Will a cosworth engine fit 2001 opel corsa c?

No, a Cosworth engine will not fit a 2001 Opel Corsa C. The Cosworth engine is a high-performance engine designed for use in racing cars, and is significantly larger and more powerful than the engine that comes standard in the Opel Corsa C. Installing a Cosworth engine in an Opel Corsa C would require extensive modifications to the car's frame and drivetrain, which would be prohibitively expensive and complex for most people. Additionally, the Cosworth engine would not be street legal in most countries, as it would exceed emissions standards and other safety regulations.