While searching around google for the words "4ac tuning" i ended up with sites providing bigger and better camshaft applications.. some how i was led here..
Now i would be proud of this 4AC under my bonnet
check the middle text of the lower camcover..
extract from google
'High-Tech' Engine
... The 'High Tec' V6 - 36v - 4AC Experimental Engine. ... The exciting news from Maserati,
however, is their new twin turbo, double overhead camshaft, six-valve per ...