The Merlin engine was one the workhorses of World War II-era planes. In the GJ 400, Leno believes the V12 is making around 650-700 horsepower. Although, he admits that it could probably be pushed to over 1,000 if someone wanted to. However, he clearly loves this behemoth just the way it is.
While the design is classic, the mechanicals are relatively modern. The engine is fuel injected, and power routes through an automatic transmission to the rear wheels. Many of the updated pieces are hidden as well. For example, what looks like a blower at the front actually disguises an oil cooler.
This is a hard beast not to love, and it puts a big smile on Jay's face. Scroll down to see if it inspires the same reaction in you.