Engine cylinder blocks in grey cast iron, compacted graphite iron (CGI) and aluminium alloy, with or without cylinder liners · material grade and tensile strength, wall thickness and tolerance, bore pitch, casting process (sand, die casting), leak tightness and impregnation, bore honing accuracy
An engine block (cylinder block) is the main cast structure of a reciprocating engine: it carries the cylinder bores, supports the crankshaft main bearings and contains the coolant jacket and oil passages, cast in grey iron, compacted graphite iron or aluminium alloy, with cast-in or pressed-in liners where the bore material needs them, for passenger-car, commercial-vehicle, off-highway and generator engines. Ask three things first: which material grade and minimum tensile strength the casting must meet; which wall thicknesses, tolerances and casting process the foundry will hold; and how leak tightness and bore geometry are tested before delivery.
Cylinder blocks for petrol and diesel engines — grey iron, compacted graphite iron and aluminium alloy, sand-cast or die-cast, raw castings, machined blocks and block assemblies, including replacement blocks and cylinder liners where they form part of the block. Buyers searching for a cylinder block find the same answers here. Cylinder heads, crankshafts, pistons, complete engines and block-handling equipment are outside this page.
01
SinterCast's paper on highly stressed blocks and heads compares materials at 20 °C: ultimate tensile strength is 450 MPa for compacted graphite iron grade GJV 450, 250 MPa for grey iron GJL 250, 300 MPa for GJL 300 and 275 MPa for aluminium A390.0; elastic modulus is 145, 105, 115 and 80 GPa; rotating-bending fatigue at 20 °C is 210, 110, 125 and 100 MPa; thermal conductivity is 36, 46, 39 and 130 W/m-K; density is 7.1 g/cc for the irons and 2.7 g/cc for aluminium. It gives a CGI block specification of 0–20% nodularity, no flake graphite, more than 90% pearlite and under 0.02% titanium, which yields at least 450 MPa in a 25 mm test bar and satisfies ISO 16112 grade GJV 450. [1]
The same paper tabulates weight results for CGI against grey iron blocks: a 1.6-litre I-4 petrol block from 35.4 kg to 25.0 kg (29.4%), a 4.6-litre V-8 petrol from 72.7 kg to 59.6 kg (18.0%) and a 9.2-litre I-6 diesel from 158 kg to 140 kg (11.4%). It also lists bore distortion improvements of 18–28% for CGI over grey iron in four engines. [1]
For aluminium, US patent 6,921,512 states that AA319 and AA356 are used to cast engine blocks, that castings of these alloys are susceptible to excessive bore wear from pistons and rings, and that such blocks need cylinder liners (cast iron, metal-matrix composite or AA390) or bore plating or coating; iron liners are either cast in as cores or inserted in machined bores. Its comparison castings used AA319 at 6.5% silicon and 3.5% copper and AA356 at 7.0% silicon. In its 20-hour bench wear test a bare AA319 bore showed 0.8–1.3 mm³ wear scar against about 0.1 mm³ with an iron liner. [3]
Editorial calculation: GJV 450's 450 MPa is 450 ÷ 250 = 1.8 times GJL 250 and its 145 GPa modulus is about 145 ÷ 105 ≈ 1.38 times; per unit volume aluminium A390.0 weighs 2.7 ÷ 7.1 ≈ 38% of the irons. [1]
Give the foundry the material standard and grade (for example GJL 250, GJV 450, AA319 or AA356 with temper), the minimum tensile strength and where the test bar or specimen is taken, microstructure limits (nodularity, pearlite, flake graphite), hardness range, liner type if any, and the drawing with critical sections.
02
SinterCast states that passenger-car CGI blocks are produced with a minimum wall thickness of 3.5 mm (−0.5, +1.0), the same as for grey iron, and that cutting a water-jacket wall from 3.5 mm to 3.0 mm may exceed process capability. [1] A 2022 Tupy, Ricardo and SinterCast study reports that minimum walls in cast iron blocks fell from 4.5 mm (+1.5/−1.0) in green sand moulds to a series level of 3.0 mm (±1.0) in enclosed core packages, and set 2.7 mm (±0.8) nominal walls and a 2.0 mm minimum inter-bore wall for a GJV 550 petrol block. The high-pressure die-cast aluminium block it replaced had no internal sand cores, a 4.0 mm minimum wall and weighed 14.05 kg. [2]
Casting route: the same study cast its CGI blocks from core packages in green sand flasks on a standard production line, with a 2.0 mm thick interbore water-jacket core in ceramic sand. [2] The aluminium patent lists die casting, permanent mould, semi-permanent mould, bonded sand, lost foam and precision sand casting as routes for its block alloy, and cites pressure tightness between oil, water and combustion passages as a block alloy requirement. [3]
Leak tightness: a Foundry Management & Technology report describes a die-caster supplying four-cylinder engine blocks that installed a vacuum impregnation system to seal porosity so its castings would meet a 1 cc/min leak standard, sealing one block per cycle. [5] Ask for the test medium, pressure, leak limit and whether impregnation is allowed.
Bore finish: in a 2025 University of Miskolc study, EN-GJL-250 sleeves of 88 mm bore and 192 mm length were honed at 7 or 13 bar honing pressure with 45 or 190 µm grains, and average cylindricity (CYLt) across eight setups ranged from 11.09 to 19.54 µm. The paper gives GJL-250 nominal properties of 250 MPa tensile strength and 210 HB. [4] The Tupy study plateau-honed its CGI blocks to the same specification as the iron inserts of the aluminium donor engine and reports bore wall temperatures around 200 °C with peaks below 230 °C. [2]
03
Suppliers linked to this page list engine cylinder blocks; each card links to the page reviewed.
Listings range from grey iron block castings from a sand foundry to replacement cylinder block assemblies for diesel engines in construction machinery and aluminium block assemblies. Ask each for the material certificate, casting process, leak-test record and machining drawing.
04
This is a functional reference built from the sources cited; it is not one maker's design.
| Feature | Role | Fix in the order |
|---|---|---|
| Cylinder bores and liners | Run the pistons; liners in AA319/AA356 blocks. [3] | Bore, liner type, honing. |
| Main bearing bulkheads | Carry crank loads; 20 mm to 15 mm wall example. [1] | Section, bearing caps. |
| Coolant passages | Water jacket; 2.0 mm interbore core example. [2] | Wall, leak test. |
| Oil galleries | Carry oil; must be pressure tight. [3] | Leak test. |
| Outer walls | 2.7–3.5 mm minimum walls cited. [2] [1] | Tolerance. |
05
An engine block quotation needs values for your engine. The table explains each field, gives published values where a reviewed source states them, and says what to obtain from the supplier.
| Field | What it means and published values | Ask the supplier for |
|---|---|---|
| Number of Cylinders | I-3, I-4, I-6, V-6 and V-8 examples. [2] [1] | Layout. |
| Bore Diameter (mm) | Not stated for blocks; 88 mm honed sleeve example. [4] | Bore and tolerance. |
| Deck Height (mm) | Not stated in reviewed sources. | Drawing value. |
| Main Bearing Journal Diameter (mm) | Not stated in reviewed sources. | Drawing value. |
| Coolant Passage Volume (L) | Not stated in reviewed sources. | Volume. |
| Material Grade | GJL 250/300, GJV 450/550, AA319, AA356. [1] [2] [3] | Grade, certificate. |
| Casting Tolerance (mm) | 3.5 mm (−0.5, +1.0); 2.7 mm (±0.8). [1] [2] | Wall tolerances. |
| Operating Temperature Range (°C) | Bore wall ~200 °C, peak <230 °C in one study. [2] | Design limit. |
| Operating Pressure (MPa) | Not stated in reviewed sources. | Test pressure. |
| Weight (kg) | 14.05 kg aluminium; 25.0–215 kg CGI. [2] [1] | Casting and machined mass. |
| Surface Roughness (µm) | Not stated; cylindricity 11.09–19.54 µm in one honing study. [4] | Ra/Rz, plateau spec. |
| Leak standard | 1 cc/min example. [5] | Medium, pressure, limit. |
06
Paste it into your enquiry below or into an email to a maker, then replace every bracket.
Engine: [layout; cylinders; bore; bore pitch] Material: [grade; tensile minimum; microstructure] Casting: [process; minimum wall; tolerances] Bores: [liner type; honing spec] Tests: [leak medium; pressure; limit; impregnation] Supply: [raw casting or machined; quantity]
These companies list engine cylinder blocks.
Lists a cylinder block casting in HT250 grey iron under its engine block products.
Product scope checked 2026-10-11
Lists diesel and aluminium engine cylinder blocks and block assemblies.
Product scope checked 2026-10-11
Lists cylinder block assemblies and engine block castings for construction machinery engines.
Product scope checked 2026-10-11
Explore company information and manufacturing capabilities, then discuss the scope of your project with a relevant supplier.
SinterCast lists GJV 450 at 450 MPa tensile and 145 GPa modulus, against 250 MPa and 105 GPa for GJL 250. [1]
US patent 6,921,512 states they need iron, metal-matrix or AA390 liners, or bore plating or coating, for wear resistance. [3]
Sources checked 2026-10-11. Sources are two SinterCast-hosted technical papers (one co-written with Tupy and Ricardo), a US patent on block alloys, an open-access honing study from the University of Miskolc and a foundry trade report.
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