I think you'll find that the last of the real 'genuine' Alfa Romeo engines was the Arese V6, found in the 156, 166, 916 series GTV and Spider. And what a great engine that was!
Your 2.4 in the 159 is a Fiat block, and given a little extra oomph at 210bhp compared to the slighty more detuned versions found in Fiats and Lancias (on the Continent that is). It has no Alfa Romeo 'ancestry' whatsoever. But at least it's a Fiat Group engine, which is more than can be said of the 1.8, 1.9 and 2.2 JTS petrols, which are all GM engines (the 1.8 MPI in particular being taken directly from a Vauxhall Vectra). The current V6 is a Holden unit built in Australia.
Again the 1750tbi is a Fiat Group engine, although varying states of tune will no doubt be reserved for Alfa Romeo use.
Alfa Romeo will never, ever have it's own unique engines ever again.
Hope that helps.
Last edited by Spider95; 08-12-09 at 17:56.