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Back in September I out a motor on a motor stand no trouble but now, I have a different motor stand and the thing can't go wide enough to fit all 4 on the motor so i tried 3 and my grade 5 bolts all bent lol. The hardware store guy said grade 5 cus grade 8 would snap.

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You may be better off modifying the stand. Also, if it doesn't go wide enough, it may be too small for your engine. A 4.0 (or any straight six) is very long and puts a huge moment onto its mounting points when only supported at one end.

 

And as to the notion of grade 8 bolts being brittle and breaking? Pure poppycock. One of those old-man myths that even some of the most respected people in automotive circles keep regurgitating.

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The "grade 8 bolts snap, grade 5 bolts bend" myth is stupid Facebook bullcrap and anyone who repeats it needs to shut up and engage their brain before they engage their mouth. You probably shouldn't believe anything else people who repeat it have to say either.

 

Grade 5 bolt yield strength (in other words, the  stress at which the bolt begins to noticeably deform): 81,000-92,000 psi depending on size. Tensile strength (the most stress the bolt can take) of 120-105ksi depending on size.

Grade 8 bolt yield strength: 130,000 psi. A grade 5 bolt of the same size will already have broken by the time a grade 8 bolt yields.

 

Maybe I should make a list of all this BS bad advice you see floating around and explain the truth?

 

jAZHpmH.gif

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The "grade 8 bolts snap, grade 5 bolts bend" myth is stupid Facebook bullcrap and anyone who repeats it needs to shut up and engage their brain before they engage their mouth. You probably shouldn't believe anything else people who repeat it have to say either.

 

Grade 5 bolt yield strength (in other words, the  stress at which the bolt begins to noticeably deform): 81,000-92,000 psi depending on size. Tensile strength (the most stress the bolt can take) of 120-105ksi depending on size.

Grade 8 bolt yield strength: 130,000 psi. A grade 5 bolt of the same size will already have broken by the time a grade 8 bolt yields.

 

Maybe I should make a list of all this BS bad advice you see floating around and explain the truth?

 

jAZHpmH.gif

I thought everything on the internet was true :wall:

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