How many foot pounds of torque for a high compression CNC head?
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Cannonball3
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I use 12ft pounds, actually 144 inch pounds. I prefer my inch pound torque wrench as its easier to use more accurately.
Shawnandkate8
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I was told by BikeBerry with the aluminum case and 8mm bolts no more than 140in lbs. Also in my experience turning wrenches, that last little grunt you put on it usually breaks something. In this case it would be the crank case. Trust your torque wrench. 140 is fine. Or 12lbs depending on the wrench. And make sure you check the torque after a few warm up/ cool down cycles as aluminum isn’t exactly the strongest metal and if you bought a “kit” motor, then you already know the Chinese head bolts leave much to be desired. Loctite is your friend here.
Cannonball3
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I have had no issues at 144, using that on all brand of engines for years. When these engines first showed up
years ago stud pull was quite common. I havent had any issues for years. Use the 140 if you feel better about it
. Retorque after the first heat cycle. Check ocassionally.
years ago stud pull was quite common. I havent had any issues for years. Use the 140 if you feel better about it
. Retorque after the first heat cycle. Check ocassionally.
12 ft pds IS exactly 144 inch pds, NOT 140...DAMIEN
Shawnandkate8
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That’s what support from BikeBerry told me. First build here so I assumed they knew what they were talking about. I haven’t te checked mine yet as I’ve only ran it a couple times. Is the 4in lbs that precise? I understand the conversion 12in=1ft, but didn’t know the 4 in lbs we’re that critical unless it just boils down to personal preference? I’m no professional mechanic and am a definite newbie at motorized bikes and would definitely love to learn as much as I can. Thanks.
Frogslayer
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Within 4 in lbs is definitely close enough.
Shawnandkate8
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Whew. I was getting a little nervous. I hear these things are temperamental so if someone with experience tells me 144 over 140 I think we’ll maybe they are that delicate. I just didn’t want to snap the bolts out and have to deal with that. Thanks for the heads up guys!
Aikaru
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I have a torque wrench that reads in inch pounds, but it's kinda hard to tell where you're at. One full spin goes from 120 in/lbs to 240 in/lbs. So I don't know which to set it at or how much to spin it from 120 to get to 144.
Frogslayer
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Approximately 45 degrees from 120 should be real close to 145