Tsuchinoko
EG6
- Joined
- Feb 19, 2008
- Messages
- 466
I hope this can help some of you that are building an engine.
I was searching on the web and I really can't remember were I found this very useful info.
Here is a chart of Honda B series bearing thickness by color. To calculate actual bearing clearance, use the following formula:
BC = IDBT â ODC â (2 x BT)
BC = bearing clearance
IDBT = inside diameter of bearing tunnel (housing bore)
ODC = outside diameter of crank journal
BT = bearing thickness
Although most people do not have inside micrometers, bearing micrometers or snap gauges, you can still use this chart when using plastigage to check bearing clearance. If you want to increase or decrease a bearing clearance, you can calculate how much of a color change is necessary by looking at the changes on the chart. Remember you can mix colors for even a more fine-tuning but it would not be wise to jump more than one color. In other words, do not mix a brown and yellow bearing together to equal a green clearance value. Just use the greens together. It is ok to mix a green with a yellow or a green with a brown. When doing your rebuild and replacing bearings with like colors, you still must check your results with plastigage to be sure. Donât assume anything. Also remember, when swapping to aftermarket rods, throw the color codes away as they will not work anymore. You need to start from scratch to obtain your desired clearance. On the other hand, you really cannot measure accurately to the nearest .0001â, so donât get carried away on that last one ten thousandth of an inch variance.
I was searching on the web and I really can't remember were I found this very useful info.
Here is a chart of Honda B series bearing thickness by color. To calculate actual bearing clearance, use the following formula:
BC = IDBT â ODC â (2 x BT)
BC = bearing clearance
IDBT = inside diameter of bearing tunnel (housing bore)
ODC = outside diameter of crank journal
BT = bearing thickness
Main Bearing thickness by color
Rod bearing thickness by color
Blue 2.013-2.010 mm 0.0793â- 0.0791â
Black 2.010-2.007 mm 0.0791â- 0.0790â
Brown 2.007-2.004 mm 0.0790â- 0.0789â
Green 2.004-2.001 mm 0.0789â- 0.0788â
Yellow 2.001-1.998 mm 0.0788â- 0.0787â
Pink 1.998-1.995 mm 0.0787â- 0.0785â
Red 1.995-1.992 mm 0.0785â- 0.0783â
Black 2.010-2.007 mm 0.0791â- 0.0790â
Brown 2.007-2.004 mm 0.0790â- 0.0789â
Green 2.004-2.001 mm 0.0789â- 0.0788â
Yellow 2.001-1.998 mm 0.0788â- 0.0787â
Pink 1.998-1.995 mm 0.0787â- 0.0785â
Red 1.995-1.992 mm 0.0785â- 0.0783â
Rod bearing thickness by color
Blue 1.510-1.507 mm 0.0594â- 0.0593â
Black 1.507-1.504 mm 0.0593â- 0.0592â
Brown 1.504-1.501 mm 0.0592â- 0.0591â
Green 1.501-1.498 mm 0.0591â- 0.0590â
Yellow 1.498-1.495 mm 0.0590â- 0.0589â
Pink 1.495-1.492 mm 0.0589â- 0.0587â
Red 1.492-1.489 mm 0.0587â- 0.0586â
Black 1.507-1.504 mm 0.0593â- 0.0592â
Brown 1.504-1.501 mm 0.0592â- 0.0591â
Green 1.501-1.498 mm 0.0591â- 0.0590â
Yellow 1.498-1.495 mm 0.0590â- 0.0589â
Pink 1.495-1.492 mm 0.0589â- 0.0587â
Red 1.492-1.489 mm 0.0587â- 0.0586â
Although most people do not have inside micrometers, bearing micrometers or snap gauges, you can still use this chart when using plastigage to check bearing clearance. If you want to increase or decrease a bearing clearance, you can calculate how much of a color change is necessary by looking at the changes on the chart. Remember you can mix colors for even a more fine-tuning but it would not be wise to jump more than one color. In other words, do not mix a brown and yellow bearing together to equal a green clearance value. Just use the greens together. It is ok to mix a green with a yellow or a green with a brown. When doing your rebuild and replacing bearings with like colors, you still must check your results with plastigage to be sure. Donât assume anything. Also remember, when swapping to aftermarket rods, throw the color codes away as they will not work anymore. You need to start from scratch to obtain your desired clearance. On the other hand, you really cannot measure accurately to the nearest .0001â, so donât get carried away on that last one ten thousandth of an inch variance.