Oops on the main cap torque

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rub2stix

rub2stix

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I misread the torque spec for the main caps on the 318 we're building. I torqued them to 100 ft/lbs instead of 85.

Should I back off and re-torque? Or just let it be? Or get new main bolts and re-do? Hard to imagine that just 15 extra ft/lb would stretch the bolt too much, but I'll defer to those of you wiser than I.

Grateful for you wisdom, I am,
JD
 
I sure would back them off,& re-torque. Did you check clearances,before final assembly?
 
Once the caps are torqued and the bearing crush is set tightening them down more won't effect the clearances. It might effect bolt stretch but main bolts are pretty hefty. In fact some torque wrenches could be off by that much and you'd never know it. If the engine is on the stand with the oil pan off I would back them off and re-torque. Otherwise just leave them. tmm
 
If you got them torqued down and the crank spins freely, then I wouldn't sweat it. It's not worth an extra clamp load cycle on them to retorque them unless it makes your crank tight.

The bolts have already stretched from that torque cycle, retorquing them will only stretch them more for the new torque cycle. I would let it go if the crank spins freely, it won't hurt.

As stated above, the extra torque will not affect bearing crush, just stretch the bolts slightly a little more.

If you are worried about it and want to retorque them for piece of mind, it us up to you. I would let it go myself.
 
It was align bore at spec,, I wouldn't know if 100 would distort the block,, but I wouldn't take the chance either,, jmo
 
rub2stix said:
I torqued them to 100 ft/lbs instead of 85.
Click to expand...

Let me expain it this way.

For every spec there is a tolerance. For a torque of 85 ft*lb there should be a tolerance about +/- 10 ft*lb. Therefore the allowable torque spec is 75 - 95 ft*lb. He is only 5 ft*lb over that, it won't make that much difference, Let it go.

Retorquing the bolts will only stretch them more than they already are. If you want the piece of mind to retorque them, then replace the bolts and retorque them.

The little bit that he's slightly over will not make that much difference and won't stretch them as much as retorquing them will...
 
It's an extra 15 LB FT. Big whoop. It ain't gonna hurt a thing. Leave it alone.
 
I would leave them be, and with regard to stretch, since they are not a torque to yield fastener and it would take ALOT more than 100lb-ft of torque to stretch them to yield.

Finish putting it together, fire it up and burn rubber!!!
 
I did, in fact check clearances (at the same 100 ft/lbs) before assembly. And it looks to me that I'm the first one in the motor, so they haven't really had a lot of clamp load cycles. Besides, the assembly pass had new bolts on #2 and #4 mains for the windage tray.

I just went out to the garage and she spins very smoothly and freely. So, I'm gonna "set the toe and let 'er go!", in other words, leave it alone and run it.

Thanks all of y'all for your quick input! This list ROCKS! You may make a Mopar convert of me yet! (ex-Blue Oval, then ex-BowTie guy here!)

Comforted, I am,
JD
 
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