Inline Four now offers OEM Honda crankshaft main bearings for your engine building needs. We do so many engine builds, that we have many of these bearings in stock. All of the B-series engines, as well as K-series engines, share the same main bearing design. All B-series and K-series crankshaft main bearings have an "upper" and a "lower" bearing. The upper and lower are different from each other. The upper has a groove or channel down the center section of the bearing, whereas the lower bearing does not. Be sure to make sure you are ordering your bearings correctly and in the right quantities of upper and lower. There are a total of 5 upper and 5 lower main bearings on a crankshaft, for a total of 10 individual main bearings.
Below is a chart of all the colors offered by Honda and their respective thicknesses. The top of the chart is the thickest bearing and the bottom is the thinnest bearing. You can "half-shell" and use two different colors to achieve the desired clearance. However, we suggest not to jump up or down more than one color.
Main Bearing thickness by color
Blue 2.013-2.010 mm 0.0793”- 0.0791”
Black 2.010-2.007 mm 0.0791”- 0.0790”
Brown 2.007-2.004 mm 0.0790”- 0.0789”
Green 2.004-2.001 mm 0.0789”- 0.0788”
Yellow 2.001-1.998 mm 0.0788”- 0.0787”
Pink 1.998-1.995 mm 0.0787”- 0.0785”
Red 1.995-1.992 mm 0.0785”- 0.0783”
Main bearings are sold as "single" pieces. Adjust your quantity accordingly in the shopping cart.