Thread: crank bearings. ????????
09-03-2014, 12:56 PM #1
crank bearings. ????????
Some one please tell me why crank bearings the bottom ones dont have a oil chanel for oil to travel ..everytime I open and motorr the bottom bearings are shot ..I'm thinking about following the top one to the bottom same as top is this a good idea or a bad one ..explain please
09-03-2014, 01:30 PM #2
The reason for the oil groove on only half the bearing is to allow even oil distribution the moment it exits the oil hole. Once it hits the crank (and builds psi), the crank is then on a cushion of oil so the bottom bearing doesn't need the groove. Also, the other reason why the lower bearing is without groove is because those are under extreme stress from the combustion forces wanting to push crank away from block. If the lowers had grooves, there would be less surface area and much faster wear.
If you have unusually high lower bearing wear, it could be due to fatigued (worn out) main bolts/studs. Could also be caused from an out of spec crank. And if you ever overheated the motor, the block may need to be line-bored. There are MANY tell-tale signs to look for.
Post a picture of the bearings and I'll try to help.
09-03-2014, 02:56 PM #3
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