19ft Cobalt with 351w

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haulnazz15

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Mar 9, 2009
Messages
3,720
Re: 19ft Cobalt with 351w

mid 40's. maybe close to 50 with light fuel, driver only, etc.
 
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haulnazz15

Captain
Joined
Mar 9, 2009
Messages
3,720
Re: 19ft Cobalt with 351w

Sure thing. I am giving you a rough estimate based on my boat because they are VERY similar. The Cobalt has a slightly deeper V, but they will be pretty close in length and weight/engine type. I haven't done a WOT test on my newly rebuilt 351w, so I can't give you accurate info on that. I had the Merc 233HP for the numbers I gave you which is with the 2bbl carb. I now have a 4bbl carb and slightly more efficient exhaust manifolds, but I don't expect to pick up more than 2-3mph at the most on the top end.

Speeds were also taken from the stock pitot-style speedo, but it always seemed to be relatively accurate.
 
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dakine

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Sep 2, 2009
Messages
71
Re: 19ft Cobalt with 351w

Four Winns 225 Horizon.
351w SFi
Volvo SXDP Drive.
F7 props.
50 gallons of fuel and one passenger.

51.6 by gps in 6" ripples and no wind.
You should be faster than that!
 
H

haulnazz15

Captain
Joined
Mar 9, 2009
Messages
3,720
Re: 19ft Cobalt with 351w

dakine said:
Four Winns 225 Horizon.
351w SFi
Volvo SXDP Drive.
F7 props.
50 gallons of fuel and one passenger.

51.6 by gps in 6" ripples and no wind.
You should be faster than that!
Click to expand...

There's a good chance his boat weighs about as much as yours, but he's going to have a different drive ratio (not to mention the lack of duo props) and about 35-40 less HP than you since you have fuel injection and your HP is measured at the prop shaft, not at the crankshaft. :(
 
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