Follow along with the video below to see how to install our site as a web app on your home screen.
Note: This feature may not be available in some browsers.
Normal
No. Waisted stem fasteners are designed to work within their plasticity, ie they stretch and then contract again to retain their original length and integrity.Hence the use on things like heads and barrels, they stretch with heat, and return to their original length, maintaining clamping force all the time.If you use fasteners that are too inflexible in this application, then when the alloy expands, the heads of bolts can ‘dig in’ to the alloy head, and / or gaskets compress too much, then when it cools down, you have head bolts that are no longer clamping with the correct torque.This is a fairly common problem on racing / hard used old Nortons and Triumphs.I have no idea, but I wonder if those stainless studs on 961s were actually internationally specified with the coefficient of expansion in mind.
No. Waisted stem fasteners are designed to work within their plasticity, ie they stretch and then contract again to retain their original length and integrity.
Hence the use on things like heads and barrels, they stretch with heat, and return to their original length, maintaining clamping force all the time.
If you use fasteners that are too inflexible in this application, then when the alloy expands, the heads of bolts can ‘dig in’ to the alloy head, and / or gaskets compress too much, then when it cools down, you have head bolts that are no longer clamping with the correct torque.
This is a fairly common problem on racing / hard used old Nortons and Triumphs.
I have no idea, but I wonder if those stainless studs on 961s were actually internationally specified with the coefficient of expansion in mind.
