Fish Nautique Prop question

Just got my new engine installed in my fish...(big $$$ )

Any chance someone could tell me how far off my prop is going to be? I currently have a three blade, which I a$$ume to be original, but I just went from a tired 351W factory rated at 230-240hp to a brand new 350 rated at 320hp. The boat would previously only turn the 351 up to 3900(ish)RPM.    How far off am I gonna be? I know it's a broad/open ended question, but if someone could just point in the right direction (new prop, if so which one? Repitch what I have, if so how do I decide what to go with? Etc). I would like to be able to cruise around 30 at a fair level of fuel consumption (more reserve offshore, the better, but the quicker I get out there...the better).

Thanks,
Ryan

You could speculate all day long but I would put the original prop back on and see what you get. Take you rpm and top speed numbers and then call a prop guy and they can help you select the right prop or make mods to your existing one.

I think if you try to figure out what's going to happen before you sea trial the boat you will be doing something twice.

redneck, patience is not one of my virtues. I'm in a similar repower situation and called Amce about what we should do to my prop and he told me to sit tight until we run it with the old one and go from there. Patience is over-rated.

reidp wrote: the fuel injected higher HP Correct Craft Nautique engines don't come with a higher pitched prop than the carbed engines, did they guys?

Nope, they didnt. Props designed for the new boats with 330 hp work well on the older ones with 240hp.

'7, you definitely have more torque, but it's more a function of at what rpm in terms of what prop you need to turn. If your new engine was a 320 HP diesel, you'd be turning something much larger diameter and/or pitch wise, as a result of the incredible low-end torque. Or even a 300 HP 454 would require more prop. If you built a 320 HP 302 on the other hand, you may have to turn a smaller prop in order to let the engine reach its power band. Anyway, your target should be to reach somewhere around 5000 rpm WOT, or whatever the mfr recommends, but it is definitely a higher rpm than the 45-4600 the original 351 was scheduled to turn, and that 500+/- rpm is your extra 70HP. Bear with me if this is info you're already familiar with.

As far as upgrades go on a new warranted engine, I might limit them to external bolt-ons like an intake. And unfortunately, the bigger and heavier the boat, the less significant the results will be in terms of speed and economy. Good luck with it anyway and have fun and let us know how she runs.       

redneck, your link says 1982 and your Diary page says 1983.

...but it'll go like hell in reverse.

Anyone know what the stock wheel specs are?

Ok, I just took her out for the first time with the new engine and had to pull the throttle back when she spun right up to 5000rpm and was only hitting 32mph.

Thoughts on where to go from here?

Isn't the real question, which prop helps you catch the most fish? BKH

Max RPMs are 4800. I'd rather have a slow holeshot and more speed on the top end (on a smooth day it could get me toward the gulf stream that much quicker).


What's the shaft size on these bad boys?

Thanks for the info Dave. I'm hoping to chat with a prop shop or two tomorrow and I'll let you know what they say just for the posterity of the few of us who have Fish Nautiques.