i've seen a documentary of the P-47 Thunderbolt, and a testimony of a pilot who took a couple of rounds in the engine, and was able to make it home.
a VR6 engine is VW's narrow-angle V6 engine fitted into some Golf, (previous-generation) Passat and Corrado models. Because the V angle is very small, the engine has only one head for the 2 banks. This makes it compact enough to fit transversely into these small cars.
because of the single head servicing the 2 banks, you can imagine the design of the intake and exhaust plumbing passages cast into the head.