Chevrolet Silverado / GMC Sierra. Manual — part 225

Measured in Cylinder Bore - Service

Piston Ring-to-Groove Clearance - First
Compression Ring - Production

0.04-0.085 mm

0.00157-0.00335

in

Piston Ring-to-Groove Clearance - First
Compression Ring - Service

0.04-0.085 mm

0.00157-0.00335

in

Piston Ring-to-Groove Clearance - Second
Compression Ring - Production

0.04-0.078 mm

0.00157-0.0031 in

Piston Ring-to-Groove Clearance - Second
Compression Ring - Service

0.04-0.078 mm

0.00157-0.0031 in

Piston Ring-to-Groove Clearance - Oil Control
Ring - Production

0.012-0.2 mm

0.0005-0.0078 in

Piston Ring-to-Groove Clearance - Oil Control
Ring - Service

0.012-0.2 mm

0.0005-0.0078 in

Pistons and Pins

Pin - Piston Pin Clearance-to-Piston Pin Bore -
Production

0.002-0.01 mm

0.00008-0.0004 in

Pin - Piston Pin Clearance-to-Piston Pin Bore -
Service

0.002-0.015 mm 0.00008-0.0006 in

Pin - Piston Pin Diameter

23.952-23.955 mm

0.943-0.943 in

Pin - Piston Pin Fit in Connecting Rod Bore -
Production

0.007-0.02 mm

0.00027-0.00078

in

Pin - Piston Pin Fit in Connecting Rod Bore -
Service

0.007-0.022 mm

0.00027-0.00086

in

Piston - Piston Diameter - Measured Over
Coating

96.002-96.036 mm

3.779-3.78 in

Piston - Piston to Bore Clearance - Production

-0.036 to +0.016

mm

-0.0014 to

+0.0006 in

Piston - Piston to Bore Clearance - Service
Limit With Skirt Coating Worn Off

0.071 mm

0.0028 in

Valve System

Valves - Valve Face Angle

45 degrees

Valves - Valve Face Width

1.25 mm

0.05 in

Valves - Valve Lash

Net Lash - No Adjustment

2008 Hummer H2

2008 ENGINE Engine Mechanical - 6.2L - H2

SEALERS, ADHESIVES, AND LUBRICANTS

Valve Lift - Exhaust

12.72 mm

0.501 in

Valve Lift - Intake

12.72 mm

0.501 in

Valves - Valve Seat Angle

46 degrees

Valves - Valve Seat Runout

0.05 mm

0.002 in

Valves - Valve Seat Width - Exhaust

1.78 mm

0.07 in

Valves - Valve Seat Width - Intake

1.02 mm

0.04 in

Valves - Valve Stem Diameter - Production

7.955-7.976 mm

0.313-0.314 in

Valves - Valve Stem Diameter - Service

7.95 mm

0.313 in

Valves - Valve Stem-to-Guide Clearance -
Production - Exhaust

0.025-0.066 mm

0.001-0.0026 in

Valves - Valve Stem-to-Guide Clearance -
Service - Exhaust

0.093 mm

0.0037 in

Valves - Valve Stem-to-Guide Clearance -
Production - Intake

0.025-0.066 mm

0.001-0.0026 in

Valves - Valve Stem-to-Guide Clearance -
Service - Intake

0.093 mm

0.0037 in

Rocker Arms - Valve Rocker Arm Ratio

1.70:1

Valve Springs - Valve Spring Free Length

52.9 mm

2.08 in

Valve Springs - Valve Spring Installed Height

45.75 mm

1.8 in

Valve Springs - Valve Spring Load - Closed

340 N at 45.75

mm

76 lb at 1.8 in

Valve Springs - Valve Spring Load - Open

980 N at 33.55

mm

220 lb at 1.32 in

Application

Type of Material

GM Part Number

United

States

Canada

Coolant Temperature Sensor Threads

Sealant

12346004

10953480

Cylinder Head Core Hole Plug

Threadlock

12345382

10953489

Cylinder Head Plug

Threadlock

12345382

10953489

Engine Block Coolant Drain Hole Plug

Sealant

12346004

10953480

2008 Hummer H2

2008 ENGINE Engine Mechanical - 6.2L - H2

THREAD REPAIR SPECIFICATIONS

Engine Block - Front/Rear Views

Sealing Washer

Engine Block Front Oil Gallery Plug

Threadlock

12345382

10953489

Engine Block Oil Gallery Plug Sealing

Washers

Sealant

12346004

10953480

Engine Oil Pressure Sensor Threads

Sealant

12346004

10953480

Engine Oil Supplement

Fluorescent Dye

12345795

10953470

Exhaust Manifold Bolts

Threadlock

12345493

10953488

Flywheel/Flex Plate Bolts

Threadlock

12345382

10953489

Fuel Injection Fuel Rail Bolts

Threadlock

12345382

10953489

Ignition Coil Bracket-to-Valve Cover

Studs

Threadlock

12345382

10953489

Ignition Coil-to-Bracket Bolts

Threadlock

12345382

10953489

Intake Manifold Bolts

Threadlock

12345382

10953489

Oil Pan Oil Gallery Plug Threads

Sealant

12346004

10953480

Oil Pan Surface at Front Cover and Rear

Housing

Sealant

12378521

88901148

Thread Repair Component Cleaner

Cleaner

12346139

10953463

Thread Repair Component Cleaner

Cleaner

12377981

10953463

Thread Repair Cutting Oil

Lubricant

1052864

992881

2008 Hummer H2

2008 ENGINE Engine Mechanical - 6.2L - H2

Fig. 1: Engine Block - Front/Rear Views
Courtesy of GENERAL MOTORS CORP.

Engine Block - Left/Right Side Views

Hole

Thread

Size

Insert

Drill

Counterbore

Tool

Tap

Driver

Drill

Depth -

Maximum

mm (in)

Tap Depth

-

Maximum

mm (in)

J 42385-

1

M8 x

1.25

210

206

207

208

209

22.5

(0.885)

17.5

(0.688)

2

M10 x

1.5

215

211

212

213

214

27.5 (1.08)

22.0

(0.866)

3

M10 x

1.5

215

211

212

213

214

Thru

Thru

4

M8 x

1.25

210

206

207

208

209

Thru

Thru

5

M10 x

1.5

215

211

212

213

214

25.0

(0.984)

19.5

(0.767)

6

M10 x

1.5

215

211

212

213

214

32.5

(1.279)

25.0

(0.984)

7

M10 x

1.5

215

211

212

213

214

Thru

Thru

Bolt hole 6 is drilled and tapped for aluminum block applications only.

2008 Hummer H2

2008 ENGINE Engine Mechanical - 6.2L - H2