{
  "schema_version": "1.0",
  "rubrics": [
    {
      "id": "R1",
      "requirement": "The model shall be a single solid body with an overall bounding box of 131.1 x 108 x 80 mm."
    },
    {
      "id": "R2",
      "requirement": "The model shall use millimetres as its unit system."
    },
    {
      "id": "R3",
      "requirement": "The model shall contain a revolved crankcase feature with a revolved-cut internal crankcase cavity."
    },
    {
      "id": "R4",
      "requirement": "The model shall contain a cylinder barrel extruded 80 mm with R10 corner fillets."
    },
    {
      "id": "R5",
      "requirement": "The model shall contain a through cylinder bore of Ø40."
    },
    {
      "id": "R6",
      "requirement": "The model shall contain 2 mm thick cooling fins arranged in a linear pattern of 4 instances at 6 mm spacing."
    },
    {
      "id": "R7",
      "requirement": "The model shall contain 2 mm lower side fins arranged in a linear pattern of 3 instances at 6 mm spacing."
    },
    {
      "id": "R8",
      "requirement": "The model shall contain four Ø4 head bolt holes in head bolt bosses at the cylinder head flange."
    },
    {
      "id": "R9",
      "requirement": "The model shall contain a revolved exhaust stack and a revolved front housing, each with a bore."
    },
    {
      "id": "R10",
      "requirement": "The model shall contain 5 mm mounting lugs with Ø8 mounting holes mirrored about the part's symmetry plane."
    },
    {
      "id": "R11",
      "requirement": "The model shall contain mirrored 5 mm side tabs, each with a Ø6 hole."
    },
    {
      "id": "R12",
      "requirement": "The model shall contain a 4 mm connecting web and a Ø12 upper boss between the crankcase and the exhaust stack."
    },
    {
      "id": "R13",
      "requirement": "The model shall have the material Plain Carbon Steel assigned, giving a mass of approximately 1.10 kg."
    },
    {
      "id": "R14",
      "requirement": "The model shall carry custom properties PartNo = \"Engine-Cylinder-Block\" and Material = \"Plain Carbon Steel\", plus a Description property."
    },
    {
      "id": "R15",
      "requirement": "The model shall use descriptive feature names in the feature tree, such as \"Crankcase Revolve\" and \"Cylinder Bore Ø40\", rather than default names."
    },
    {
      "id": "R16",
      "requirement": "The model shall contain a configuration named Default."
    }
  ]
}