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Connecting Rod Bolt Question

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Csarneson

Csarneson

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I am a rookie rebuilder (though I will have some experienced help when I actually assemble) and just got my block back from the shop. I realized today that two of my rod bolts are missing the little locking pins that normally sit at 45 degrees. They must have broken off 40 years ago when the engine was disassembled. IMG_0330.jpgI hope that is visible. So 10 of my 12 bolts are fine. These suckers are speedy so I don't want to buy 12 if I don't have to. If I buy just 2 will I experience balance problems? Are those pins even necessary if a clamp could hold them tight when torquing? Suggestions? Anybody have a couple laying around that they'd sell for a reasonable price? Thanks in advance. You guys are invaluable.

Chris in WY
 
Csarneson said:
...will I experience balance problems? Are those pins even necessary if a clamp could hold them tight when torquing? Suggestions? Anybody have a couple laying around that they'd sell for a reasonable price? Thanks in advance. You guys are invaluable. Chris in WY
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Were the rods balanced with the original bolts? If so, get 2 replacements and compare weights with the originals; chances are they'll be close enough to not matter or you could take a little metal off the heavier ones to maintain balance. If the rods weren't balanced to begin with it probably won't make much difference.

I don't know if the rods were even balanced--or balanced meticulously--at the factory. My builder had to take some metal off a couple of mine to get them balanced.
 
I'd fit new ones throughout as a matter of course since you have no guarantee of previous use regarding load, or proper torque. Also rods are usually balanced end for end with a little rig that allows the mass of the big and little ends to be matched not just the overall mass. Usually the bolts are within a few micrograms of each other in mass if they come from the same supplier.

Andy
 
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