Cummins 4BT – Base Engine Components Specifications – Cylinder Bore
• Cylinder Bore Diameter Maximum 102.116 mm [4.0203 in] • Out of Round (Maximum) 0.035 mm [0.0014 in] • Taper (Maximum) 0.076 mm [0.003 in]
Category Archives: Cummins 4BT
Cummins 4BT – Base Engine Components Specifications – Cylinder Block
Use a straight edge and feeler gauge to measure the overall flatness of the cylinder block. The overall flatness, must not exceed .076 mm [0.003 in] end-to-end, and .051 mm [.002 in] side-to-side. Visually inspect for any localized dips or imperfections. If present, the cylinder block head deck must be reground. Refer to the Alternative… Read More »
Cummins 4BT – Base Engine Components Specifications – Crankshaft
• Connecting Rod Journal • Journal Out of Round (Maximum) 0.050 mm [0.002 in] • Journal Taper (Maximum) 0.013 mm [0.005 in]
Cummins 4BT – Base Engine Components Specifications – Connecting Rod
• Pin Bore Diameter (Maximum) – Bushing Installed 40.019 MIN 1.5755 40.042 MAX 1.5765
Cummins 4BT – Base Engine Components Specifications – Pistons
• Skirt Diameter 101.823 mm MIN [4.0088 in] 101.887 mm MAX [4.0107 in] • Pin Bore Diameter 40.006 mm MIN [1.5750 in] 40.025 mm MAX [1.5758 in] NOTE: Measure the diameter on a vertical axis only. • Ring Groove (Maximum) Top Groove Use Keystone Gauge Intermediate Groove (Ring Side Clearance) 0.150 mm [0.006 in] Oil… Read More »
Cummins 4BT – Base Engine Components Specifications – Tappets
• Stem Diameter (Minimum at 28 mm height) 15.925 mm [0.627 in]
Cummins 4BT – Base Engine Components Specifications – Camshaft
• Journal Diameter (Minimum) 53.962 mm [2.1245 in] • Valve Lobes (Min. Dia. at Peak of Lobe) Intake 47.040 mm [1.852 in] Exhaust 46.770 mm [1.841 in] • Lift Pump Lobe (Min. Dia. at Peak of Lobe) 35.5 mm [1.398 in]
Cummins 4BT – Base Engine Components Specifications – Gear Train
• Gear Backlash (all gears) 0.08 to 0.33 mm [0.003 to 0.013 in]
Cummins 4BT – Base Engine Components Specifications – Valve Train
Valve Clearance • Intake 0.25 mm [0.010 in] • Exhaust 0.51 mm [0.020 in] Valve Guide Diameter (Maximum) 8.090 mm [0.3185 in] Max 8.019 mm [0.3157 in] Min Valve Stem Diameter (Minimum) 7.94… Read More »
Cummins 4BT – Flywheel Housing and Flywheel
Diagnostics of the flywheel housing and flywheel is normally limited to a visual inspection of the parts for damage or wear. Occasional failure of a starting motor to engage can becaused by damaged teeth on the ring gear. Service ring gears are available for repairing flywheels (refer to procedure 7-23). When troubleshooting a transmission vibration… Read More »