Bearing questions...
Guest
Posts: n/a
To the guys who've put together SOHC and DOHC bottom ends, I have a couple questions... How can you tell what color bearings to use (main and rod) when you dont have any bearings to judge the tolerances with? Basicly I have a block, crank, rods and pistons. Im trying to rebuild this SOHC bottom end and make it last a little while. I dont have any useable bearings from the stock crank, this crank is out of another Y8 motor. the rods are from a motor that spun a bearing.
According to the helms manual you can use the bearing sizing chart provided which will provide you with bearing colors to use for the crank/block/rod combo you have.
If I were to ever mix/match a setup, I would use the helms as a refference point, then I would use plastiguage to ensure the tolerances are proper.
If you really want to get involved with bearing sizing you could have a machine shop mic everything up for you
I have posted this before, but here it is again:
MAIN:
Letters are on the block, numbers are on the crank, put the two together to get color code
ROD:
Letters are on the crank, numbers are on the rods, same process as above
Blue .0594-.0593
Black .0593-.0592
Brown .0592-.0591
Green .0591-.0590
Yellow .0590-.0589
Pink .0589-.0587
Red .0587-.0586
BC = IDBT – ODC – (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
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”
Rod bearing thickness by color
Blue 1.510-1.507 mm 0.0594”- 0.0593”
Black 1.507-1.504 mm 0.0593”- 0.0592”
Brown 1.504-1.501 mm 0.0592”- 0.0591”
Green 1.501-1.498 mm 0.0591”- 0.0590”
Yellow 1.498-1.495 mm 0.0590”- 0.0589”
Pink 1.495-1.492 mm 0.0589”- 0.0587”
Red 1.492-1.489 mm 0.0587”- 0.0586”
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. Don’t 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 .0001” without machinist quality tools, so don’t get carried away on that last one ten thousandth of an inch variance.
If I were to ever mix/match a setup, I would use the helms as a refference point, then I would use plastiguage to ensure the tolerances are proper.
If you really want to get involved with bearing sizing you could have a machine shop mic everything up for you

I have posted this before, but here it is again:
MAIN:
Letters are on the block, numbers are on the crank, put the two together to get color code
ROD:
Letters are on the crank, numbers are on the rods, same process as above
Blue .0594-.0593
Black .0593-.0592
Brown .0592-.0591
Green .0591-.0590
Yellow .0590-.0589
Pink .0589-.0587
Red .0587-.0586
BC = IDBT – ODC – (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
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”
Rod bearing thickness by color
Blue 1.510-1.507 mm 0.0594”- 0.0593”
Black 1.507-1.504 mm 0.0593”- 0.0592”
Brown 1.504-1.501 mm 0.0592”- 0.0591”
Green 1.501-1.498 mm 0.0591”- 0.0590”
Yellow 1.498-1.495 mm 0.0590”- 0.0589”
Pink 1.495-1.492 mm 0.0589”- 0.0587”
Red 1.492-1.489 mm 0.0587”- 0.0586”
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. Don’t 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 .0001” without machinist quality tools, so don’t get carried away on that last one ten thousandth of an inch variance.
__________________

Authorized Dealer & Tuner for: Hondata, eCtune, Neptune, AEM, Crome, Precision Turbo, Omni Power, Walbro, Innovate & more. Dyno Tuning Services, Ecu Chipping, Chipped Ecus, Conversion Harnesses, Widebands, Fuel Injectors, Fuel Pumps, Map Sensors & more.
For more information visit http://www.Phearable.net or call 1-888-236-9831

Authorized Dealer & Tuner for: Hondata, eCtune, Neptune, AEM, Crome, Precision Turbo, Omni Power, Walbro, Innovate & more. Dyno Tuning Services, Ecu Chipping, Chipped Ecus, Conversion Harnesses, Widebands, Fuel Injectors, Fuel Pumps, Map Sensors & more.
For more information visit http://www.Phearable.net or call 1-888-236-9831
Last edited by mtber; Mar 7, 2005 at 01:56 PM.
Guest
Posts: n/a
Ok, I haven't put together bearings or rings on a Honda motor yet. And Im a little iffy about it. How many thrust washers go in there?
How do I know what letter/number combo = what color?
Once I get those bearings and plastiguage them what if it's out of tolerance? Do I just goto the next size bearing?
How do I know what letter/number combo = what color?
Once I get those bearings and plastiguage them what if it's out of tolerance? Do I just goto the next size bearing?
Originally Posted by Cronic
Ok, I haven't put together bearings or rings on a Honda motor yet. And Im a little iffy about it. How many thrust washers go in there?
How do I know what letter/number combo = what color?
Once I get those bearings and plastiguage them what if it's out of tolerance? Do I just goto the next size bearing?
How do I know what letter/number combo = what color?
Once I get those bearings and plastiguage them what if it's out of tolerance? Do I just goto the next size bearing?
__________________

Authorized Dealer & Tuner for: Hondata, eCtune, Neptune, AEM, Crome, Precision Turbo, Omni Power, Walbro, Innovate & more. Dyno Tuning Services, Ecu Chipping, Chipped Ecus, Conversion Harnesses, Widebands, Fuel Injectors, Fuel Pumps, Map Sensors & more.
For more information visit http://www.Phearable.net or call 1-888-236-9831

Authorized Dealer & Tuner for: Hondata, eCtune, Neptune, AEM, Crome, Precision Turbo, Omni Power, Walbro, Innovate & more. Dyno Tuning Services, Ecu Chipping, Chipped Ecus, Conversion Harnesses, Widebands, Fuel Injectors, Fuel Pumps, Map Sensors & more.
For more information visit http://www.Phearable.net or call 1-888-236-9831
Great info!!! That will sure help me putting this motor together
__________________

www.facebook.com/chris.storck1
Project WHIPLASH has begun!!!
RacingIntegration.com (813)935-6720
InductionPerformance.com
NS Racing (813)842-5517

www.facebook.com/chris.storck1
Project WHIPLASH has begun!!!
RacingIntegration.com (813)935-6720
InductionPerformance.com
NS Racing (813)842-5517


