Tomos Riders Forum

V8s that run in the Bathurst 1000 subject their pistons to 9,000g. Even if a circlip only weighs a gram placing gap at 90º to piston travel will subject it to a closing force of 4.5kg (the other half of the circlip is forced into the groove). This constant flexing will eventually lead to fatigue failure.

Never twist  a circlip  during fitting. The circlip  must enter the pin bore and groove squarely and be under sufficient tension when fitted to prevent rotation by finger pressure . The open end of the circlip  should be installed towards the bottom of the piston. Under no circumstances should the open end of the circlip be positioned to either side of the vertical. Installation in this manner could result in their becoming dislodged owing to  the compressive forces of  inertia acting on them