Block Bore Code Location

Letters or bars have been stamped on the end of the engine block as a code for the size of each of the four main journal bores.

Use them, and the numbers or bars stamped on the crankshaft (codes for main 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: Main Bearing Selection Identifying Block Bore Code Location

Courtesy of AMERICAN HONDA MOTOR CO., INC.

Fig 2: Main Bearing Selection Reference Chart

Courtesy of AMERICAN HONDA MOTOR CO., INC.

Main Journal Code Locations (Numbers or Bars) 

Fig 3: Identifying Main Journal Code Locations

Courtesy of AMERICAN HONDA MOTOR CO., INC.