Connecting Rods: Selection

Each rod falls into one of four tolerance ranges (from 0 to + 0.024 mm (0 to + 0.0009 in), in 0.006 mm (0.0002 in) increments) depending on the size of its big end bore. It's then stamped with a number (1, 2, 3, or 4) indicating the range.

You may find any combination of 1, 2, 3, or 4 in any engine.

Normal Bore Size: 48.0 mm (1.89 in)

NOTE:

Reference numbers are for the big end bore size and do NOT indicate the position of the rod in the engine.
Inspect each connecting rod for cracks and heat damage.

Fig 1: Identifying Connecting Rod Position
Courtesy of AMERICAN HONDA MOTOR CO., INC.