Enter the diameter of your piston and the required height (including all rings) in the FreeCAD Spreadsheet to adapt the model to your engine. You can decrease the diameter by 1mm to ensure sufficient tightening of the tool, but in my case it worked with the exact diameter of the piston.

Shown model corresponds to a Honda GXV340 engine (Ø82mm).

You will need 2 M6 bolts to tighten the tool and compress the rings properly.

Printed in PETD-CF, 0,2mm with concentric infills.