 Rebuild advice, Crank discoloration |
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| tscrihfield |
 Jun 2 2011, 09:00 PM
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#1
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Drive Fast and Take Chances  Group: Members Posts: 643 Joined: 8-September 10 From: Amelia Ohio Member No.: 12,156 Region Association: None 
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So I have a concern. During the inspection of a crank I recently obtained I found discoloration (much like gun blue) on the area outside of the middle main journal. I'm not as versatile in air-cooled engines and im not sure if this is normal??? All of the journals mic'd fine and well within spec. This is not a good sign when dealing with most engines I know, but I am wondering if this is normal. Would this be a replace scenario?
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| tscrihfield |
Jun 2 2011, 09:02 PM
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#2
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Drive Fast and Take Chances Group: Members Posts: 643 Joined: 8-September 10 From: Amelia Ohio Member No.: 12,156 Region Association: None
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To clarify it is in the thrust bearing area, not on the actual journal itself.
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| r_towle |
Jun 2 2011, 09:05 PM
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#3
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Custom Member Group: Members Posts: 24,574 Joined: 9-January 03 From: Taxachusetts Member No.: 124 Region Association: North East States
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Not sure where you are talking about.
Is this a used crank? You may want to get it polished. Rich |
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| Jake Raby |
Jun 2 2011, 09:05 PM
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#4
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Engine Surgeon Group: Members Posts: 9,394 Joined: 31-August 03 From: Lost Member No.: 1,095 Region Association: South East States |
Totally normal if its what I believe that it is.. I have seen NOS cranks for TIV engines have this discoloration.
post some pics. |
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| tscrihfield |
Jun 3 2011, 08:02 AM
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#5
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Drive Fast and Take Chances Group: Members Posts: 643 Joined: 8-September 10 From: Amelia Ohio Member No.: 12,156 Region Association: None
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QUOTE(Jake Raby @ Jun 2 2011, 11:05 PM)  Totally normal if its what I believe that it is.. I have seen NOS cranks for TIV engines have this discoloration. post some pics. Will post pictures when I get home. This is a stock 2 liter crank and it is used, but the journals are in terrific shape. |
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| tscrihfield |
Jun 3 2011, 03:32 PM
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#6
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Drive Fast and Take Chances Group: Members Posts: 643 Joined: 8-September 10 From: Amelia Ohio Member No.: 12,156 Region Association: None
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QUOTE(tscrihfield @ Jun 3 2011, 10:02 AM) QUOTE(Jake Raby @ Jun 2 2011, 11:05 PM) Totally normal if its what I believe that it is.. I have seen NOS cranks for TIV engines have this discoloration. post some pics. Will post pictures when I get home. This is a stock 2 liter crank and it is used, but the journals are in terrific shape. (IMG:http://www.914world.com/bbs2/uploads_offsite/i163.photobucket.com-12156-1307136732.1.jpg) This is the area of discoloration... Let me know what you think. I will have it polished anyway but this is my only area of concern. |
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| Don M |
Jun 4 2011, 07:18 AM
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#7
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Newbie Group: Members Posts: 41 Joined: 22-August 09 From: California Member No.: 10,707 Region Association: None |
appears to be trace discoloration from factory induction hardening process, as long as size, finish and run-out are acceptable not a problem
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| tscrihfield |
Jun 4 2011, 08:39 AM
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#8
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Drive Fast and Take Chances Group: Members Posts: 643 Joined: 8-September 10 From: Amelia Ohio Member No.: 12,156 Region Association: None
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QUOTE(Don M @ Jun 4 2011, 09:18 AM) appears to be trace discoloration from factory induction hardening process, as long as size, finish and run-out are acceptable not a problem Thanks! Glad to hear that! I thought it might have been from heat treating but wasn't so sure! |
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