measuring main bearing crush
#1182512
02/20/12 02:44 AM
02/20/12 02:44 AM
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Joined: Jul 2006
Posts: 4,179
California
mickm
OP
master
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OP
master
Joined: Jul 2006
Posts: 4,179
California
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i'm putting together a hemi, and a friend who is a builder was asking about the bearing crush, so i took each cap, put in the bearing, and brought the cap close to seating with both bolts, and then tightened only one side to 60 ft lbs. i then measured the distance between the cap and the block on the other side, and got the following measurements, 1-5.
.004 .006 .005 .005 .006
this seems like a lot, but i was wondering how accurate this is with the cross bolt of the inner mains, if that would get in the way of the cap being able to come close down and show the actual crush.
does this work on a hemi block? is this the correct way to check this?
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Re: measuring main bearing crush
[Re: mickm]
#1182513
02/20/12 03:20 AM
02/20/12 03:20 AM
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Joined: Aug 2003
Posts: 43,223
Bend,OR USA
Cab_Burge
I Win
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I Win
Joined: Aug 2003
Posts: 43,223
Bend,OR USA
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Quote:
i'm putting together a hemi, and a friend who is a builder was asking about the bearing crush, so i took each cap, put in the bearing, and brought the cap close to seating with both bolts, and then tightened only one side to 60 ft lbs. i then measured the distance between the cap and the block on the other side, and got the following measurements, 1-5.
.004 .006 .005 .005 .006
this seems like a lot, but i was wondering how accurate this is with the cross bolt of the inner mains, if that would get in the way of the cap being able to come close down and show the actual crush.
does this work on a hemi block? is this the correct way to check this?
No 
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
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Re: measuring main bearing crush
[Re: Cab_Burge]
#1182514
02/20/12 03:48 AM
02/20/12 03:48 AM
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Joined: Aug 2003
Posts: 43,223
Bend,OR USA
Cab_Burge
I Win
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I Win
Joined: Aug 2003
Posts: 43,223
Bend,OR USA
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There are specs. on the main bearing bore sizes, usually they allow .001 or less varience, to get how much crush the main caps are affecting your bearing you can measure the inside bore of your block with the main caps tighten down without the bearings in them and then measure the thickness of each bearing, add the two thickness together and then install them into the mains with the caps tighten down, measure the I.D. and see how much clearance you have. Subtract the bearing thickness from I.D. you meausred and the difference is the amount the bearings cruched in the block, I think  It should be less than .0010 I think thats the proper way  I worry about the total clearnances as long as the bearings do not move around in the bores easily, they should snap in and stay there  That is the crush as I see it
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
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Re: measuring main bearing crush
[Re: Cab_Burge]
#1182516
02/20/12 11:33 AM
02/20/12 11:33 AM
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Joined: Oct 2003
Posts: 21,345
Marysville, O-H-I-O
70Cuda383
Too Many Posts
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Too Many Posts
Joined: Oct 2003
Posts: 21,345
Marysville, O-H-I-O
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Quote:
There are specs. on the main bearing bore sizes, usually they allow .001 or less varience, to get how much crush the main caps are affecting your bearing you can measure the inside bore of your block with the main caps tighten down without the bearings in them and then measure the thickness of each bearing, add the two thickness together and then install them into the mains with the caps tighten down, measure the I.D. and see how much clearance you have. Subtract the bearing thickness from I.D. you meausred and the difference is the amount the bearings cruched in the block, I think It should be less than .0010 I think thats the proper wayI worry about the total clearnances as long as the bearings do not move around in the bores easily, they should snap in and stay there That is the crush as I see it
that's all I've done too. if they "click" into place and stay there, then I torque the caps and measure them, then the journal, to know my bearing clearances.
**Photobucket sucks**
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