Jay Leno has a deep respect for the Merlin V12 engine and owns two cars powered by them. Rolls-Royce developed and built the engine and a variety of companies like Packard licensed and built their own variants. The V12 engine had a displacement of 1,650 ci or 27.0 L and were used in a wide variety of aircraft and even found themselves in tanks and boats. Listen as Jay talks about one of this favorite engines.
Source: Jay Leno Garage
There are two very good youtube video documentaries on Merlin engines .
https://www.youtube.com/watch?v=-fo7SmNuUU4
Dear Sir Very interesting in your rolls royce merlin V12. engine seen on you tube. As a matter of interest to you merlin engines were manufactured in the U S A by packards under liecence.