Brian Brower
Member
It's probably posted somewhere. I would like to know how tight I should tighten the head bolts on my China two stroke. I took it off to install a copper gasket and I don't want to over tighten it.
It's posted somewhere
- Thread starter Brian Brower
- Start date
Tyler6357
Well-Known Member
15 foot pounds
Brian Brower
Member
Ok thanks
Brian Brower
Member
15 doesn't seem like much
gary55
Well-Known Member
It's enough. More than I give them. But others on here who I trust know what they are talking about go 15. I go inch lbs. at 168.
Frankenstein
Deceased - Frankenstein 1991 - 2018
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Beam wrench soup, one of my favorites.
15 pounds an inch is where the pot metal starts to give way to the steel headbolts. The actual tension is probably much higher, and the solid components make a good little box for gas and air to explode in.
You could always make a brass head gasket (Lowe's sells small plates of brass) that you know the crush characteristics of, then torque it down, pull it back out and measure the difference in thickness across the total crush area. That will give you a ballpark of how much real tension the 4 bolts produce.
The torque wrench isn't really measuring the actual tension of the bolt, it really couldn't, but it does tell us SOMETHING... The 15 in/lb is just saying how much force the threads are resisting being pulled apart by. Best example is the origin of the wrench, was used for tightening water pipes together, which you don't tighten to stretch the piping between 2 places with large amounts of force..
15 pounds an inch is where the pot metal starts to give way to the steel headbolts. The actual tension is probably much higher, and the solid components make a good little box for gas and air to explode in.
You could always make a brass head gasket (Lowe's sells small plates of brass) that you know the crush characteristics of, then torque it down, pull it back out and measure the difference in thickness across the total crush area. That will give you a ballpark of how much real tension the 4 bolts produce.
