecting rod for cracks and heat damage.

Big End Bore Code Locations 

Numbers or bars have been stamped on the side of each connecting rod as a code for the size of the big end. Use them, and the letters or bars stamped on the crank (codes for rod journal size), to choose the correct bearings. If the codes are indecipherable because of an accumulation of dirt and dust, do not scrub them with a wire brush or scraper. Clean them only with solvent or detergent.

Fig 1: Identifying Big End Bore Code Locations

Courtesy of AMERICAN HONDA MOTOR CO., INC.

Fig 2: Bearing Color Code Chart

Courtesy of AMERICAN HONDA MOTOR CO., INC.

Connecting Rod Journal Code Locations (Letters or Bars) 

Fig 3: Identifying Connecting Rod Journal Code Locations (Letters And Bars)

Courtesy of AMERICAN HONDA MOTOR CO., INC.