FOR MODELS: JGI, JGM, JGN, JGP AND JGQ SECTION 1 - DESIGN SPECIFICATIONS & DATA
9/08 PAGE 1-11
Piston Ring and Packing Ring Side Clearance, Inches (mm)
The standard side clearance in inches (mm) for JG, M, P and SP class cylinders - piston
rings and packing rings, when new, are as follows:
TABLE 1-4 NEW CONVENTIONAL PISTON RING SIDE CLEARANCE, INCHES (mm)
3/16 (4.76)
0.187 to 0.189
(4.75 to 4.80)
0.005 to 0.009
(0.13 to 0.23)
0.004 to 0.008
(0.10 to 0.20)
1/4 (6.35)
0.250 to 0.252
(6.35 to 6.40)
0.005 to 0.009
(0.13 to 0.23)
0.004 to 0.008
(0.10 to 0.20)
3/8 (9.53)
0.375 to 0.377
(9.53 to 9.58)
0.007 to 0.011
(0.18 to 0.28)
0.004 to 0.008
(0.10 to 0.20)
3/4 (19.05)
0.750 to 0.752
(19.05 to 19.10)
0.014 to 0.019
(0.36 to 0.48)
0.006 to 0.010
(0.15 to 0.25)
TABLE 1-5 NEW RIDER RING PISTON RING SIDE CLEARANCE, INCHES (mm)
3/16 (4.76) 0.187 to 0.189 (4.75 to 4.80) 0.007 to 0.012 (0.18 to 0.30)
1/4 (6.35) 0.250 to 0.252 (6.35 to 6.40) 0.008 to 0.013 (0.20 to 0.33)
3/8 (9.53) 0.375 to 0.377 (9.53 to 9.58) 0.008 to 0.013 (0.20 to 0.33)
1/2 (12.70) 0.500 to 0.502 (12.70 to 12.75) 0.008 to 0.013 (0.20 to 0.33)
3/4 (19.05) 0.750 to 0.752 (19.05 to 19.10) 0.008 to 0.013 (0.20 to 0.33)
TABLE 1-6 PACKING RING SIDE CLEARANCE, INCHES (mm)
0.375 to 0.377
(9.53 to 9.58)
0.011 to 0.014
(0.28 to 0.36)
0.011 to 0.015
(0.28 to 0.38)
N/A
0.006 to
0.008
(0.15 to
0.20)
0.447 to 0.449
(11.35 to 11.41)
N/A N/A
0.013 to 0.018
(0.33 to 0.46)
0.562 to 0.564
(14.28 to 14.33)
N/A N/A
0.017 to 0.022
(0.43 to 0.56)
0.936 to 0.938
(23.77 to 23.82)
N/A
Zero (0)
a
N/A
NOMINAL
WIDTH
ACTUAL GROOVE
WIDTH
TEFLON ONE-PIECE BRONZE
NOMINAL WIDTH ACTUAL GROOVE WIDTH TWO-PIECE
ACTUAL
GROOVE WIDTH
1 - RING/GROOVE
NON-METAL or CI
2 - RINGS GROOVE
NON-METAL or CI
3 - RINGS/GROOVE
NON-METAL or CI
BRONZE
a. Side loaded “AL” (5) ring type