Jan Baker is an amazing engine builder because he has built a V12 from two Ford 302 blocks and three Cleveland heads. The engine has a 4.09″ bore and 3.5″ stroke which produces 552 ci (9.0 L) displacement. Baker also made a custom crankshaft and cam for the engine. He built the engine off the idea that many V12s are two inline-six engine connected by a single crank. This is similar to another engine builder using two LSx V8s to make a V12. The difference being this builder actually has video of his V12 running on a dyno. The engine runs two separate ignitions, coils, oil pumps and with some Holley four-barrel carbs the engine produced 697 horsepower and 576 ft-lb of torque on the dyno. The builder didn’t say which vehicle this engine was going in but the oil pan was notched to clear a Cadillac Eldorado transaxle.
Other engine builds using multiple engines:
Source: Horsepower Monster via BangShift