Piston Selection - GMC T Series 1994 Repair Manual

Figure 42— Engine Block Oil Gallery Hole and Coolant Drain Hole Plugs (7.4L Engines)
Measure
m
• Cylinder out of round and taper. Refer to SECTION
6
A.
Cylinder Bore Reconditioning
6
Refer to SECTION A.
PISTON AND CONNECTING ROD
ASSEMBLIES
For disassembly, cleaning, inspection, and assembly
of these components, refer to SECTION
Measure
• Piston pin diameter and pin to piston clearance.
• Piston to bore clearance and fit pistons as outlined.

PISTON SELECTION

1. Check the used piston to cylinder bore clearance,
as follows:
A. Cylinder bore diameter. Use a telescoping bore
gage, located 65 mm (2 1/2 inches) below the
top of the cylinder bore.
B. Piston diameter. Measure the skirt at a right
angle to the piston pin hole.
C. Subtract the piston diameter from the cylinder
bore diameter to determine piston to bore clear­
ance.
210. PLUG, ENGINE BLOCK COOLANT DRAIN
220. PLUG, OIL FEED HOLE
222
221. PLUG, OIL GALLERY HOLE
222. PLUG, OIL GALLERY HOLE
223. PLUG, OIL GALLERY HOLE
224. PLUG, OIL GALLERY HOLE
225. PLUG, OIL GALLERY HOLE
226. PLUG, OIL GALLERY HOLE
227. PLUG, OIL GALLERY HOLE
D. Locate the piston to bore clearance refer to
6
A.
" Specifications." Determine if the piston to bore
clearance is in the acceptable range.
Important
Each connecting rod and bearing cap should be
marked, beginning at the front of the engine.
Cylinders 1, 3, 5, and 7 are the right bank and
6 8
2, 4, , and are the left bank (when viewed
from the front of the engine). The numbers on
the connecting rod and bearing cap must be on
227
V2888