Jalopnik Here's Why Harley-Davidson's Knucklehead Engine Is So Valuable
Harley-Davidson's Knucklehead engine released back in 1936, and despite its age, models with the engine can sell for over $200,000 even today.
Harley-Davidson's Knucklehead engine released back in 1936, and despite its age, models with the engine can sell for over $200,000 even today.