Carb upgrade

[robb283]

I have a 1996 bayliner 2050ss with a mercruiser 5.7 motor, alpha 1 drive and rated at 210hp in the owners manual. the manual indicates that the 5.7lx from that year is rated at 250hp and shows no differences other than having a 4bbl carb. Is that all there is to it or does it have different heads, camshaft, etc.? Can I get a resonable gain from switching the manifold and carb? if so what is recommended? I use the boat primarily for skiing and cruising.<br />Thanks for any help you can give.

 

[johnkc]

Re: Carb upgrade

the 210 5.7 was a flat tappet motor

 

[robb283]

Re: Carb upgrade

well, from what I've just read that would account for quite a bit of the difference. Is it worth putting a different manifold and 4bbl carb on or do I need to replace the camshaft and heads too? At that point, am I better off to just buy a replacement motor? Thanks for your help John.<br /><br />Robb

 

[ncwest39]

Re: Carb upgrade

You would gain about 17- 20 HP with an aftermarket manifold and a good 600-650 CFM carb assuming the engine is in good shape.I would not go any bigger on the carb without a larger cam as it is easy to over carb the engine.

 

[robb283]

Re: Carb upgrade

thanks ncwest39,<br />can I add a new cam without having to change the cylinder heads and do you have any recommendations on brands?<br /><br />thanks,<br />Robb

 

[ncwest39]

Re: Carb upgrade

Yes you can change the came without changing the heads.Whenever when you change the cam you want to also change the lifters and timing chain.The choice of cam is up to you depending upon what you want.DO NOT OVER CAM!You will have more problems than you know what to do with.Find a good supplier and tell them what you want performance wise and they should get you the right cam.Other issues are valve springs,valves,compression and general engine condition which if are bad the best cam in the world wont fix.

 

[johnkc]

Re: Carb upgrade

rob,the 250 hp was a 2bbl carb , same as what you have. only diff was the roller cam.what are you trying to obtain? the 2050 runs well with the 210 and gets good fuel ecomomy.i feel that you are almost at the point of diminishing returns with this boat ,you can put a lot of time and money into it and only gain maybe 4-6 mph.

 

[robb283]

Re: Carb upgrade

Thanks guys, I think that answers my questions. I was looking for ways to get more go for skiing and cruising without having to buy a different boat or spend a lot of money on this one. I'll probably just leave it the way it is. Thanks for your time and input.<br />Robb

 

[johnkc]

Re: Carb upgrade

rob, the best you can do with what you have is to make sure you are at the top of your rpm range with your normal load. then the boat will perform well for skiing and cruising.