{"success":true,"version":"v1","request":{"tool":"get_calculator_schema","calculator_id":"engine-displacement"},"result":{"entity_type":"calculator","id":"engine-displacement","calculator_id":"engine-displacement","canonical_url":"https://tttkmbb.com/engineering/engine-displacement","name":"Engine Displacement Calculator","title":"Engine Displacement Calculator – Cubic Centimetres, Litres and Cubic Inches from Bore, Stroke and Cylinders","category":"engineering","category_name":"Engineering & Automotive","tool_name":"calculate_engine_displacement","featured_mcp_tool":false,"description":"Computes engine displacement from bore, stroke and cylinder count (V = π/4 × bore² × stroke × cylinders) in cc, litres and cubic inches, plus the per-cylinder volume and bore/stroke ratio.","use_when":"You know an engine's bore and stroke and need its displacement, or want to check the effect of overboring or a stroker crank.","do_not_use_when":"You need the compression ratio (use compression-ratio) or a rotary/Wankel engine (displacement is defined differently).","inputs":[{"name":"bore_mm","label":"Bore","type":"number","unit":"mm","required":true,"max":1000,"exclusive_min":0,"description":"Cylinder bore diameter in millimetres (inches × 25.4).","example":86},{"name":"stroke_mm","label":"Stroke","type":"number","unit":"mm","required":true,"max":1000,"exclusive_min":0,"description":"Piston stroke in millimetres (inches × 25.4).","example":86},{"name":"cylinders","label":"Cylinders","type":"integer","required":false,"default":4,"min":1,"max":32,"description":"Number of cylinders.","example":4}],"outputs":[{"name":"cylinder_volume_cc","label":"Volume per cylinder","type":"number","unit":"cc","decimals":2,"description":"π/4 × bore² × stroke for one cylinder (swept volume)."},{"name":"displacement_cc","label":"Displacement","type":"number","unit":"cc","decimals":1,"description":"Total swept volume in cubic centimetres."},{"name":"displacement_l","label":"Displacement","type":"number","unit":"L","decimals":3,"description":"Displacement in litres."},{"name":"displacement_cubic_in","label":"Displacement","type":"number","unit":"cu in","decimals":2,"description":"Displacement in cubic inches (1 cu in = 16.387064 cc)."},{"name":"bore_stroke_ratio","label":"Bore/stroke ratio","type":"number","decimals":4,"description":"bore_mm / stroke_mm."},{"name":"engine_geometry","label":"Engine geometry","type":"string","decimals":4,"description":"Oversquare (bore > stroke), square, or undersquare (stroke > bore)."}],"input_schema":{"type":"object","properties":{"bore_mm":{"description":"Cylinder bore diameter in millimetres (inches × 25.4). Unit: mm.","type":"number","maximum":1000,"exclusiveMinimum":0,"examples":[86],"x-unit":"mm"},"stroke_mm":{"description":"Piston stroke in millimetres (inches × 25.4). Unit: mm.","type":"number","maximum":1000,"exclusiveMinimum":0,"examples":[86],"x-unit":"mm"},"cylinders":{"description":"Number of cylinders.","type":"integer","minimum":1,"maximum":32,"default":4,"examples":[4]}},"additionalProperties":false,"required":["bore_mm","stroke_mm"]},"output_schema":{"type":"object","properties":{"cylinder_volume_cc":{"description":"π/4 × bore² × stroke for one cylinder (swept volume). Unit: cc.","type":"number","x-unit":"cc"},"displacement_cc":{"description":"Total swept volume in cubic centimetres. Unit: cc.","type":"number","x-unit":"cc"},"displacement_l":{"description":"Displacement in litres. Unit: L.","type":"number","x-unit":"L"},"displacement_cubic_in":{"description":"Displacement in cubic inches (1 cu in = 16.387064 cc). Unit: cu in.","type":"number","x-unit":"cu in"},"bore_stroke_ratio":{"description":"bore_mm / stroke_mm.","type":"number"},"engine_geometry":{"description":"Oversquare (bore > stroke), square, or undersquare (stroke > bore).","type":"string"}}},"formula":"cylinder_volume_cc = π / 4 × (bore_mm / 10)² × (stroke_mm / 10); displacement_cc = cylinder_volume_cc × cylinders; displacement_l = displacement_cc / 1000; displacement_cubic_in = displacement_cc / 16.387064","sources":[{"name":"Wikipedia – Engine displacement","url":"https://en.wikipedia.org/wiki/Engine_displacement","type":"reference","retrieved_at":"2026-09-24"},{"name":"NIST Special Publication 811 – Guide for the Use of the SI, Appendix B (conversion factors)","url":"https://www.nist.gov/pml/special-publication-811","type":"standard","retrieved_at":"2026-09-24"}],"freshness":{"type":"static","max_age_seconds":null,"note":"Deterministic formula with fixed constants; results never go stale. Inputs supplied by the caller determine the output."},"examples":[{"name":"86 mm × 86 mm, 4 cylinders","inputs":{"bore_mm":86,"stroke_mm":86,"cylinders":4},"expected":{"cylinder_volume_cc":499.56,"displacement_cc":1998.2,"displacement_l":1.998,"displacement_cubic_in":121.94,"bore_stroke_ratio":1,"engine_geometry":"Square (bore = stroke)"},"url":"https://tttkmbb.com/api/v1/calculate/engine-displacement?bore_mm=86&stroke_mm=86&cylinders=4"},{"name":"Chevrolet 350: 4.00 in × 3.48 in, 8 cylinders","inputs":{"bore_mm":101.6,"stroke_mm":88.392,"cylinders":8},"expected":{"displacement_cc":5733,"displacement_l":5.733,"displacement_cubic_in":349.85,"engine_geometry":"Oversquare (bore > stroke)"},"url":"https://tttkmbb.com/api/v1/calculate/engine-displacement?bore_mm=101.6&stroke_mm=88.392&cylinders=8"}],"faq":[{"q":"Why is a '2.0 L' engine not exactly 2000 cc?","a":"Marketing names round the swept volume; the geometric displacement is often a few cc off (1,998 cc here) and tax classes use the exact figure."},{"q":"Does displacement include the combustion chamber?","a":"No. Displacement is the swept volume between top and bottom dead centre only; the chamber volume enters the compression ratio instead."}],"tags":["engine displacement","bore stroke","cc calculator","cubic inches to liters","engine size"],"related":[{"calculator_id":"compression-ratio","reason":"Static compression ratio from the same bore and stroke."},{"calculator_id":"cylinder","reason":"Volume of a cylinder in general."},{"calculator_id":"horsepower-torque-rpm","reason":"Power and torque relation for the engine."}],"links":{"html":"https://tttkmbb.com/engineering/engine-displacement","markdown":"https://tttkmbb.com/engineering/engine-displacement.md","json":"https://tttkmbb.com/engineering/engine-displacement.json","api":"https://tttkmbb.com/api/v1/calculate/engine-displacement","schema":"https://tttkmbb.com/api/v1/calculators/engine-displacement","openapi":"https://tttkmbb.com/openapi.json","mcp":"https://tttkmbb.com/mcp"},"version":"v1","updated_at":"2026-09-24"},"timestamp":"2026-09-24T01:58:40Z","next_actions":[{"tool":"run_calculator","calculator_id":"engine-displacement","reason":"Run Engine Displacement Calculator with the inputs above."}],"links":{"markdown":"https://tttkmbb.com/engineering/engine-displacement.md"}}