Onan 7NHM-FA/26105F - 3 Dimensions and Clearances

Section 3. Dimensions and Clearances
MODELS
BGM NHM
CYLINDERS AND
All clearances listed at 70° F
(21 o C) room temperature.
PISTON ASSEMBLY
Values are in inches (millimeters) unless specified
otherwise. Dimensions apply to Specs A, B and C
gensets except as indicated.
Cylinder Bore
3.2490-3.2500
3.5625-3.5635
(Std size honed) (82.525-82.550 mm)
(90.488-90.513 mm}
Cylinder Taper 0.005
0.005
(Max} (0.13 mm) (0.13 mm)
Cylinder Out
Of 0.003
0.003
Round (Max) (0.076 mm)
(0.076 mm)
Clearance In 0.0044-0.0066
0.0070-0.0090
Cylinder (0.112-0.168 mm)
{0.178-0.229 mm)
Ring Gap (top and 0.008-0.018
0.009-0.019
second rings) {0.20-0.46 mm)
(0.23-0.48 mm)
Piston Ring
#1 (top) Spec A, B sets: 0.080-0.081
0.080-0.081
Groove Width
(2.03-2.06 mm) (2.03-2.06 mm)
Spec C sets: 0.0602-0.0612
0.0602-0.0612
(1 .53-1.55 mm)
(1.53-1.55 mm)
Piston Ring
#2
Spec A, B sets: 0.080-0.081
0.080-0.081
Groove Width
(2.03-2.06 mm)
(2.03-2.06 mm)
Spec C sets: 0.0602-0.0612
0.0602-0.0612
(1.53-1 .55 mm)
(1.53-1.55 mm)
Piston Ring
#3
Spec A, B sets: 0.188-0.189
0.188-0.189
Groove Width (4.78-4.80 mm)
(4.78-4.80 mm)
Spec C sets: 0.1193-0.1203
0.1193-0.1203
(3.03-3.06 mm)
(3.03-3.06 mm)
Piston Pin 0.6875-0.6877
0. 7500-0.7502
Diameter
(17.46-17.47 mm)
(19.05-19.06 mm)
Piston Pin Clearance 0.0002-0.0007
0.00005-0.00055
In Rod
(0.005-0.018 mm)
(0.001-0.014 mm)
Connecting Rod
0.0020-0.032
0.0020-0.0160
Side Clearance
(0.051-0.813 mm)
(0.051-0.406 mm)
Connecting Rod
0.0020-0.0033
0.0005-0.0028
Bearing Clearance (0.051-0.084 mm)
(0.013-0.071 mm)
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3-1