Can somebody help me figure out why my main bearings are measuring out of specification? Both my used OEM and new King bearings are measuring DOUBLE the oil clearance specified in a 2017 Toyota 86 service manual.
2017 BRZ FA20D, 44k miles, performance rebuild.
Main bearings journal OD, specified: 67.985-68.003mm
Main bearing journal OD, measured: 67.986, 67.990, 67.990, 67.990, 67.989
Main bearing ID, not specified.
Main bearing ID, measured, used OEM bearings: 68.030, 68.046, 68.038, 68.038, 68.033
Main bearing ID, measured, new King bearings: 68.033, 68.046, 68.046, 68.051, 68.033
Oil clearance, specified: 0.013-0.031mm
Oil clearance, calculated, used OEM bearings: 0.044, 0.056, 0.048, 0.048, 0.044
Oil clearance, calculated, new King bearings: 0.047, 0.056, 0.056, 0.061, 0.044
-Ambient temp and block is 20.8C
-Block halves torques together per manual.
-I’m measuring the crank main journal OD directly with my micrometers after checking micrometer with the included gauge pin.
-I’m measuring the bearing ID by checking micrometers with a gage pin, setting the micrometer to 68.000mm, then zeroing my bore gauge to the smallest value I can get between the micrometer, then measuring the smallest value inside the bearing. My bore gage is inch so my math is 68.000mm+(measurement*25.4).
- Oil clearance = bearing ID - journal OD
Help. [emoji17]
