 Bearing clearance, 2056 build #2 |
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| Chad911sc |
 Nov 21 2025, 01:23 PM
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#1
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Member  Group: Members Posts: 218 Joined: 24-September 24 From: Florida Member No.: 28,374 Region Association: South East States  |
So I got my crank back from a different machine shop this time, and they turned it down .010 on the mains to clean up my out of roundness. I rotated it several rotations on an V-block and had no deviation. My new oversized bearing came in yesterday, and I’m checking clearances now. I plastigauged the middle bearing and I have what looks to be .0018 of clearance. Is this acceptable? Here is the pics to double check me.
My rods were right at .001, so I’m good there. Attached thumbnail(s)  
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| rfinegan |
Nov 21 2025, 01:56 PM
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#2
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Senior Member Group: Members Posts: 1,137 Joined: 8-February 13 From: NC Member No.: 15,499 Region Association: MidAtlantic Region 
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.001 feels a little tight to me on the rods. Careful
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| mepstein |
Nov 21 2025, 02:00 PM
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#3
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914-6 GT in waiting Group: Members Posts: 20,247 Joined: 19-September 09 From: Landenberg, PA/Wilmington, DE Member No.: 10,825 Region Association: MidAtlantic Region
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I would have the machine shop do the measurements. They have measuring tools that are much better than plastigauge.
You really want to measure at every bearing. Just measuring one and hoping the others are the same can get you in trouble. |
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| Chad911sc |
Nov 21 2025, 02:50 PM
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#4
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Member Group: Members Posts: 218 Joined: 24-September 24 From: Florida Member No.: 28,374 Region Association: South East States |
@rfinegan
I didn’t have the rod journals turned, they were right on spec. The rods were bought new from LN engineering, and they prepped and sized them before shipping. The engine ran for around 3 hours the first time, and the bearings upon disassembly were fine. They were definitely reusable, but I bought new ones anyway. @mepstein The machine shop did mic each journal and they were all right on spec. I then rechecked them when I got home and obtained the same results. From what I’ve read, the clearance should be .002 on the middle bearing because it takes the load of 2 rods. Mine looks like it’s a hair tighter, so I was wanting to know if that is acceptable, or do I need to polish t a bit and try to get it right at .002 |
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