title: Isuzu 6H engine
text: # Isuzu 6H engine
  
  The Isuzu 6H is a family of inline-6 cylinder Diesel engine installed in Isuzu medium duty trucks, and also installed in GM medium-duty trucks as the Duramax LG4. It is mated to the Allison 2500, 3000 and 3500 Series transmissions.
  
  ## Engine Specifications
  
  6HK1/Duramax LG4
  
  * Displacement: 7.8 to 7.8 L; 475.1 to 475.4 cu in (7,785 to 7,790 cc)
  * Bore and stroke: 115 mm × 125 mm (4.53 in × 4.92 in)
  * Block: gray iron
  * Cylinder head: cast iron
  * Fuel cutoff: 2400 rpm
  * Aspiration: Turbocharged and Intercooled
  * Valvetrain: SOHC, 24 Valve
  * Compression: 17.5:1 (17.0:1 for 300 hp (224 kW) motor)
  * Injection: high-pressure common-rail direct injection
  * Power / Torque: 200 bhp (149 kW) to 300 bhp (224 kW), 520 lb⋅ft (705 N⋅m) to 860 lb⋅ft (1,166 N⋅m)
  
  6HH1
  
  * Displacement: 8,226 cc (8.226 L; 502.0 cu in)
  * Bore and Stroke: 115 mm × 132 mm (4.5 in × 5.2 in)
  * Aspiration: Naturally Aspirated
  * Valvetrain: OHC 24 valve
  * Compression Ratio: 18.5:1
  * Injection: Reformed Bosch, Inline Injection Pump with Automatic Timer and All-Speed Mechanical Governor
  * Power / Torque: 173–200 hp (175–203 PS) and 47–51 kg⋅m (340–370 lb⋅ft)
  
  6HE1
  
  * Displacement: 7,127 cc (7.127 L; 434.9 cu in)
  * Bore and Stroke:110 mm × 125 mm (4.3 in × 4.9 in)
  * Aspiration: Naturally Aspirated and Turbocharged
  * Valvetrain: Direct Injection 24 valve
  * Compression Ratio: 16.9:1
  * Injection: Direct Injection
  * Power / Torque: 165–260 hp (167–264 PS) and 46–77 kg⋅m (450–760 N⋅m; 330–560 lb⋅ft)
  
  ## Engine Variants
  
  | Model | Displacement | Output | Notes |
  | - | - | - | - |
  | 6HE1-N | 7.1 L; 434.9 cu in (7,127 cc) | 175 PS (129 kW) | |
  | 6HE1-S | 7.1 L; 434.9 cu in (7,127 cc) | 195 PS (143 kW) | |
  | 6HE1-TCN | 7.1 L; 434.9 cu in (7,127 cc) | 220 PS (162 kW) | |
  | 6HE1-TCS | 7.1 L; 434.9 cu in (7,127 cc) | 250 PS (184 kW) | |
  | 6HH1-N | 8.2 L; 502.0 cu in (8,226 cc) | 175 PS (129 kW) | |
  | 6HH1-C | 8.2 L; 502.0 cu in (8,226 cc) | 185 PS (136 kW) | |
  | 6HH1-S | 8.2 L; 502.0 cu in (8,226 cc) | 210 PS (154 kW) | |
  | 6HL1-N | 7.2 L; 437.3 cu in (7,166 cc) | 180 PS (132 kW) | |
  | 6HL1-S | 7.2 L; 437.3 cu in (7,166 cc) | 205 PS (151 kW) | |
  | 6HK1-TCR | 7.8 L; 475.4 cu in (7,790 cc) | 205 PS (151 kW) | |
  | 6HK1-TCN | 7.8 L; 475.4 cu in (7,790 cc) | 240 PS (177 kW) | |
  | 6HK1-TCC | 7.8 L; 475.4 cu in (7,790 cc) | 260 PS (191 kW) | |
  | 6HK1-TCS | 7.8 L; 475.4 cu in (7,790 cc) | 280 PS (206 kW) | |
  | 6HK1-TCH | 7.8 L; 475.4 cu in (7,790 cc) | 300 PS (221 kW) | |
  | Duramax LG4 7800 | 7.8 L; 475.4 cu in (7,790 cc) | 275 PS (202 kW) | used in GMC medium-duty trucks |
  
  ## Vehicles
  
  * Isuzu F-Series
  * Chevrolet T-Series
  * Isuzu H-Series
  