Whats more important is interior design. ATS, Ferrari 158 and T33 are all 90°, with similar bore-stroke geometry, have all twin OHC driven by chain, same direct valve opening, 45° inclined valves, flat crank with 5 main bearings for the counterweighted shaft, dry sump … and so on in many similarities.
Interesting, but as far as I know very little of the internals of th ATS 100 engine, I can say very little about the similarities except they both are twin cam V8s.
The tipo 33.2 engine I would rather say has a gear drive of the cams as only the first leg of the cam drive system is with chain, the rest is with gears up to the cams. This is completely different from the Montreal cam drive which is with chains all the way.
Can you confirm that the ATS engine has the same gear drive arrangement as the Tipo 33.2 ? Actually I have only seen this arrangement on the Alfa Tipo 33.2, but have there been others?