Stretched conrod bolt

PugMonkey

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Hi all,
Back into building my engine but struck an issue. I have stretched a conrod bolt. What can I do? New conrod or can an engineer replace the thread? Can't post a Pic yet.

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Buy a new conrod bolt. They aren't very expensive. How do you know you stretched it? Were you using a conrod micrometer?
 
I was torquing it down and it just didn't want to tighten so I undid the nut to discover the stretch. Torque used was 39 ft lb from memory

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Just as an aside, years back we used to prepare vintage racing engines with new hi tensile Allen head socket bolts secured with hi tensile nylock style nuts as you could not buy the hi tensile replacement conrod bolts, they worked better than trying to use old deformed conrod bolts, none of the Allen bolts failed in service. here is a link to available similar hi tensile similar bolts.

https://www.bing.com/images/search?q=Bolt+Tensile+Strength+Tables&FORM=RESTAB

Ken
 
It sounds like you've "stripped" the thread rather than stretched the bolt. Stuffed nether the less. You could either buy one new rod bolt & nut from Peugeot, or a complete set of ARP bolts from someone like Rocket Industries. I'd probably do the later. Price will be similar I'd expect.
 
I'd also replace the clutch pressure plate bolts, these do stretch as I have found.
 
Pic. Thread is not stripped. I have another con rod to use. 1565253581649.jpeg

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Definitely past it's yield point! You don't need a micrometer to work that out. Great steel though.
 
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