Field of application: For Jims Twin Cam standard size piston of 120", 131", and 131" engines, with 4.125" or 4.130" bore
This tool makes measuring ring end gap faster, more accurate and eliminate the guess work. The flanged design allows the piston ring to fit squarely in cylinder bore every time. This is the first tool to desinged to be able to test oil ring gaps by a proprietary cutout feature. Just install any ring, top, 2nd, or oil control rails on the tool. Install tool into a cylinder bore and then view the ring end gap in the “Key Slot”. Use a feeler gauge to get your end gap measurement. Each side of the tool is made for checking a standard size piston rings.