2 to 4 barrel

[rangerdave4]

Hello, is it possible to change from a 2 to a 4 barrel carb and intake on a mercruiser 485, Motor is very strong.and runs great, i up dated and changed over to a alt and electronic ing. coil, wires and plugs. the carb that came with the boat has been changed to a 2 barell rochester it runs good but all the books show a 2GV rochester, this one all the numbers i have found and read dont match up to the specs,

The boat is a 1982 proline 23 walkaround with a merc.485. i have heard that this motor was also available with a 4 barrel. and that the fuel use would be more efficent

Any thoughts and where could i find the intake manifold?
Thanks for what ever help you can be.

i have got a lot of great ideas from this site and i thank you all !!!

David

 

[rangerdave4]

Re: 2 to 4 barrel

Bump....

Anyone try this or heard of it, is it a good idea?

Thank you ....David

 

[fixb52s]

Re: 2 to 4 barrel

Sure you can put a 4 barrel on it. Under normal conditions, you would be running on 2 barrels until you get on it where the secondaries would kick in.

To get the most out of it, Edelbrock has a nice matched carb and intake setup. The one thing I am not sure of is if the factory used different camshafts between the 2 and 4 barrel engines. I think you might want to research this. Gut feeling tells me they would be the same.​

 

[MikDee]

Re: 2 to 4 barrel

I applaud anyone who wants to go from a 2bbl, to a 4bbl, on an engine! Why not get the best "Bang for the Buck" from your engine, But good luck trying to find a carb & manifold for that 470/485 engine. I think the factory made a few that way, that were 200hp. I would venture a guess that the camshaft was the same, but you really should check it out. These engines are frowned upon by those in the know, because of their particular issues, and the fact that the parts are no longer available, but they were a potent little lightweight package when new, and a lot of guys swear by them, good luck, Mike