When the locks are properly seated, only half of the lock will be visible above the groove. Most pistons that require spiral locks will need four locks per piston, two at each end of the pin (check with your piston supplier).
When installing Spiro locks, grip each end of the lock and pull apart (approx. 3/8˝-7/16˝). The lock will resemble a small coil (Figure 1). The lock can then be spiraled into place almost as if you were screwing them into a groove (Figure 2).
WARNING: It is important that the correct numbers of locks are installed in each piston or severe engine damage may occur. Do not over stretch Spiro locks and do not reuse Spiro locks.
Tech Tip courtesy of JE Pistons.