Re: 2bbl to 4bbl
Has anyone converted a 470 from a 2bbl and put on a 4bbl. Just curious i guess i think its supposed to add another 15 hp and use more fuel im sure.
Hi there,
Merc changed the exhaust manifold and elbow to one with better flow and boosted the 470 (4cyl/170hp) to a 485 (4cyl/185hp). They then put a 4bbl carb on it from 1984 to 1989 with various names, 488, 190, 180 and 3.7LX. 3hp, is it worth it? It would increase you boat speed about 0.5 knots, maybe.
If you want more bang for your buck, just changing the exhaust system would be the way I would go. Leave the standard 2bbl carb on, it has plenty enough airflow for that engine.
Cheers,
Chris............
