Big boat little motor

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Tealboy
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Big boat little motor

Post by Tealboy »

Alright fellas,I need some advice. I have a 17x8 custom aluminum boat with a 383 stroker that has 460hp and 480 ft lbs. with a 2.12 rotator swinging a 78" 3 blade WW stumppuller. Now I know the boat is big and the motor undersized for the boat. But is there any performance Gaines and/or benefits I can get by changing prop and reductions? Or do I just wait for the $$$$ for a big block?
I am pitched at the B 20 mark and am right around 4900-5000 rpm. I am saving for a bigblock but I'm still a year or 2 away from that.
Thanks in advance!
TB

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JAMES
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Re: Big boat little motor

Post by JAMES »

[quote="ladyblackwater"]You could get a 2.3 or a 2.5 gear box now if it's in your budget. You will need a bigger ratio than a 2.12 when you go big block anyway. If you are at 20 on the pitch marks on B you are a little to big on prop size for your motor and gear. The B Mark is for direct drive applications.The C Mark is for gear box applications. You will definitely see a difference by going to a bigger gear ratio. This will allow you to put a little more pitch in your blade. It will also be better served to turn your motor up to about 5400rpm full throttle, if your motor is built to build your power and torque that high. With it being a 383 I'm willing to bet it's built to turn higher rpm's to get the full performance of the motor I was explain that b was for gearbox at least that’s what Patty told me to use A is for direct drive and c this from beltbox Unless I misunderstood her but I believe I have a email even stating that
https://m.facebook.com/321ccc/?ref=bookmarks Wp383 268 rotator 3 bld WT/EX 14.4 perdator

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kwanjangnihm
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Re: Big boat little motor

Post by kwanjangnihm »

Image
He'll cut your throat, baby, stick you in the back, drive off in your Cadillac.
He's more trouble than you think, he'll kill your sugar, leave you in the drink.

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Slidin Gator
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Re: Big boat little motor

Post by Slidin Gator »

Tealboy wrote:Alright fellas,I need some advice. I have a 17x8 custom aluminum boat with a 383 stroker that has 460hp and 480 ft lbs. with a 2.12 rotator swinging a 78" 3 blade WW stumppuller.


I am pitched at the B 20 mark and am right around 4900-5000 rpm.
TB
I think Kwan nailed it with the WW info. Teal, you have 10 degrees either way to play with, but honestly you are tuned in the right neighborhood, just on the run all day no issue, conservative side. You can have that motor spinning over 6000 RPM with your existing prop pitched down to 10 degrees. That prop pushes best off ground at lower pitch and is a good match to what you got right now (other than the big ass boat).

Everything the other guys said about needing more gear and prop (and motor) when you go bigger on motor is correct, but for now you can get everything your present motor has to give by tuning the prop.

Based on the present prop, pitch and gear ratio, you got a motor that is making every bit of the 480 ft-lbs rating! The unknown is where it makes 460 Hp? By my calculator a motor can make 457 Hp at 480 Ft-lbs @ 5,000 RPM or 457 Hp at 400 Ft-lbs & 6,000 RPM. I believe you will find your happy home somewhere in between (5-6K RPM). Try decreasing your pitch, go to 15 degrees first, then try 10, then you can home in on optimum for you.

Back to the subject of grinning ear to ear, you got a motor making big block power in a small block form, the correct equation for sure. To make enough difference to go spend $20+ K on a new motor, gear and prop, you need to plan on going well North of 700 Hp or you will not be satisfied. Just keep me in mind, I call dibs on that scrawny little 383 so call me first when you are ready to sell it please. :D

If we can't make a deal, there are several folks on here that will gladly trade their 454 anchors for what you got :slap:

Enjoy :!:
I still think I-10 is the Mason Dixon line.
2013 Mike Stossel Boats, 13' x 7' deck over, IO-540, 74" NGQ less winglets.

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Slidin Gator
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Re: Big boat little motor

Post by Slidin Gator »

LBW I hear you and agree that more gear etc. would optimize what Teal has. I just think it is not enough to warrant spending money if there is a new motor (etc) in the future. Teal has a bit of tweak room in the prop and that is the first thing I would address. One potential goal is a sweet running small block boat that can run dry light, but also haul a crap load of gear to camp. It is a matter of gear and prop. Like I said, dibs on the motor.

It is ironic that I spend time telling folks to take pitch out while I am adding pitch in, but it's the rainy season and I'm saving fuel...

My advice, Tweak the prop and see what you really have, then figure out the new plan. If new gears are a step in that direction, take it!
I still think I-10 is the Mason Dixon line.
2013 Mike Stossel Boats, 13' x 7' deck over, IO-540, 74" NGQ less winglets.

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