Re-use con rod bolts/nuts?

My 2 cents,
As a poor grad student I did a refresh on an M10 (head job, piston rings, bearings, etc), and reused all the old fasteners. I beat on that motor mercilessly for 4 years and 20k miles, and it ran like new till the day I parted it out (rust).

And I used torque not angle, because that’s what my Haynes manual said.

20 years later, $200 in new ARP fasteners seemed like really cheap insurance on an XK motor rebuild. This time I followed the instructions from the fastener company.
 
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Gary

Where did you get the info that rod bolts on older BMW's are "stretch" bolts? I have reused rod bolts on probably 98% of the many rebuilds that I have done over the years. Never had a rod bolt issue.

Thanks, Rick
 
stphers said:
Gary

Where did you get the info that rod bolts on older BMW's are "stretch" bolts? I have reused rod bolts on probably 98% of the many rebuilds that I have done over the years. Never had a rod bolt issue.

Thanks, Rick
Click to expand...
Rick,
I had never had a timing chain issue either.... until it broke, recently.

My mechanic friend and consultant for the crazy things I do to engines told me this...... but he says many reuse them. Important that they were never angle torqued like in the old days. Which may mean early M30 motors. I've also heard but never bothered to look up that it says this in the blue book of torques specs put out by BMW. TIS = Technical Information System. Here's the guys on myE28.com hashing this over. Best reference for all things M30. https://www.mye28.com/viewtopic.php?t=44333

He is the best classic mechanic I know with over 40 years of experience and was an official BMW trainer of mechanics for many years.
So for $50 you can replace them all and never worry.
 
stphers said:
Gary

Where did you get the info that rod bolts on older BMW's are "stretch" bolts? I have reused rod bolts on probably 98% of the many rebuilds that I have done over the years. Never had a rod bolt issue.

Thanks, Rick
Click to expand...
I found it.

You can download for free.
Good resource for all things m30 engines.

Section 11 24.

Connecting rod bolts Replace, wash and oil conrod bolts M10/M30 55 Nm

 
At the risk of stirring the pot, use of the term "replace" is admittedly ambiguous, but contextually, it can be interpreted to mean "re-use." Otherwise, why does the same source specify: "fit new cylinder head bolts," instead of merely specifying "replace?"


FWIW, previous thread regarding torque-to-yield head bolts. >> https://e9coupe.com/forum/threads/question-to-retorque-or-not-retorque-the-head-bolts.10288/


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tochi said:
At the risk of stirring the pot, use of the term "replace" is admittedly ambiguous, but contextually, it can be interpreted to mean "re-use." Otherwise, why does the same source specify: "fit new cylinder head bolts," instead of merely specifying "replace?"


FWIW, previous thread regarding torque-to-yield head bolts. >> https://e9coupe.com/forum/threads/question-to-retorque-or-not-retorque-the-head-bolts.10288/


View attachment 105539


View attachment 105537
Click to expand...
Those Germans, you just never know what they mean. Interpret as you see fit.
 
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