Dialing in new boat..

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SWAMPHUNTER45
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Re: Dialing in new boat..

Postby SWAMPHUNTER45 » Wed Nov 15, 2017 6:45 am

It sort of makes for more questions.

I prefer to run an extra blade on a gear drive boat rather than run a heavy pitched prop. That said every series of blade is different and some may work with heavy pitch better. That engine is what Blackwater runs and it should be a beast. Jason runs a tour boat and puts his engine to the test daily and has a reputation of having a boat that can drag another out of the mud. Your experiences are very different from what he has reported. Have you consulted with the builder of the engine (MAS) since most airboat engine builders know exactly what their engine will spin at a given drive ratio. Something just does not seem correct.

Jason your the resident MAS 540 expert can you offer some perspective?

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Re: Dialing in new boat..

Postby jeepinocala1111 » Wed Nov 15, 2017 7:11 am

I had a three blade prop on my boat I went to a 4 blade and the difference in push is day and night it pushes harder and cruises effortlessly so I guess it is kind of like putting mud tires on your truck verse regular tires you gain more traction. I will say right at the boat ramp before even getting on plane I could tell I did the right thing. Another thought is when I went into Sensenich Propeller's store I noticed a no brainer advertisement telling you the horse power to blade selection so I will only say some boat builders need to pay attention because your screwing the pooch on prop selection :)

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Re: Dialing in new boat..

Postby GreyGoose » Wed Nov 15, 2017 2:53 pm

SWAMPHUNTER45 wrote:It sort of makes for more questions.

I prefer to run an extra blade on a gear drive boat rather than run a heavy pitched prop. That said every series of blade is different and some may work with heavy pitch better. That engine is what Blackwater runs and it should be a beast. Jason runs a tour boat and puts his engine to the test daily and has a reputation of having a boat that can drag another out of the mud. Your experiences are very different from what he has reported. Have you consulted with the builder of the engine (MAS) since most airboat engine builders know exactly what their engine will spin at a given drive ratio. Something just does not seem correct.

Jason your the resident MAS 540 expert can you offer some perspective?

Is he running the 2.3:1 belt drive? I'd be curious to know what pitch he's running also. MAS has 5500 as the max rpm on my build sheet but advertised this motor as being over 750 hp. At 5500 its making 735.3hp. It doesn't break 750 until 5900 and at 6300 shows 761.4
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SWAMPHUNTER45
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Re: Dialing in new boat..

Postby SWAMPHUNTER45 » Wed Nov 15, 2017 5:03 pm

I think he has a 2.55 gear box so the ratios are close.

Certainly a 2.55 is a bit better than a 2.3 with your dyno data.

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Re: Dialing in new boat..

Postby kwanjangnihm » Wed Nov 15, 2017 7:42 pm

ladyblackwater wrote: I can tell you that if you go with anything over a 2.5 on a boat as big as yours you will definitely be unhappy. The big boats don't like big ratios. With your HP and torque I would go with a 2.5 ratio. I've played with many ratios on the same hull with 3 different motors. My 383 liked the 2.3 with a 3 blade Whisper tip EX. My 496 liked the 2.5 better then the 2.3 running 3 blade Superwide Whisper Tip. My 555 big block likes the 2.5 spinning a 4 blade Superwide Whisper Tip. The 2.6 was a bust with all motors. All these test were done on a 18' X 8' Alumitec Hull. So you know if you went with a 2.6 and a 4 blade Superwide you will be way over propped. Gerald is running a 500+hp Waterthunder with a 2.6 OX box with a 4 blade Whisper Tip EX and his boat is over propped. If you are going to only run up to about 5400 rpm (which is a great idea) my choice would be a 2.5 with a 84" 3 blade Whisper Tip EX.
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Re: Dialing in new boat..

Postby ladyblackwater » Thu Nov 16, 2017 8:31 pm

I'm sorry that I didn't see this eairler, I've been very busy. I don't know much about the JX blades. The only thing I know is what I've heard from people that run them. After reading everything and knowing the little I do about the blade I have to say the JX blades are to much prop in a 4 blade set-up with your 2.3 gear. Now if you had a 2.5 gear I would put money on it the JX blades would be on point. People don't think it's that much of a difference between a 2.3 box and 2.55 box but I can tell you it means the world when you are trying to set your boat up a certain way and with a certain prop. I will say from my experience my big boat (18'X8') loves the 2.5 over any other ratio. Also from my experience I will say you will have a good amount of pitch in the 4 blade NGR but will be the better choice for your set-up. I've played a lot with this set up and found that the MAS 540 with a 2.5 gear and a 4 Blade 84" Superwide Whisper Tip gives the best performance with the motor maxing out at 5000-5200 rpm. The only thing that got better with more RPM was the top end and believe me it wasn't worth that LITTLE extra for what I lost. I look at it as why do I need that 25hp or so more when I get everything I want at lower RPM. I will say I can be cruising at 3000rpm and stab the gas, when that hp and torque come together (about 4200rpm) it throws you back in the seat. I will also put out there that after going from a MAS 540 (it's actually a 555 BB now) carburetor motor to it being EFI I will never go back to a carb again but that's a whole nother subject. If you have ANY questions please feel free to contact me. I'll be happy to share my knowledge with you.
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Re: Dialing in new boat..

Postby SWAMPHUNTER45 » Fri Nov 17, 2017 6:47 am

Great info Jason

I find it interesting to note he reported he had the JX blades spinning at 5400 rpm then added more pitch to almost the 2 mark bringing them down to 4700 rpm. He ran those blades in a good pitch range but was just not getting the push he needed. Sounds based on your testing a ratio closer the 2.55 would be a benefit.

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Re: Dialing in new boat..

Postby ladyblackwater » Fri Nov 17, 2017 5:52 pm

Swamphunter I agree that I think he would be better served with the 2.5 ratio and then keep the 4 blade JX. It makes sense to me that it didn't do good/best when he was turning 5400 because he didn't have enough blade angle/pitch to suit the blade. What is crazy is when he pitched them to only turn 4700 and it didn't perform well. The blade was at a great angle/pitch, the motor rpm was over the point of where the HP and torque cross each other and he was just under 700hp at 4700 rpm. This is leeming me to believe that there isn't something quite right with the boat set-up.
Last edited by ladyblackwater on Fri Nov 17, 2017 8:17 pm, edited 1 time in total.
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Re: Dialing in new boat..

Postby Prototype » Fri Nov 17, 2017 8:02 pm

ladyblackwater wrote:Swamphunter I agree that I think he would be better served with the 2.5 ratio and then keep the 4 blade JX. It makes sense to me that it didn't do good/best when he was turning 5400 because he didn't have enough blade angle/pitch to suit the blade. What is crazy is when he pitched them to only turn 4700 and it didn't perform well. The blade was at a great angle/pitch, the motor rpm was over the point of where the HP andtorque cross each other and he was just under the 700hp at 4700 rpm. This is leeming me to believe that there isn't something quite right with the boat set-up.



The Jx is a whole new prop! I'd like to say beast but can't!
I can say it likes power and it peaks at very limited ranges if your willing to find them. Almost build your motor to it vs the normal reverse way.
First prop I've owned that without serious testing a owner could leave 50 hp behind

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Re: Dialing in new boat..

Postby GreyGoose » Fri Nov 17, 2017 10:32 pm

Prototype wrote:
ladyblackwater wrote:Swamphunter I agree that I think he would be better served with the 2.5 ratio and then keep the 4 blade JX. It makes sense to me that it didn't do good/best when he was turning 5400 because he didn't have enough blade angle/pitch to suit the blade. What is crazy is when he pitched them to only turn 4700 and it didn't perform well. The blade was at a great angle/pitch, the motor rpm was over the point of where the HP andtorque cross each other and he was just under the 700hp at 4700 rpm. This is leeming me to believe that there isn't something quite right with the boat set-up.



The Jx is a whole new prop! I'd like to say beast but can't!
I can say it likes power and it peaks at very limited ranges if your willing to find them. Almost build your motor to it vs the normal reverse way.
First prop I've owned that without serious testing a owner could leave 50 hp behind

I probably should of played with the pitch a little more before I gave up on it. To me, it sounds like you cant go wrong with the S blade and a 2.5 on a BBC. Wish I would of researched that a little more before I ordered the boat.
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Re: Dialing in new boat..

Postby GreyGoose » Fri Nov 17, 2017 10:52 pm

ladyblackwater wrote:Swamphunter I agree that I think he would be better served with the 2.5 ratio and then keep the 4 blade JX. It makes sense to me that it didn't do good/best when he was turning 5400 because he didn't have enough blade angle/pitch to suit the blade. What is crazy is when he pitched them to only turn 4700 and it didn't perform well. The blade was at a great angle/pitch, the motor rpm was over the point of where the HP and torque cross each other and he was just under 700hp at 4700 rpm. This is leeming me to believe that there isn't something quite right with the boat set-up.

Im not sure that the blade was at a great angle/pitch even at 4700. Some are saying it doesn't come alive until after the 20 mark. The boat was fast on the water and had great acceleration/ cruise numbers so I cant say it didn't perform well, it just didn't run dry ground as well as I hoped. After running the NGR, I know there isn't a problem with the way the boat is set up.
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Re: Dialing in new boat..

Postby ladyblackwater » Sat Nov 18, 2017 12:21 am

Yes the 2.5 with the S blades is a great setup. That is basically the same setup I have but I run a Whirlwind instead of a Sensenich. I'm happy to hear it's definitely not a boat set-up issue and just a gear to prop issue. So are you happy with the NGR set-up? It seems that the JX blades are very finicky.
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Re: Dialing in new boat..

Postby GreyGoose » Fri Nov 24, 2017 8:57 am

Update- I got the 4 blade NGR on the boat and it runs great. Max rpm at the 2 mark is around 5200-5300. I definitely think this is a much better prop for my set-up. Runs a lot quieter and seems to push dry ground better. I would've liked to try the JX with the 2.5 but I'm happy with the way the boat runs now.
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