Jamies’ trick, and probably Pogeas’ too, was to fit the crank of a 2 litre twinspark to get the extra capacity. I’d hardly call that a bigger motor. Unnoticeably larger internals too while keeping it just about all Alfa. Their genius is the simplicity of their engine mod to get increased engine capacity + turbo + race ecu (+ forged pistons + con rods) = >400bhp. Surely enough. I agree, no need to go with an engine outside the family.
Jamie and Pogea have put bigger engines or engines with bigger internals in a 4C
Stripping a car to use as parts to surround an engine, to me, is just building a custom car.
It is 100% not putting a lambo engine into a 4C
Similar to how Nascar’s only share about 5% in common with the actual street car they are based on