Sourcing engine cylinder blocks from China

Duty depends on the engine application

Read from the UK Trade Tariff on 30 September 2026, heading 8409 covers parts suitable for use solely or principally with the engines of heading 8407 or 8408. For cylinder blocks, distinguish spark-ignition, diesel and aircraft applications. The table includes aircraft categories separately; they are not alternatives for automotive blocks.

Ordinary petrol and diesel blocks generally use the residual lines carrying 2% duty from China. Aircraft engine parts carry 0%. The supplied tariff record shows no anti-dumping or countervailing duty and no attached import controls on these selected lines. The residual lines contain suspensions for specifically described other components; the record does not establish a cylinder-block suspension.

Confirm the commodity code against the engine application, drawing and condition supplied. Describe whether the shipment contains bare castings, machined blocks or assemblies. Related components and the wider heading are covered in the engine cylinder heads guide.

Specify the block and its machining condition

Buy against the engine family, original equipment part number and drawing revision. Specify cast iron or aluminium alloy, heat treatment, liner arrangement and whether the block is supplied as a casting or finish-machined. List the main bearing caps, plugs and other components included, and agree whether any final boring or honing remains for your workshop.

Put bore diameter, roundness, taper, bore spacing, deck height, deck flatness, main bearing alignment and sealing-face finish on the drawing. Agree a pressure-test method for coolant and oil passages, cleanliness criteria and batch identification. Ask for a first-article dimensional report before approving production.

For blocks supplied as consumer replacement products in the UK, the importer is responsible for ensuring consumer safety and meeting applicable labelling requirements. Keep the fitment information and inspection records with the batch. Use your own branding unless authorised to use another manufacturer's trademark.

Worked duty example

Illustrative example, not a quote: Illustrative batch of machined diesel engine cylinder blocks under 8409 99 00 90, invoiced at £8,000 free on board, with £1,200 of freight and insurance to the UK. The customs value is £9,200. Duty at 2% is £184. Import VAT at 20% is charged on the customs value plus duty, £9,384, so it is £1,876.80. Import taxes total £2,060.80; a VAT-registered importer can usually reclaim the VAT, so the lasting cost is the £184 of duty. The import duty and VAT guide explains each step.

Inspection checklist

Identity and material: match the part number, drawing revision, casting marks and foundry certificate to the ordered engine variant; check the included caps and plugs.

Geometry: measure bores, deck height and flatness, main bearing alignment and mounting positions against the drawing; verify the intended liner fit and machining allowance.

Casting and cleanliness: review pressure-test or radiographic results, inspect for cracks and porosity, and check accessible coolant and oil passages for sand, swarf and burrs.

Arrival and packing: check corrosion protection, bore covers, deck-face protection, transit damage and batch identification. Solid wood pallets or crates used for imports into Great Britain must meet the international phytosanitary wood-packaging standard. Record findings using the quality inspection guide.

What goes wrong

A block can resemble the reference sample but have different oil passages, mounting bosses or deck geometry. Porosity can cause leaks, misaligned main bearing bores can prevent correct assembly, and retained casting sand can contaminate the rebuilt engine. Approve the exact variant through dimensional checks, leak testing and sample assembly.

Do not accept a generic test report as evidence for the delivered casting batch. Separate damaged or suspect blocks on arrival and retain their batch identities while the supplier investigates. Agree the permitted repair methods before ordering, including whether welded repairs or plugged casting defects are acceptable.

Cambridge China Bridge sources these products for UK businesses, checking the factory and the documents before shipment. See factory verification. For machinery and equipment, see machinery imports.