262 cid / 4.3L Gen + Marine Engine Specifications

 

Unit of Measurement

 In. (mm) 

 

Displacement

262 CID (4.3 Liter) 

Bore 

4.00 (101.6) 

Stroke

3.48 (88.39)

 Compression Ratio 

9.3:1 

Heads 

Cast Iron

Intake Manifold

Cast Iron

Block

Cast Iron (2 Bolt Main Bearing Caps)

Rods

Forges Steel 

Pistons

Cast Aluminum 

Crankshaft 

Cast Iron

Camshaft 

Steel

 

 


 

 

 CYLINDER BORE 

Diameter

4.0007-4.0017(101.618-101.643) 

Out of Round

 

Production 

.001 (0.025) Maximum

Service

.002 (0.051) Maximum 

Taper

Production

Thrust Side

.0005 (0.012) Maximum 

Relief Side 

.001 (0.025) Maximum 

Service

.001 (0.025) Maximum 

 

PISTON CLEARANCE

Production

.0007-.002 (0.017-0.05)

Service

.0024 (.001)

 

PISTON RING: COMPRESSION (MEASURE IN CYLINDER BORE)  

Groove Clearance

Production

Top

.02-.06 (0.51-1.52)

2nd

.04-.08 (1.02-2.03)

Service

.0042 (0.107) Maximum

Gap

 

Top

.010-.016 (0.25-0.40)

2nd

.018-.026 (.046-.066) Maximum

Service

.06-.035 (1.524-0.88) Maximum

 

PISTON RING: OIL 

 

Groove Clearance

Production

.002-.007 (0.51-0.20)

Service

.02-.08 (0.51-2.032)

Gap

Production

.015-.050 (0.38-1.27)

Service Limit

.009-.065 (0.23-1.65)

 

PISTON PIN 

Diameter

.9267-.9271 (23.545-23.548)

Clearance

Production

.0002-.0007 (0.005-0.0178)

Service Limit

.001 (0.025) Maximum

Fit in Rod

.0008-.0016 (0.021-0.040) Interference

 

CRANKSHAFT  

Main

Journal

Diameter

No. 1

2.4488-2.4495 (62.199-62.217)

No. 2, 3

2.4485-2.4494 (62.191-62.215)

No. 4

2.4479-2.4489 (62.179-62.203)

Taper

Production

.0003 (0.007) Maximum

Service

.001 (0.025) Maximum

Out of Round

Production

.0002 (0.005) Maximum

Service

.001 (0.025) Maximum

Main Bearing

Clearance

Production

No. 1

.0008-.0020 (0.020-0.051)

No. 2, 3, 4

.001-.025 (0.025-0.635)

Service

No. 1, 2, 3, 4

.001-.002 (0.030-0.051)

Crankshaft End Play

.002-.008 (0.05-0.20)

Connecting Rod

Journal

Diameter

2.2487-2.2497 (57.117-57.142)

Taper

Production

.0003 (0.007) Maximum

Service

.001 (0.025) Maximum

Out of Round

Production

.0002 (0.0051) Maximum

Service

.001 (0.025) Maximum

Rod Bearing Clearance

Production

.0013-.0035 (0.033-0.088)

Service

.001-.003 (0.025-0.076)

Rod Side Clearance

.006-.017 (0.15-0.43)

Crankshaft Runout

.001 (0.025) Maximum

 

VALVE SYSTEM 

Lifter

Hydraulic Roller

Rocker Arm Ratio

1.50 to 1

Valve Lift

Intake

.414 (10.52)

Exhaust

.428 (10.87)

Valve Lash (Intake & Exhaust)

Net Lash No Adjustment

Face Angle (Intake & Exhaust)

45°

Seat Angle (Intake & Exhaust)

46°

Seat Runout (Intake & Exhaust)

.002 (0.05) Maximum

Seat Width

Intake

.035-.060 (0.89-1.52)

Exhaust

.062-.093 (1.58-2.38)

Stem

Clearance

Production

Intake

.0010-.0027 (0.025-0.069)

Exhaust

Service

Intake

.001 (0.025) Maximum

Exhaust

.002 (0.51) Maximum

Stem Diameter

Intake

.34-.3407 (8.636-8.653)

Exhaust

Valve Margin (Intake & Exhaust)

.031 (0.79)

 

VALVE SPRING 

Valve

Spring

Free Length

2.03 (51.6)

Pressure

Valve Closed

76-84 Lb. (338-374 N) at 1.7 in (43.16 mm)

Valve Open

187-203 Lb. (832-903 N) at 1.27 in (32.25 mm)

Installed Height

1.690-1.710 in (42.93-43.43 mm)

 

CAMSHAFT AND DRIVE 

Lobe Lift +

.002(0.051) 

Intake

.286-.290 (7.26-7.36)

Exhaust

.292-.296 (7.42-7.52)

Journal Diameter

1.8682-1.8692 (47.452-47.478)

Journal Out of Round

.001 (0.025) Maximum

Camshaft Runout

.002 (0.051) Maximum

Camshaft End Play

.001-.009 (0.0254-0.2286)

Timing Chain Deflection

.375 (9.5) from taut position [total .75 (19)]

 

FLYWHEEL 

Runout

.008 (0.203) Maximum

 

CYLINDER HEAD 

Gasket Surface Flatness 

.010 (0.254) Overall Maximum 

 

BALANCE SHAFT 

Front Bearing Journal

2.1648-2.1654 (54.985-55.001)

Rear Bearing Journal 

1.4994-1.500 (38.084-38.100) 

Rear Bearing Journal Clearance

.001-.0036 (.025-.091) 

 


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