Dialing in new boat..

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Dialing in new boat..

Postby GreyGoose » Tue Oct 10, 2017 9:46 pm

Running a 18x8 with a mas 540 carbed, 2.3 to 1 pushing a 4 blade JX series.
Currently Im turning 5400 rpm which according to the dyno sheet is 726.3 CHp and 706.4 Clb-ft. At 4900rpm it shows 676 CHp and 724.5 Clb-ft. My question is, should I put a little more pitch in it to get around 4900 max rpm? Would this shave a little top end speed and gain me a little dry ground push or am I thinking about it wrong?? Thanks in advance.
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Re: Dialing in new boat..

Postby SWAMPHUNTER45 » Tue Oct 10, 2017 9:55 pm

You have to try it every boat responds differently and the JX are new so I personally have not run them. Based on the S blade data, I can tell you that adding pitch increased thrust and I never lost speed. I only gained in every area keeping the engine in it's sweet spot.

If it was my boat, I would set it up to turn 4950 on the trailer and see what that yields for you.

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Re: Dialing in new boat..

Postby southern safaris » Tue Oct 10, 2017 10:39 pm

I second swamps post , i set up a 18x8 gto with a mast 540 2.3 box and converted from carb to fitech efi and when we dialed it in found her sweetspot we ended up right on 4950 but every boat is different for sure and the latest boat i did the jx blades pushed better @ 4600 on a 2.38 box but totally different setup , i think the jx blades like pitch to push good , just from my experience
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Re: Dialing in new boat..

Postby Prototype » Wed Oct 18, 2017 9:33 pm

The Jx is just as dead at 6k with a 268 as in the 4k range! My 2 blade likes 5200 with a 2.68.........because they are unlike any other prop I've used?
Fitting for the snap of holley 4bbl or nos but very timid everywhere else.
If they weren't so wide I'd almost say they were designed for aircraft apps!

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Re: Dialing in new boat..

Postby GreyGoose » Sat Oct 21, 2017 9:46 am

Well I added some pitch and it does seem to have a little (very little) more push but I'm choked down to 4700 max rpm. I'm not sure if I should of went with the 3 blade so I could have both, the pitch and the prop speed. I was originally going to go with the 4 blade NGR and switched to the JX at the last minute, starting to second guess myself now.
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southern safaris
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Re: Dialing in new boat..

Postby southern safaris » Sat Oct 21, 2017 10:46 am

Don't go second guessing yourself just yet , I'm in no way a cheerleader for the jx by any means yet Im used to running the r blades and s blades so I'm relearning the prop cur've myself, and I see it a lot back here with customers boats most think because they can run and extra blade they should but I'm finding its seldom the case, did you try getting it around the 4900-5000 Mark or did you jump straight down to 4700 ? And roughly what degrees are you running
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Re: Dialing in new boat..

Postby kwanjangnihm » Sat Oct 21, 2017 10:55 am

Sensenich lists 2350 & 2450 as a max rpm for the jx. :scratch:
2350 x 2.3 = 5405
2450 x 2.3 = 5635
4 Blade 80” - 82” 600 to 1000+ HP w/ 2.3 & Higher Reduction

What is the blade pitch mark for 4700?

5400 / 2.3 = 2348
4700 / 2.3 = 2043

You may want to remove pitch from the current setting, 1/2 to 1 degree at a time, until you reach a sweet spot. Also verify each blade with a digital angle gauge.

Swamp, Russ or CMB can comment on the hp & torque data. :salute:

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Re: Dialing in new boat..

Postby GreyGoose » Sat Oct 21, 2017 11:16 am

The builder made a couple of adjustments. He started by adding a little pitch and we were able to break free at 3200rpm, in the field next to his shop. He then decreased pitch and tried that, of course it took more rpm to start moving so we went the other way with it again. This time he said he added slightly more pitch than he did the first time and we put it on the trailer. As far as degrees, I'm not really sure. I'm just shy of the number 2 mark on the blades, whatever that equates to. I took the boat out that same day and got it hung up in some sticky mud and was only turning around 4700 at full throttle. Should I be concerned with lugging the engine? I'll make another adjustment and try to get around the 4950 mark but if it performs better where its at now, is it safe to run?
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Re: Dialing in new boat..

Postby Aeon » Sat Oct 21, 2017 11:34 am

I would pull the plugs and see if all 8 are pushing and you are not starving the motor at high rpm. Then check your timing and make sure it's set where Mas wanted it. Then do a quick leak down test.

Im guessing this is a hp problem not a prop problem.
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Re: Dialing in new boat..

Postby GreyGoose » Sat Oct 21, 2017 2:35 pm

The boat runs dry. I went from a 16' with a 383, 2.3:1, 3 blade NGR to a 18'. Same hull just 2' bigger. Deep water cruise & top end are better than the previous set up but dry ground running seems about the same if not a little less. Only going 2' foot bigger and adding 300 plus hp, I was expecting a night and day difference. Just trying to figure out if Im over propped or if the NGR was a better prop for my set up. Hell, maybe Im expecting too much out of it.
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Re: Dialing in new boat..

Postby Prototype » Sun Oct 22, 2017 10:44 pm

kwanjangnihm wrote:Sensenich lists 2350 & 2450 as a max rpm for the jx. :scratch:
2350 x 2.3 = 5405
2450 x 2.3 = 5635
4 Blade 80” - 82” 600 to 1000+ HP w/ 2.3 & Higher Reduction

What is the blade pitch mark for 4700?

5400 / 2.3 = 2348
4700 / 2.3 = 2043

You may want to remove pitch from the current setting, 1/2 to 1 degree at a time, until you reach a sweet spot. Also verify each blade with a digital angle gauge.

Swamp, Russ or CMB can comment on the hp & torque data. :salute:

:thumbleft:


Kwan?

What is your personal experience with this prop?
You've heard this and Heard that accounts and you post numbers for what? Sench numbers that are public on google?

Buy a jx and post all you want to what you find this prop to be? Then please Post why one blade needs another half degree to smooth things out?

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Re: Dialing in new boat..

Postby jeepinocala1111 » Mon Oct 23, 2017 7:40 am

I think you should be running a 2.55 gearbox or higher. I have no idea of that prop so do the right thing and call Sensenich and ask Darrin.

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Re: Dialing in new boat..

Postby SWAMPHUNTER45 » Mon Oct 23, 2017 8:23 am

It is hard to push a big boat dry.

While I have not used the new JX it would be an interesting field observation to put a 4 S-blade set up on your boat and test it's response. The wider S-blade design may push better. Your one of the new JX users so we are watching your progress. You have great dyno numbers and a good gear. A 2.55 would work also but with as much power as what you have and where you report your pitch setting (close 2) your in the desired range. If those marks are the raised references on the prop shank your in a good place.

When you ad pitch and load the engine keeping it's rpm down, generally speaking your biggest concern should be keeping it out of detonation. If your not suffering detonation then you should be ok. With the dyno data you provided you are in the engines power and torque range. I think going 4950rpm is a great place to test. Keep really good fuel in it and make sure the timing is not set to high if your going to load at a lower rpm. I strongly suggest you consult with your engine builder and see what they recommend before you get on it to much. It's a new engine, our engines get 40 hours on them before really pushing them to their limits.

Blackwater has had excellent results with that 540 build so he is a great resource for you.
Southern Safari as well so you have access to their experiences to help guide you also.

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Re: Dialing in new boat..

Postby kwanjangnihm » Mon Oct 23, 2017 11:17 am

Prototype wrote: Kwan? What is your personal experience with this prop?


Proto was not commenting on the j series prop performance, but rather listing the given performance data in black and white, so the forum could have a conversation on the correct prop pitch, engine rpms, etc, to get the OP dialed in on the performance he is wanting.

I have no experience with the new j series blades. I have read SA posts on the j series performance from yourself and fl cracker, and neither of you seemed too impressed.

Waterthunder wrote: Get ready folks the guys at Sensenich have came up with a new blade profile its making more thrust with less surface area. Going to be a game changer.


You've been running the jx's. Have they “changed your game”, or just changed your mind? :scratch:
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Re: Dialing in new boat..

Postby southern safaris » Mon Oct 23, 2017 9:53 pm

Prototype wrote:The Jx is just as dead at 6k with a 268 as in the 4k range! My 2 blade likes 5200 with a 2.68.........because they are unlike any other prop I've used?
Fitting for the snap of holley 4bbl or nos but very timid everywhere else.
If they weren't so wide I'd almost say they were designed for aircraft apps!



Hey prototype can you elaborate on your findings a little more .... I'm interested on the" just as dead at 6k as 4k " part I'm tuning in a new boat right now with a 2 blade jx and been everywhere from 4600-5400 just playing with it kinda want to compare your feelings to mine so to speak, I just didn't follow you I guess on your first post (sorry I'm just a simple minded fella) most have to write real slow for me cause I don't read real fast :thumbleft:
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Re: Dialing in new boat..

Postby kwanjangnihm » Tue Oct 24, 2017 8:00 am

Proto I grabbed a few of your jx posts for reference:

Prototype wrote: It looks like some hard decisions to make on your own? I don't get some post about the s blade though? I'm only pushing low 4oo's with 3 79's S blades on 2 and a fuel burn of 3 an hour at max. I specked out a retro roller sbc with comp cams and brodix and eagle but the dyno numbers don't lie. 423 was it's top. 268 is my choice and maybe thats my flaw with the j with 2 less cylinders on a single!
If your dyno pics are correct you should be able to go 4 82 ngrs around 2 but every boat is needy. They rarely need less. It's only a grand to add a blade if you buy new.
One thing I can add is the J does not torque roll like the S but considering the size of your hull it would take more than a ls3 for you to be worried about torque roll.

Prototype wrote: Ask Patti if they have something that compares to the sensenich s blade. It sounds familiar what your looking for but want to buy local! Can't really argue that fact!
I would suggest the j but it's just freakin weird so far. It has it's rpm range that is like finding a bikini bottom on the beach. Guess who it belongs too! Nope not that heafty load or light load. The S is real predictable smooth through all rpms for a push boat. I'd almost call the j a turbo prop. When it spools, it works great! Until it does it's just a fan. 16 wide by whatever that thing will twist as long as possible with a 2.68

Prototype wrote: I bought the JX complete for the soul reason that it was referred as a light S blade, just what I needed. I have found that the JX is a bit dead vs the S down low? The JX acts like a big block off the line as best as I can describe it. Or maybe a old dirt bike with a power band? When it grabs, it's a kick in the seat but so far it's nothing like the S or NGR or sabers at low end?
I wish I could say it's smooth but anyone that has ridden old dirt bikes will know what I'm saying. When that power band kicks, hang on!
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Re: Dialing in new boat..

Postby SWAMPHUNTER45 » Tue Oct 24, 2017 11:26 am

Reading all this it sounds as if Goose should have went with the "S" blades honestly.

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Re: Dialing in new boat..

Postby Prototype » Fri Nov 03, 2017 7:54 pm

SWAMPHUNTER45 wrote:Reading all this it sounds as if Goose should have went with the "S" blades honestly.


I'm late as normal but Agree!
JX has the snap the S does not. S has the smoothness the JX does not!

It's almost like stall converters of who prefers what? Except the JX drops it's nuts at 6K with a 268

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Re: Dialing in new boat..

Postby GreyGoose » Mon Nov 06, 2017 3:47 pm

Dropped the boat off yesterday and gonna have them put the ngr on it so I can compare the two. Everything I've read says that the jx should be a better ground runner than the ngr. I guess we'll see.
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Re: Dialing in new boat..

Postby SWAMPHUNTER45 » Tue Nov 07, 2017 10:33 am

My bet is it pushes close to the same or slightly less.

It is my belief that the JX was created to give a better push than the R series but require less torque at the lower range than the S series blades.

When you have a big displacement engine like a MAS or a Branch with the correct ratio drive they make the power and the S series blades will really be your best option. I live big inch engine every day and the S blades do the job exceptionally well. You need to try them.

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Re: Dialing in new boat..

Postby Prototype » Wed Nov 08, 2017 11:05 pm

SWAMPHUNTER45 wrote:My bet is it pushes close to the same or slightly less.

It is my belief that the JX was created to give a better push than the R series but require less torque at the lower range than the S series blades.

When you have a big displacement engine like a MAS or a Branch with the correct ratio drive they make the power and the S series blades will really be your best option. I live big inch engine every day and the S blades do the job exceptionally well. You need to try them.



Your almost dead on!
I've found the S to be a dynamite "stout stroker" blade for push and real smooth through all rpms. My four ngrs also "almost"do that but the Ngr's don't wop! The jx got rid of all the ear noise except it's just dead down low. No wop or hiss or ring!
NGR's is a good safe choice but does not have the snap of the jx when it finally grabs air.

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Re: Dialing in new boat..

Postby SWAMPHUNTER45 » Sun Nov 12, 2017 8:00 am

I'm kind of puzzled with this choice of blade on a 18ft X 8ft powered by a 540 MAS

Was the JX selection something you wanted or did someone from Sensenich feel they were your best option ?

When I first heard of the proto type blades being tested was around the time I was buying my S blades and we were debating if we should hold off for the new product.

I did a lot of research on all the brands and options. Patti from Whirlwind offered a wide blade series and gave great information but my hurdle with the Whirlwind was it liked to be spun up at a lot higher rpm than my combination was purpose built for and the only other option would have been a ratio change.
The WaterWalker engineer Andrew was another great resource and the Maximus blades are a beast but again when we were discussing rpm range I was going to need to spin higher than was best for my engines longevity.
When we met with Darrin at Sensenich and discussed the need and options the S blades were a clear best choice. They had data on other boats one which was built to run the quietest possible in which the owner achieved excellent results at a incredibly low rpm far below the recommended low. Without a doubt I got a product that does what it said it would and have no regrets going with the 4 blade S configuration.

Update us on your recent blade swap.

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Re: Dialing in new boat..

Postby Prototype » Sun Nov 12, 2017 4:00 pm

southern safaris wrote:
Prototype wrote:The Jx is just as dead at 6k with a 268 as in the 4k range! My 2 blade likes 5200 with a 2.68.........because they are unlike any other prop I've used?
Fitting for the snap of holley 4bbl or nos but very timid everywhere else.
If they weren't so wide I'd almost say they were designed for aircraft apps!



Hey prototype can you elaborate on your findings a little more .... I'm interested on the" just as dead at 6k as 4k " part I'm tuning in a new boat right now with a 2 blade jx and been everywhere from 4600-5400 just playing with it kinda want to compare your feelings to mine so to speak, I just didn't follow you I guess on your first post (sorry I'm just a simple minded fella) most have to write real slow for me cause I don't read real fast :thumbleft:


Sure,
I've found the JX likes pitch in the mid 20's on mine with a 268! Low 20's it just spins up to burn fuel and not impressive at all. Pitching it to 30, my motor with the jx just can't handle that drag. I would think it has a relationship with torque and all the other crap like boat length and width and load, but I have a unique situation to test it under load and obstacles! I am finding the jump point/snap,,,, in the jx loaded or unloaded which I've never found in the s or ngr's.
Kwan missed my post about the jx having a power band when it grabs air. The good thing is there is only one band/shot to the jx.
Never twisted a s or ngr as high as I've twisted a jx. never had a need too. That's why I state a smooth prop through all ranges or a needy prop through limited ranges.
But it is easy on the ears regardless!!

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Re: Dialing in new boat..

Postby Prototype » Sun Nov 12, 2017 4:28 pm

SWAMPHUNTER45 wrote:I'm kind of puzzled with this choice of blade on a 18ft X 8ft powered by a 540 MAS

Was the JX selection something you wanted or did someone from Sensenich feel they were your best option ?

When I first heard of the proto type blades being tested was around the time I was buying my S blades and we were debating if we should hold off for the new product.

I did a lot of research on all the brands and options. Patti from Whirlwind offered a wide blade series and gave great information but my hurdle with the Whirlwind was it liked to be spun up at a lot higher rpm than my combination was purpose built for and the only other option would have been a ratio change.
The WaterWalker engineer Andrew was another great resource and the Maximus blades are a beast but again when we were discussing rpm range I was going to need to spin higher than was best for my engines longevity.
When we met with Darrin at Sensenich and discussed the need and options the S blades were a clear best choice. They had data on other boats one which was built to run the quietest possible in which the owner achieved excellent results at a incredibly low rpm far below the recommended low. Without a doubt I got a product that does what it said it would and have no regrets going with the 4 blade S configuration.

Update us on your recent blade swap.


That would be a good post! NGR'S VS JX behind a mas 540!

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Re: Dialing in new boat..

Postby GreyGoose » Tue Nov 14, 2017 9:49 pm

SWAMPHUNTER45 wrote:I'm kind of puzzled with this choice of blade on a 18ft X 8ft powered by a 540 MAS

Was the JX selection something you wanted or did someone from Sensenich feel they were your best option ?

When I first heard of the proto type blades being tested was around the time I was buying my S blades and we were debating if we should hold off for the new product.

I did a lot of research on all the brands and options. Patti from Whirlwind offered a wide blade series and gave great information but my hurdle with the Whirlwind was it liked to be spun up at a lot higher rpm than my combination was purpose built for and the only other option would have been a ratio change.
The WaterWalker engineer Andrew was another great resource and the Maximus blades are a beast but again when we were discussing rpm range I was going to need to spin higher than was best for my engines longevity.
When we met with Darrin at Sensenich and discussed the need and options the S blades were a clear best choice. They had data on other boats one which was built to run the quietest possible in which the owner achieved excellent results at a incredibly low rpm far below the recommended low. Without a doubt I got a product that does what it said it would and have no regrets going with the 4 blade S configuration.

Update us on your recent blade swap.

I called Sensenich to tell them what I was having built. The boat builder wanted to go with the 3 blade NGR that I had on the previous boat and I thought I needed an extra blade being that there wasn't much room to add pitch on the old boat and I was jumping up in horsepower quite a bit. Sensenich agreed that I needed to go with the four blade and told me they thought the new JX 4 blade would be a good fit and probably offer more push than the NGR. At the time it was also cheaper. At 19 degrees I could only turn the JX 4700 rpms. Maybe a three blade would have been the better choice. I did try the three blade NGR over the weekend and at the third pitch mark I was turning 5300 rpms. The boat ran good and pushed through a spot I had been hung up in with the jx. I now have a 4 blade NGR on the way. I like the idea of being able to add pitch and lower my cruise rpms for long runs. With the 3 blade there wasn't any room left to do that. Im not knocking the new JX, but I don't think I had the power to get it to the pitch it likes to be at.
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