CNC Machined Billet Aluminum Engine Block
Custom billet aluminum engine blocks machined from your drawing. Precision cylinder bore machining, oil gallery drilling, complex multi-face geometry. Motorsport and prototype production.
Quote in 24h · MOQ: 1 piece · Worldwide shipping
About Billet Engine Blocks
Billet aluminum engine blocks represent the highest level of custom engine construction. Unlike cast engine blocks, billet blocks are machined from a solid block of aluminum alloy, allowing any geometry to be produced to any specification. They are used in motorsport where weight, precision, and the ability to run non-standard bore sizes and deck heights justify the higher manufacturing cost.
EKINSUN machines custom engine blocks and cylinder heads from aluminum billet. We have the multi-axis capability to machine cylinder bores, main bearing tunnels, oil galleries, coolant passages, head bolt holes, and all external features in a controlled manufacturing sequence that ensures alignment between critical features.
What We Machine
- Cylinder blocks — 1 to 8+ cylinder configurations, custom bore sizes and spacing
- Cylinder heads — combustion chambers, port geometry, valve seat machining
- Intake manifolds — runner geometry, plenum volumes, throttle body flanges
- Engine cases — for motorcycles, karts, and small-displacement motorsport engines
- Prototype engine blocks — for academic research and new engine concept development
Precision Boring
Cylinder bore precision is the most critical operation in engine block machining. We bore cylinders to ±0.005mm tolerance using precision boring heads with dimensional verification by CMM after each bore. Bore roundness and cylindricity are measured and reported with every engine block delivery.
Technical Specifications
| Parameter | Value |
|---|---|
| Material | Aluminum 6061-T6 (standard), 7075-T6 |
| Process | Multi-axis CNC Milling + Precision Boring |
| Bore Tolerance | ±0.005mm |
| Bore Surface Finish | Ra 0.4μm |
| Max Block Size | 600 × 400 × 400mm |
| Cylinder Count | 1–8+ (custom) |
| MOQ | 1 piece |
| Lead Time | 20–35 business days |
| Drawing Formats | STEP, IGES, DXF, Hand Sketch |
| Inspection | CMM dimensional report |
Frequently Asked Questions
Yes. For custom engine blocks, many customers come to us with hand-drawn cross-sections defining bore centers, deck heights, and main tunnel dimensions. Our engineers create the 3D CAD model, send it for your approval, and begin machining once you confirm all dimensions. This is common in the motorsport and racing engine community.
We bore cylinders to ±0.005mm using precision boring heads. This tolerance is sufficient for production ring and piston sets. For tighter tolerances required by specific applications, we achieve ±0.002mm using finish honing after boring.
Yes. Internal drilling for oil galleries and coolant passages is part of our standard engine block machining process. These passages are drilled in the correct sequence and at controlled depths to ensure they intersect correctly. Pressure testing of completed blocks is available on request.
Yes. We work with universities, research institutions, and independent engine developers who need prototype blocks in small quantities (1-3 pieces) to test novel combustion concepts, unusual configurations, or research engine architectures.
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