Engine Long Block 4D102 / 4BT / QSB3.9 6731-21-1010/3903920 KOMATSU

Richtone offers to buy: Engine Long Block for Komatsu 4D102 / Cummins 4BT / QSB3.9 Engines (Part Numbers: 6731-21-1010 / 3903920)

✅ In stock – order now!

📄 Product Description:

High-quality OEM long block assembly compatible with Komatsu 4D102 and Cummins 4BT / QSB3.9 diesel engines. Manufactured from premium cast iron and fully assembled with new internal components — crankshaft, pistons, connecting rods, camshaft, cylinder head, and valve system. Designed for reliability, power, and long life under heavy-duty conditions.

🔧 Compatibility (Applications):

Compatible Engines:

• Komatsu: 4D102, S4D102, SA4D102

• Cummins: 4BT, QSB3.9, 4BTA3.9

Used in: Excavators, loaders, forklifts, generators, trucks, and construction machinery powered by Komatsu or Cummins engines.

🔁 Cross-reference / Part Numbers:

6731-21-1010, 6731211010, 3903920, 390392000, 3928800, 3802150

🛠 Specifications:

Manufacturer: OEM / Komatsu-Cummins supplier

Type: Long block (complete engine assembly with head)

Material: High-strength cast iron block and head

Engine type: 4D102 / 4BT / QSB3.9

Condition: New / Replacement assembly

Packaging: Standard export wooden case

Warranty: Manufacturer’s limited warranty

⭐️ Key Features:

• Genuine OEM-quality long block for Komatsu and Cummins engines

• Fully assembled, ready to install

• Includes cylinder head, camshaft, and valve system

• Precision-built for optimal performance and fuel efficiency

• Excellent durability and heat resistance for heavy-duty operation