SouthernAirboat.com   Pictures & Wallpapers   Classifieds   Forum   Weather & Water Data   Store   Calendar   Airboat Directory   Site Support  
 

By accessing or using this Site, you agree to be bound by the terms and conditions as stated in the SouthernAirboat.com Terms of Service

It is currently Fri Sep 19, 2014 7:54 pm

All times are UTC - 5 hours [ DST ]




Post new topic Reply to topic  [ 17 posts ] 
Author Message
 Post subject: 2 blade vs 3 blade prop
PostPosted: Sun May 13, 2012 6:03 pm 
Offline
Southern Airboat Member
User avatar

Joined: Wed Oct 12, 2011 7:39 pm
Posts: 34
Location: Alaska
Hey everybody, this question is not trying to compare prop makers. What I'm trying to decide is whether to use a 2 blade 74" or 3 blade 72" for my 520 recently converted from a 470. I know there are a lot of threads comparing wt, q, ngh, h, r, etc. I'm trying to figure out if the 2 or 3 is going to have better low end push, run dry, top speed etc. on a 17'x7' boat carrying heavy loads with 3/8" UHMW.
So for each brand of prop, using their recommended sizes and styles, how would a 2 and 3 compare?
Thanks


Top
 Profile  
 
PostPosted: Sun May 13, 2012 6:38 pm 
Offline
Site Supporter - II
Site Supporter - II
User avatar

Joined: Mon Oct 17, 2005 9:46 pm
Posts: 2842
Location: SARNO MARSH
The 2 blade q has better low end and the 3 blade h has better top end. I likes the way my 3 blade h jumps out f the hole better than the 2 blade q and the 3 blade h also has way better top end. I have run all different props and I have like the 3 blade h better than them all so I have stuck with the 3 blade h. Now when I have the extra money I want to buy a set of ngh blades to put them in my 3 blade hub.I would like to try the ngh blades before I buy them. The 3 blade h in my opinion the 3 blade h is a real responsive prop, plus it had great top end and doesn't run out of push like other props I has run. I have run this 3 blade on a 220,470 carb and injection and now I have it on a 520 injected, but I did also have it on when my motor had a carb on it. But I didn't like the carb as much as I liked the fuel. Injection so I put my fuel injection system on my 520 and sold the carb. I have run a couple different props on my 520 and I ended up staying with the 3 blade h.

_________________
I WOULD RATHER PADDLE A CANOE THAN OWN A WATERPUMPER


Top
 Profile  
 
PostPosted: Mon May 14, 2012 10:13 am 
Offline
Southern Airboat Member
User avatar

Joined: Sun Mar 18, 2012 3:40 pm
Posts: 215
So you're saying a 2 blade would be better if I wanted more low end?

_________________
13' Aluminum w/ SBC 350 (440hp), 2.38 Stinger Soft Drive, & 2 Blade 76" R Series


Top
 Profile  
 
PostPosted: Mon May 14, 2012 10:17 am 
Offline
Site Supporter - V
Site Supporter - V
User avatar

Joined: Thu Apr 06, 2006 10:10 am
Posts: 8579
Location: avon park
a 2 blade is more efficient in a wide blade and a third less money 8)

_________________
Vice President WaterWalker Props Inc.
863 676 PROP
davidmosser@airboatprops.com
THE POWER IS IN THE PUSH


Top
 Profile  
 
PostPosted: Mon May 14, 2012 11:26 am 
Offline
Southern Airboat Member
User avatar

Joined: Wed Mar 28, 2007 9:09 pm
Posts: 752
Location: Davie
My caddy dd boat hauls loads of people. The 3 blade h flat out out preformed any 2 blade I've tried from push to top end. My boat won't run dry with any. Lol but it will haul, get on plane and more top end better with the 72" h. That's my experience.


Top
 Profile  
 
PostPosted: Mon May 14, 2012 3:53 pm 
Offline
Site Supporter - VIII
Site Supporter - VIII
User avatar

Joined: Thu Feb 15, 2007 4:01 pm
Posts: 580
Location: Durant/Plant city
Just as important as the number of blades is prop diameter, how big of a prop can you get in your cage and still have 2" of clearance around the prop?

_________________
13/6 LAZER 0520 3 blade Sensenich "NGH"
darrin@sensenich.com
http://www.sensenich.com/
http://www.facebook.com/sensenich.composite
http://www.sensenich.com/contact/find_dealership
(813)752-3711


Top
 Profile  
 
PostPosted: Mon May 14, 2012 8:16 pm 
Offline
Southern Airboat Member
User avatar

Joined: Wed Oct 12, 2011 7:39 pm
Posts: 34
Location: Alaska
74" would be max for my set up.


Top
 Profile  
 
PostPosted: Mon May 14, 2012 8:29 pm 
Offline
Site Supporter - II
Site Supporter - II
User avatar

Joined: Wed Aug 22, 2007 10:31 pm
Posts: 8472
Location: cocoa
JUST BECAUSE U HAVE A 3 BLD DOESENT MEAN IT WILL OUT PERFORM THE 2 BLD IVE HAD 2 AND 3 BLD PROPS IT ALL IN WHAT U WANT IT TO DO AND WHAT U CAN TURN PEOPLE PREACH ABOUT THE H I LIKED IT BUT I WOULDENT GIVE 100.00 FOR A NEW ONE THEY ARE LOUD AS HELL AND DEAD ON THE LOW END IF U ASK ME .. THEY ARE A TOPEND PROP ... + JMO THEY ARE THE FLATTEST BLDS OUT THEIR ANY WEAK MOTOR CAN TURN EM ..FROM WHAT IVE TRYED THE2-BLD Q IS THE BEST FOR PUSH THE 3-H BEST FOR TOPEND AND THE WIDE WHISPER TIP 2 BLD HAD EM BEAT ALL AROUND ... IF U WANNA GO FAST GET A WARP DRIVE .. PUSH Q- WT JMO THEIRS ALOT OF TALK ON THE FUNNY LOOKIN PROP THAT NGH :lol: GOOD TALK THOUGH

_________________
https://www.facebook.com/creativeconcretellc
possible another in the works but for now im airboatless lol


Top
 Profile  
 
PostPosted: Mon May 14, 2012 8:38 pm 
Offline
Site Supporter - VI
Site Supporter - VI
User avatar

Joined: Tue Sep 09, 2008 3:54 pm
Posts: 304
Location: San Diego, CA
Fastcatak wrote:
Hey everybody, this question is not trying to compare prop makers. What I'm trying to decide is whether to use a 2 blade 74" or 3 blade 72" for my 520 recently converted from a 470. I know there are a lot of threads comparing wt, q, ngh, h, r, etc. I'm trying to figure out if the 2 or 3 is going to have better low end push, run dry, top speed etc. on a 17'x7' boat carrying heavy loads with 3/8" UHMW.
So for each brand of prop, using their recommended sizes and styles, how would a 2 and 3 compare?
Thanks



This is a good question. Generally speaking, it is more efficient to move a larger column of air slower that to move a smaller column of air fast. There are less viscous losses and lower form drag with slowing air velocity. What this means to you is that the larger diameter 2-blade should deliver more thrust, all other things being equal. The smaller diameter 3 blade can be quieter because the blade tip speeds are slower.

When comparing a 2 blade to a 3 blade, it should be the same blade style and size (width, diameter, etc) otherwise you would be comparing apples to oranges. Ultimately, it boils down to getting the propeller that will have the optimum blade angle for your engine's power. The hp and operating RPM of your engine will dictate the propeller sizing options, including diameter, blade width, and number of blades for best performance. Other factors to consider are cage clearance, price, aesthetics, response and handling (i.e. personal preference).

A 520 that is putting out 285+ hp, could chose between the 2-blade 74" Whisper Tip standard and the 3-blade 72" Whisper Tip Narrow. Either propeller would be a great match for optimum performance.

Best to you.

Sincerely,
-Patti
:proud:

_________________
WhirlWind Propellers
"Leaders in Propeller Performance Technology"
619-562-3725 wwpc@whirlwindpropellers.com
http://www.whirlwindpropellers.com
http://www.facebook.com/whirlwindpropellers
Dealer Network: http://www.whirlwindpropellers.com/airboat/dealers.html


Top
 Profile  
 
PostPosted: Mon May 14, 2012 8:40 pm 
Offline
Site Supporter - I
Site Supporter - I
User avatar

Joined: Fri May 28, 2010 4:28 pm
Posts: 311
Location: Viera/ Canv Groves Fl
I had a three blade 74 inch H and now I have a 72 ngh it performs similar but the ngh has more down low push but still the same top end push. But the ngh is much quiter. My boat jumps on a plane with the ngh.

_________________
2008 13'6X7'9 Alumitech powered by a Continental 520 and pushed by a 72" Sensenich 3 blade NGH.


Top
 Profile  
 
PostPosted: Mon May 14, 2012 9:57 pm 
Offline
Southern Airboat Member
User avatar

Joined: Wed Oct 12, 2011 7:39 pm
Posts: 34
Location: Alaska
Thanks for all the input. It seems that most are saying a 2 blade 74" would have more "low end push".
If that means to get moving with a heavy loaded boat or possibly off of a gravel bar then that's what I'm after. Not so much after the top speed.
Patti, Im not trying to compare apples to oranges. Just trying to determine how the two props you recommend would perform differently.
"A 520 that is putting out 285+ hp, could chose between the 2-blade 74" Whisper Tip standard and the 3-blade 72" Whisper Tip Narrow. Either propeller would be a great match for optimum performance. "

If they are so close that the performance difference is not noticeable by seat of the pants then I guess the price difference would be the deciding factor for me.


Top
 Profile  
 
PostPosted: Tue May 22, 2012 9:39 pm 
Offline
Site Supporter - II
Site Supporter - II
User avatar

Joined: Mon Oct 17, 2005 9:46 pm
Posts: 2842
Location: SARNO MARSH
JAMES wrote:
JUST BECAUSE U HAVE A 3 BLD DOESENT MEAN IT WILL OUT PERFORM THE 2 BLD IVE HAD 2 AND 3 BLD PROPS IT ALL IN WHAT U WANT IT TO DO AND WHAT U CAN TURN PEOPLE PREACH ABOUT THE H I LIKED IT BUT I WOULDENT GIVE 100.00 FOR A NEW ONE THEY ARE LOUD AS HELL AND DEAD ON THE LOW END IF U ASK ME .. THEY ARE A TOPEND PROP ... + JMO THEY ARE THE FLATTEST BLDS OUT THEIR ANY WEAK MOTOR CAN TURN EM ..FROM WHAT IVE TRYED THE2-BLD Q IS THE BEST FOR PUSH THE 3-H BEST FOR TOPEND AND THE WIDE WHISPER TIP 2 BLD HAD EM BEAT ALL AROUND ... IF U WANNA GO FAST GET A WARP DRIVE .. PUSH Q- WT JMO THEIRS ALOT OF TALK ON THE FUNNY LOOKIN PROP THAT NGH :lol: GOOD TALK THOUGH

I have run the q and the wisper tip. I couldn't wait to get my 3 blade h back.I don't know why your motor wouldn't turn your 3 blade, all 3 of my motors I have had my 3 blade h on had no problems with snap or low end with the prop. I am also calling like I have seen it, I have let many people try my 3 blade h and all of them went out and bought one. When they were running my prop I was running there 2 blades and warp drives.I personaly like the 3 blade h. It is the best all around prop.I like the top end out of it for the low rpm crusie on the water and also like the top end for running on the hill where I spend most of the time I am up the river.I will be trying out the ngh blade in my hub. But I wouldn't ever go back to a 2 blade prop. I like how with the 3 blade on the hill loaded down all I have to do is feather the throttle and it goes. With the 2 blades in the same situations I had to stay in the gas. That is a no brainer. But everyone doesn't run with 3 adults 4dog and a couple hogs and run the hill like we do. Its not just me who thinks the same about the 3 blade h. The man who bought my old laser boat ended up getting ride of the 2 blade for the 3 bladeh

_________________
I WOULD RATHER PADDLE A CANOE THAN OWN A WATERPUMPER


Top
 Profile  
 
PostPosted: Wed May 23, 2012 7:08 am 
Offline
Southern Airboat Member

Joined: Thu Dec 08, 2011 8:32 am
Posts: 244
Good question for all you Boys... I have a fresh O380-190hp, on a 12' Scorpion, with a 68"Q. Trust me I'm Free. I love the low end push, don't need top end. Would a 3 blade, help me, any more at low end ??

_________________
Little Bear 12' Scorpion w / O-360 200hp


Top
 Profile  
 
PostPosted: Wed May 23, 2012 7:28 am 
Offline
Site Supporter - IV
Site Supporter - IV
User avatar

Joined: Sat Jun 27, 2009 8:01 am
Posts: 1764
Location: cocoa / canaveral groves
like patti said depending on the h.p. and blade type your gonna want 1. length 2. pitch so depending on your h.p.rating and getting the blade some pitch probably the 2 bld because it will let you get extra length and pitch more so than the 3 bld

_________________
Air-RobertsImage
experimenting with old step w/t experimental 384.8 c.i. nos 2.68 rotator, 80" three bld ? R
http://www.bcraceengineering.com
Thanks to dave http://waterthunder.com/
New & Used PROPs
WhirlWind prop dealer


Top
 Profile  
 
PostPosted: Wed May 23, 2012 8:42 am 
Offline
Southern Airboat Member

Joined: Tue Jul 14, 2009 11:56 pm
Posts: 112
Location: FT. Lauderdale, FL
Fastcatak, How many hunters do you have on the boat with that Moose on the bow? That's a lot
of meat to pack back to the river. Do you do guided trips? If I was buying the a prop I would talk
to the manufacture of your choice and have them send you a 2 blade hub and a 3 blade hub and then
3 blades in 72 and 3 blades in 74. Try the combos of 72 2blade vs 74 2blade, which ever one you like best . Then try a 72 3blade vs a 74 3blade. Then put the best 2 blade against the best 3 blade and see what you think works best.
Only then will you know what works best on your application. Then send back what you did not prefer.
If you ended up liking a 2 blade set up then I would keep 1 extra blade as a spare incase you damage 1 you will be
able to be back running in no time since all of the blades are matching sets. I know it is a extra up front cost but you will get refunded when you ship one of the hubs an blades back within 30 days . So the real extra cost ends up being the shipping back price of the undesired blades and hub. JMO


Top
 Profile  
 
PostPosted: Thu May 24, 2012 7:53 pm 
Offline
Southern Airboat Member
User avatar

Joined: Wed Oct 12, 2011 7:39 pm
Posts: 34
Location: Alaska
There's two of us, most of camp, and a moose being hauled out.
That animal was taken on the river so we were fortunate to get the boat within 50'.
Not guiding just trying to put meat in the freezer.

Btw we chose to go with the 74" 2-blade whisper tip. Excited to try it hopefully
In the next couple weeks. Thanks for all the input.


Top
 Profile  
 
PostPosted: Thu May 24, 2012 8:04 pm 
Offline
Site Supporter - II
Site Supporter - II
User avatar

Joined: Mon Oct 17, 2005 9:46 pm
Posts: 2842
Location: SARNO MARSH
190 hp I don't think I would have gone with a 74" prop try a 72" 3 blade h. I have seen on here people say a 220 gpu is nt 220 hp. But motor builder say they r 220hp who knows. I know I had a 3 blade h on my stock 220 on a big heavy boat and it woke up big time. It would go anywhere after igot the 3 blade h loaded down and good low end and great top end. I like the top end more than I wanted low end for crusie rpm and for running the hill.jmo

_________________
I WOULD RATHER PADDLE A CANOE THAN OWN A WATERPUMPER


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 17 posts ] 






All times are UTC - 5 hours [ DST ]


Who is online

Users browsing this forum: getchasumairboats and 2 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB® Forum Software © phpBB Group
 Page and Content Copyright ©2014 • SouthernAirboat.com, Inc. • All Rights Reserved