AMS Piston Ring Squaring Tool

The AMS Piston Ring Squaring Tool is a must for anyone building or replacing a motor that requires file fitting the piston rings. To insure proper measurements, you must set your ring squarely inside the bore. The problem with doing this by hand is you can never insure that the ring is properly square which can lead to improper measurements. The AMS Piston Ring Squaring Tool takes all your worries away! Due to the stepped edge of the AMS tool, you can rest assured that the rings will be square to the cylinder bore and you will get a precise measurement every time. This black anodized double sided tool will fit a number of engines. One side will fit 85mm to 87mm and the second side will fit 87.5mm to 88mm. This should easily cover any 4G63, 4G64, or 4B11 motor out there!


  • Mitsubishi 4G63 / 4G64
  • Mitsubishi 4B11
  • Engines with bore size of 85mm-87mm
  • Engines with bore size of 87.5mm-88mm

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The goal of AMS is to provide the highest quality, best performing products available.
By utilizing research and development and rigorous testing programs AMS will never compromise the quality or performance of our products.

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On all orders over $199.99 in the lower 48.*Freight items not included*