Simplify the following text for a Grade 6 native English-speaking person.
Original: The YB series of 1993 c engines are based on the older Pinto engine block , and were introduced in the road-going Ford Sierra RS Cosworth in 1986 with 204 P. With 5,000 units built for homologation purposes in Group A , both for rallies and touring cars .
Simplified: The YB series of 2.0 L engines are based on the older Pinto engine block . They were introduced in the road-going Ford Sierra RS Cosworth in 1986 with 201 horsepower .