1969 Mercedes 250CE

Mercedes collaborated with engine building masters, Cosworth Technology Ltd. to help develop the 16 valve cylinder head with mechanical valve lifters. They came up with 185 hp from only 2.3 liters displacement which may not sound like a lot (compared to today's engines) but don't forget this was 1983 (almost 20 years ago) and the car was lightweight compared to today's heavy weights.