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torque to yield by FieroJosh1993
Started on: 09-10-2013 11:06 PM
Replies: 3 (106 views)
Last post by: Will on 09-11-2013 07:14 AM
FieroJosh1993
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Report this Post09-10-2013 11:06 PM Click Here to See the Profile for FieroJosh1993Click Here to Email FieroJosh1993Send a Private Message to FieroJosh1993Edit/Delete MessageReply w/QuoteDirect Link to This Post
Hey guys, quick question, are the main bearing bolts torque to yield or standard bolts?? I couldn't find the spec in Alldata or Mitchel on Demand5.

Thanks
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trotterlg
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Report this Post09-10-2013 11:22 PM Click Here to See the Profile for trotterlgClick Here to Email trotterlgSend a Private Message to trotterlgEdit/Delete MessageReply w/QuoteDirect Link to This Post
I think that is somewhat debatable. The torque specs are "X" ft pounds plus "X" degrees. My experience is that the torque required to go the the torque plus degrees keeps increasing, so the bolt is not really being torqued to yeald. In a torque to yeald, when tightening a bolt you get to a point where tightening it down more does not require more torque because the bolt is streaching. Personally I don't think they really are torque to yeald, I have a built 3100 that I re-used the rod and main bolts in and I have turned it over 7K and it is still together, so I would say there was no ill effects from the re-use. I have never heard of a failure that is attributed to this except maybe one of the stories like "my wifes sister's boyfriend had a friend that knew a guy that had a problem in Flordia once 4 years ago". Larry
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Fieroking
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Report this Post09-11-2013 12:27 AM Click Here to See the Profile for FierokingClick Here to visit Fieroking's HomePageClick Here to Email FierokingSend a Private Message to FierokingEdit/Delete MessageReply w/QuoteDirect Link to This Post
The bolts on the Fiero engines are not torque to yield. They are standard bolts.

Joe Sokol

------------------
85 SE Daily driver with a 3.4 DOHC OBD II
88 Formula/GT 4.9 Allante Intake (My Baby)
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Will
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Report this Post09-11-2013 07:14 AM Click Here to See the Profile for WillClick Here to Email WillSend a Private Message to WillEdit/Delete MessageReply w/QuoteDirect Link to This Post
Torque + Angle is a method achieve a pull on the bolt that is more precise than torque alone.
A Torque + Angle procedure by itself does NOT indicate a torque to yield condition.

 
quote
Originally posted by trotterlg:

In a torque to yeald, when tightening a bolt you get to a point where tightening it down more does not require more torque because the bolt is streaching.


This is not the case. The point of torque to yield is to achieve the maximum possible clamp load from a bolt. The bolt ends up permanently deformed, but the torque to get to that point is always increasing.

Also: www.dictionary.com
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