burtonrider11
Petty Officer 2nd Class
- Joined
- Jul 28, 2005
- Messages
- 178
Ill try to keep this brief. Last year we bought our first family boat, 97 Starcraft 2010SS. It came with a 2bbl 5.7Merc. Performance has always been reasonably adequate, but I'd love more. I've already tuned up the motor and feel like I've dialed in the props (2 stainless) to fit. THinking about this, I had always toyed with the notion of swapping to a 4bbl manifold and carb. When I double checked out motor, I realized we have a 12 bolt intake, not an 8, so we have one of the crossover motors. So imagine my disappointment when I realized like a fool that after a year, I don't even have the 235hp I thought I did, I am at around 210. This would explain why it feels like this boat performs to around 95% of what I think it should.....
So, that leads me to my next question. If I upgrade, I feel like it would be pointless to just do carb/intake - I might as well swap the heads and get the Vortec. I have a local parts place that I can get a pair off a 99 Suburban for about $600 for the pair, I would figure $600 for carb and intake, $200 for gaskets, bolts etc. So I am at roughly $1400-1500 to swap all this. I figure I might be able to sell the old parts to offset some of the cost....However, before I do those, what do I need to know?????
Are the heads a direct bolt on? Would the stock cam work with these heads or does that need replacing also? If I were to do all the above, what kind of HP increase am I looking at? I am estimating 50hp, but maybe that's too optimistic for bolt on parts. Would I need to worry about adjusting the timing? I have the TB5, so I am hoping I wouldn't have to mess with that. Would the stock exhaust manifolds bolt direct to the new heads? Is there a specific combustion chamber size I need?
Otherwise, my other thought is to just leave it as is, sell it in a year or two and put the $1500 into my next boat and get it closer to what I want - an open bow 22'-24' boat with above average performance....
I guess I just need to know what I am getting myself into. We boat exclusively in freshwater - Lake Michigan, so I am not opposed to using aluminum heads and intakes - I'd love to shave some weight off too
I love to wrench on things and consider myself fairly mechanically inclined, though by no means a mechanic/machinist. This would easily be my biggest and most involved engine project.
I'd love to get some input on it to see what all is involved before I do anything.
So, that leads me to my next question. If I upgrade, I feel like it would be pointless to just do carb/intake - I might as well swap the heads and get the Vortec. I have a local parts place that I can get a pair off a 99 Suburban for about $600 for the pair, I would figure $600 for carb and intake, $200 for gaskets, bolts etc. So I am at roughly $1400-1500 to swap all this. I figure I might be able to sell the old parts to offset some of the cost....However, before I do those, what do I need to know?????
Are the heads a direct bolt on? Would the stock cam work with these heads or does that need replacing also? If I were to do all the above, what kind of HP increase am I looking at? I am estimating 50hp, but maybe that's too optimistic for bolt on parts. Would I need to worry about adjusting the timing? I have the TB5, so I am hoping I wouldn't have to mess with that. Would the stock exhaust manifolds bolt direct to the new heads? Is there a specific combustion chamber size I need?
Otherwise, my other thought is to just leave it as is, sell it in a year or two and put the $1500 into my next boat and get it closer to what I want - an open bow 22'-24' boat with above average performance....
I guess I just need to know what I am getting myself into. We boat exclusively in freshwater - Lake Michigan, so I am not opposed to using aluminum heads and intakes - I'd love to shave some weight off too
I love to wrench on things and consider myself fairly mechanically inclined, though by no means a mechanic/machinist. This would easily be my biggest and most involved engine project.I'd love to get some input on it to see what all is involved before I do anything.
