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Crankshaft Clearances

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JGRANTAMX View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote JGRANTAMX Quote  Post ReplyReply Direct Link To This Post Posted: Apr/07/2021 at 5:30am
 I did find a small variation last night that might explain why I have .004" end play when there is .008" clearance between the crank and thrust bearing, one of the bearing cap 1/2" thru holes is .005" off center in the cap at the mating surface the issue could be a stack up of tolerances, I didn't think much about it at first the 1/2" holes measure .520" and should clear the studs without issue. With .004" end play I can hear the crank make a light clunk sound when moved from back to front I am going to leave it as is thanks for the replies.

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Post Options Post Options   Thanks (0) Thanks(0)   Quote Steve_P Quote  Post ReplyReply Direct Link To This Post Posted: Apr/07/2021 at 1:48pm
If I'm understand correctly.....  If you are using studs, and threading them all the way in, you can have the issue you describe because you've eliminated all of the angular thread clearance between the male stud and female thread in the block.  When you do this, the stud is following the thread in the block like a pressed dowel pin.  And maybe the female thread is off half a degree.  So now the stud is.  And project that out 3" (whatever it is) and you can end up being off .010"+ easily.

If you use a bolt, it will register on the top of the cap and not try and move it.  If you loosen the stud half a turn in the block, where it will move front to rear a little, it should allow you to set the cap like you want it.
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JGRANTAMX View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote JGRANTAMX Quote  Post ReplyReply Direct Link To This Post Posted: Apr/07/2021 at 8:57pm
 Sounds like it could work I will give that a try and post.

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Class Guy View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Class Guy Quote  Post ReplyReply Direct Link To This Post Posted: Apr/08/2021 at 6:51am
Studs are supposed to be installed only finger tight.
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JGRANTAMX View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote JGRANTAMX Quote  Post ReplyReply Direct Link To This Post Posted: Apr/08/2021 at 8:52am
The studs are finger tight the instructions does say not to torque them down they don't need to be bottomed out.

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JGRANTAMX View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote JGRANTAMX Quote  Post ReplyReply Direct Link To This Post Posted: Apr/09/2021 at 4:25am
 I tried turning the bearing cap studs a half turn last night to see if that would change the crank end play there is no difference still .004".

J
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