Engine Mechanical Specifications. GMC Truck GMC C-Series Medium Duty Truck B7 1999

For 1990-2009 cars only

Makes 🢒 GMC_Truck 🢒 1999 🢒 GMC C-Series Medium Duty Truck B7 🢒 Engine 🢒 Engine Mechanical - 7.4L 🢒 Engine Mechanical Specifications

Engine Mechanical Specifications L21(VINB)

Application	Specification
Application	Metric	English
General Data
Engine Type	V-8
Displacement	7.4L	454 CID
RPO	L21
VIN	B
Bore	107.950 mm	4.2500 in
Stroke	101.600 mm	4.0000 in
Compression Ratio	9.0:1
Firing Order	1-8-4-3-6-5-7-2
Spark Plug Gap	0.889 mm	0.0600 in
Cylinder Head
Cylinder Head Engine Block Deck Surface Flatness	0.076 mm	0.0030 in
Exhaust Manifold
Exhaust Manifold Cylinder Head Surface Flatness	0.254 mm	0.0100 in
Lubrication System
Oil Capacity without Filter Change	5.7 liters	6.0 qt
Oil Capacity with Filter Change	6.6 liters	7.0 qt
Oil Pressure (Fully Warmed Oil not Hot)	68.65 kPa @ 600 RPM 172.37 kPa @ 2,000 RPM	10 psi @ 600 RPM 25 psi @ 2,000 RPM
Oil Filter System	Full Flow
Oil Pump Type	Gear Driven
Cylinder Bore
Diameter Production	107.950-107.968 mm	4.2500-4.2507 in
Out-of-Round Production	0.0254 mm (Maximum)	0.0010 in (Maximum)
Out-of-Round Service	0.051 mm (Maximum)	0.0020 in (Maximum)
Taper Production Thrust Side	0.0127 mm (Maximum)	0.0005 in (Maximum)
Taper Production Relief Side	0.0254 mm (Maximum)	0.0010 in (Maximum)
Taper Service	0.0254 mm (Maximum)	0.0010 in (Maximum)
Piston
Piston Diameter	107.891-107.904 mm	4.2477-4.2482 in
Clearance Production	0.0457-0.0762 mm	0.0018-0.0030 in
Clearance Service Limit	0.0457-0.2190 mm	0.0018-0.0048 in
Piston Ring Compression
Top Groove Production Clearance	0.031-0.074 mm	0.0012-0.0029 in
Second Groove Production Clearance	0.031-0.074 mm	0.0012-0.0029 in
Service Limit Groove Clearance	0.0991-0.3050 mm	0.0012-0.0039 in
Top Ring Production Gap	0.254-0.457 mm	0.0100-0.0180 in
Top Ring Service Limit Gap	0.254-0.711 mm	0.0100-0.0280 in
Second Ring Production Gap	0.406-0.609 mm	0.0160-0.0240 in
Second Ring Service Limit Gap	0.406-0.863 mm	0.0160-0.0340 in
Piston Ring Oil Control
Production Groove Clearance	0.127-0.165 mm	0.0050-0.0065 in
Service Limit Groove Clearance	0.127-0.191 mm	0.0050-0.0075 in
Production Gap	0.254-0.762 mm	0.0100-0.0300 in
Service Limit Gap	0.254-1.016 mm	0.0100-0.0400 in
Piston Pin
Diameter	25.132-25.137 mm	0.98945-0.98965 in
Clearance in Piston Production	0.005-0.017 mm	0.0002-0.0007 in
Clearance in Piston Service Limit	0.005-0.025 mm	0.0002-0.0010 in
Fit in Connecting Rod	0.078-0.053 mm Interference	0.0021-0.0031 in Interference
Crankshaft
Crankshaft Run Out	0.051 mm (Maximum)	0.0020 in (Maximum)
Crankshaft Journal Diameter #1, #2, #3, #4, #5	69.804-69.822 mm	2.7482-2.7489 in
Crankshaft Journal Taper Production	0.010 mm (Maximum)	0.0004 in (Maximum)
Crankshaft Journal Taper Service Limit	0.025 mm (Maximum)	0.0010 in (Maximum)
Crankshaft Journal Out-of-Round Production	0.010 mm (Maximum)	0.0004 in (Maximum)
Crankshaft Journal Out-of-Round Service Limit	0.025 mm (Maximum)	0.0010 in (Maximum)
Crankshaft Bearing Clearance #1 Production	0.043-0.076 mm	0.0017-0.0030 in
Crankshaft Bearing Clearance #2, #3, #4 Production	0.028-0.061 mm	0.0011-0.0024 in
Crankshaft Bearing Clearance #5 Production	0.063-0.096 mm	0.0025-0.0038 in
Crankshaft Bearing Clearance #1, #2, #3, #4 Service Limit	0.025-0.076 mm	0.0010-0.0030 in
Crankshaft Bearing Clearance #5 Service Limit	0.063-0.101 mm	0.0025-0.0040 in
Crankshaft End Play	0.127-0.279 mm	0.0050-0.0110 in
Crankshaft Thrust Wall Width	46.1391-46.2153 mm	1.8165-1.8195 in
Crankshaft Thrust Wall Maximum Runout	0.025 mm	0.001 in
Crankpin Diameter	55.854-55.869 mm	2.1990-2.1996 in
Crankpin Taper Production	0.0127 mm	0.0005 in
Crankpin Taper Service Limit	0.025 mm	0.0010 in
Crankpin Out-of-Round Production	0.013 mm	0.0005 in
Crankpin Out-of-Round Service Limit	0.025 mm	0.0010 in
Rod Bearing Clearance Production	0.028-0.074 mm	0.0011-0.0029 in
Rod Bearing Clearance Service Limit	0.028-0.099 mm	0.0011-0.0039 in
Connecting Rod Side Clearance	0.033-0.584 mm	0.0013-0.0230 in
Camshaft
Camshaft Run Out	0.051 mm (Maximum)	0.0020 in (Maximum)
Lobe Lift Intake	7.115-7.215 mm	0.2801-0.2840 in
Lobe Lift Exhaust	7.171-7.271 mm	0.2823-0.2862 in
Journal Diameter	49.471-49.522 mm	1.9477-1.9497 in
Valve System
Lifter	Hydraulic, Roller Followers
Rocker Arm Ratio	1.70:1
Valve Lash Intake	Net Lash
Valve Lash Exhaust	Net Lash
Face Angle (Intake & Exhaust)	45 degrees
Seat Angle (Intake & Exhaust)	46 degrees
Seat Runout (Intake & Exhaust)	0.051 mm (Maximum)	0.0020 in (Maximum)
Seat Width Exhaust	1.524-2.413 mm	0.0600-0.0950 in
Seat Width Intake	0.762-1.524 mm	0.0300-0.0600 in
Stem Clearance Production Exhaust	0.030-0.077 mm	0.0012-0.0031 in
Stem Clearance Production Intake	0.025-0.0737 mm	0.0010-0.0029 in
Stem Clearance Service Exhaust	0.030-0.124 mm	0.0012-0.0049 in
Stem Clearance Service Intake	0.025-0.094 mm	0.0010-0.0037 in
Valve Spring Pressure Closed	316-351 N @ 46.685 mm	71-79 lb @ 1.8380 in
Valve Spring Pressure Open	1059-1165 N @ 34.213 mm	238-262 lb @ 1.3470 in
Valve Spring Installed Height	46.685-47.479 mm	1.8380-1.8690 in

Engine Mechanical Specifications LP4 (VIN D)

Application	Specification
Application	Metric	English
General Data
Engine Type	V-8
Displacement	7.4L	454 CID
RPO	LP4
VIN	D
Bore	107.950 mm	4.2500 in
Stroke	101.600 mm	4.0000 in
Compression Ratio	9.0:1
Firing Order	1-8-4-3-6-5-7-2
Spark Plug Gap	0.889 mm	0.0600 in
Cylinder Head
Cylinder Head Engine Block Deck Surface Flatness	0.076 mm	0.0030 in
Exhaust Manifold
Exhaust Manifold Cylinder Head Surface Flatness	0.254 mm	0.0100 in
Lubrication System
Oil Capacity without Filter Change	5.7 liters	6.0 qt
Oil Capacity with Filter Change	6.6 liters	7.0 qt
Oil Pressure (Fully Warmed Oil not Hot)	68.65 kPa @ 600 RPM 172.37 kPa @ 2,000 RPM	10 psi @ 600 RPM 25 psi @ 2,000 RPM
Oil Filter System	Full Flow
Oil Pump Type	Gear Driven
Cylinder Bore
Diameter Production	107.950-107.968 mm	4.2500-4.2507 in
Out-of-Round Production	0.0254 mm (Maximum)	0.0010 in (Maximum)
Out-of-Round Service	0.051 mm (Maximum)	0.0020 in (Maximum)
Taper Production Thrust Side	0.0127 mm (Maximum)	0.0005 in (Maximum)
Taper Production Relief Side	0.0254 mm (Maximum)	0.0010 in (Maximum)
Taper Service	0.0254 mm (Maximum)	0.0010 in (Maximum)
Piston
Piston Diameter	107.891-107.904 mm	4.2477-4.2482 in
Clearance Production	0.0457-0.0762 mm	0.0018-0.0030 in
Clearance Service Limit	0.0457-0.2190 mm	0.0018-0.0048 in
Piston Ring Compression
Top Groove Production Clearance	0.031-0.074 mm	0.0012-0.0029 in
Second Groove Production Clearance	0.031-0.074 mm	0.0012-0.0029 in
Service Limit Groove Clearance	0.0991-0.3050 mm	0.0012-0.0039 in
Top Ring Production Gap	0.254-0.457 mm	0.0100-0.0180 in
Top Ring Service Limit Gap	0.254-0.711 mm	0.0100-0.0280 in
Second Ring Production Gap	0.406-0.609 mm	0.0160-0.0240 in
Second Ring Service Limit Gap	0.406-0.863 mm	0.0160-0.0340 in
Piston Ring Oil Control
Production Groove Clearance	0.127-0.165 mm	0.0050-0.0065 in
Service Limit Groove Clearance	0.127-0.191 mm	0.0050-0.0075 in
Production Gap	0.254-0.762 mm	0.0100-0.0300 in
Service Limit Gap	0.254-1.016 mm	0.0100-0.0400 in
Piston Pin
Diameter	25.132-25.137 mm	0.98945-0.98965 in
Clearance in Piston Production	0.005-0.017 mm	0.0002-0.0007 in
Clearance in Piston Service Limit	0.005-0.025 mm	0.0002-0.0010 in
Fit in Connecting Rod	0.078-0.053 mm Interference	0.0021-0.0031 in Interference
Crankshaft
Crankshaft Run Out	0.051 mm (Maximum)	0.0020 in (Maximum)
Crankshaft Journal Diameter #1, #2, #3, #4, #5	69.804-69.822 mm	2.7482-2.7489 in
Crankshaft Journal Taper Production	0.010 mm (Maximum)	0.0004 in (Maximum)
Crankshaft Journal Taper Service Limit	0.025 mm (Maximum)	0.0010 in (Maximum)
Crankshaft Journal Out-of-Round Production	0.010 mm (Maximum)	0.0004 in (Maximum)
Crankshaft Journal Out-of-Round Service Limit	0.025 mm (Maximum)	0.0010 in (Maximum)
Crankshaft Bearing Clearance #1 Production	0.043-0.076 mm	0.0017-0.0030 in
Crankshaft Bearing Clearance #2, #3, #4 Production	0.028-0.061 mm	0.0011-0.0024 in
Crankshaft Bearing Clearance #5 Production	0.063-0.096 mm	0.0025-0.0038 in
Crankshaft Bearing Clearance #1, #2, #3, #4 Service Limit	0.025-0.076 mm	0.0010-0.0030 in
Crankshaft Bearing Clearance #5 Service Limit	0.063-0.101 mm	0.0025-0.0040 in
Crankshaft End Play	0.127-0.279 mm	0.0050-0.0110 in
Crankshaft Thrust Wall Width	46.1391-46.2153 mm	1.8165-1.8195 in
Crankshaft Thrust Wall Maximum Runout	0.025 mm	0.001 in
Crankpin Diameter	55.854-55.869 mm	2.1990-2.1996 in
Crankpin Taper Production	0.0127 mm	0.0005 in
Crankpin Taper Service Limit	0.025 mm	0.0010 in
Crankpin Out-of-Round Production	0.013 mm	0.0005 in
Crankpin Out-of-Round Service Limit	0.025 mm	0.0010 in
Rod Bearing Clearance Production	0.028-0.074 mm	0.0011-0.0029 in
Rod Bearing Clearance Service Limit	0.028-0.099 mm	0.0011-0.0039 in
Connecting Rod Side Clearance	0.033-0.584 mm	0.0013-0.0230 in
Camshaft
Camshaft Run Out	0.051 mm (Maximum)	0.0020 in (Maximum)
Lobe Lift Intake	7.115-7.215 mm	0.2801-0.2840 in
Lobe Lift Exhaust	7.171-7.271 mm	0.2823-0.2862 in
Journal Diameter	49.471-49.522 mm	1.9477-1.9497 in
Valve System
Lifter	Hydraulic, Roller Followers
Rocker Arm Ratio	1.70:1
Valve Lash Intake	Net Lash
Valve Lash Exhaust	Net Lash
Face Angle (Intake & Exhaust)	45 degrees
Seat Angle (Intake & Exhaust)	46 degrees
Seat Runout (Intake & Exhaust)	0.051 mm (Maximum)	0.0020 in (Maximum)
Seat Width Exhaust	1.524-2.413 mm	0.0600-0.0950 in
Seat Width Intake	0.762-1.524 mm	0.0300-0.0600 in
Stem Clearance Production Exhaust	0.030-0.077 mm	0.0012-0.0031 in
Stem Clearance Production Intake	0.025-0.0737 mm	0.0010-0.0029 in
Stem Clearance Service Exhaust	0.030-0.124 mm	0.0012-0.0049 in
Stem Clearance Service Intake	0.025-0.094 mm	0.0010-0.0037 in
Valve Spring Pressure Closed	316-351 N @ 46.685 mm	71-79 lb @ 1.8380 in
Valve Spring Pressure Open	1059-1165 N @ 34.213 mm	238-262 lb @ 1.3470 in
Valve Spring Installed Height	46.685-47.479 mm	1.8380-1.8690 in