An exhaust diameter is 1.02 cm. This is calculated as follows. A 1.8-liter engine is equal to 1,800 cubic centimeters (cc), so a single cylinder's displacement will be 1.8 liter / 4 = 450 cc. You can find the exhaust diameter from the formula:
D = √(6,500 × 450 × 3.14159) / 88,200
The resulting exhaust diameter is 1.02 cm. Read more