TM 5-4310-393-14 Max. Item Size Size Perm. Remarks (In) (mm) Wear (in) Undersize. 1.6339 415 Piston Piston diameter. Oversize. Length of piston. 2.8724 +0.1968/ +0.0393 3.2283 72.96 +0.5/ +0.1 82.0 Cylinder Bore diameter. 2 8744 Roughness (RA). Oversize 2.8740/ 0.0197/ +0.0393 73 00/ 73.01 0.9/1.3 +0 5/ +1.0 Up to 0.0006 in 0.15mm Table 5-4.  Piston Ring Data Groove No. Designation Dimension (mm) Gap (mm) Nom. Max. I R-ring (barrel-machined) if CRB Standard Oversize 73 x 2 74 x 2 0.20 0.45 0.8 0.8 II M-compr-ring(taper faced) Standard Oversize 73 x 2 74 x 2 0.25 0.45 1.5 1.5 III G-ring (double beveled oil control ring) Standard Oversize 73 x 4 74 x 4 0.20 0.45 1.5 1.5 5-6. DIESEL ENGINE. A INTRODUCTION This paragraph contains repair and maintenance instructions for the Direct Support Level on the Diesel Engine 5-5