Import Cylinder Block — Buy in Bulk from Supplier in China

The Cylinder Block from Chongqing Sinounion Industries Inc is engineered for GM diesel engines including the 6.5L, 6BT, 6CT, and 3L models. It is cast from high-strength gray iron with a nominal wall thickness of 8 to 12 mm, designed to withstand combustion pressures up to 180 bar. The bore diameter tolerance is held within ±0.03 mm, and the main bearing bore alignment is controlled to 0.05 mm over the full length. These dimensions align with OEM specifications for heavy-duty truck and industrial engine applications.

The material composition follows ASTM A48 Class 30 gray iron standards, with phosphorus content below 0.15% and carbon content between 3.0% and 3.4%. This ensures good machinability and vibration damping, critical for engine durability. Surface finish on cylinder bores is typically honed to a Ra value of 0.4 to 0.6 micrometers. The block includes integrated coolant passages and threaded oil gallery ports, consistent with standard GM engine architecture. No external reinforcement ribs or cast-in inserts are present, as per the original design intent.

This component is primarily purchased by engine rebuilders, aftermarket parts distributors, and OEM subcontractors in North America and Southeast Asia. Orders are typically fulfilled in cartons of 10 units, with foam inserts and moisture barrier wrapping. The supplier accepts FOB Chongqing or CIF port terms. Minimum order quantities are not specified in the listing, but bulk shipments of 100+ units are common. Buyers should confirm casting integrity via X-ray or dye-penetration testing prior to assembly.

Chongqing Sinounion Industries Inc operates from Nanping, Chongqing, with a registered address at 1-14-12, No.1 Asia Pacific Enterprise Valley. The supplier is classified as imported and harbor-tier, indicating verified export compliance and logistics readiness. No company history, employee count, or production capacity is disclosed in the listing. The supplier's focus appears to be on engine components for GM diesel platforms, with no mention of in-house casting or machining capabilities.

The listing confirms no response rate or average response time, suggesting limited buyer communication infrastructure. There is no evidence of third-party certifications such as ISO or SGS being held by the supplier, despite the description mentioning them. The supplier does not list clients, export volumes, or testing facilities. Buyers should treat this as a sourcing intermediary or distributor unless direct verification is obtained.