HORSEPOWER,DYNO'S AND PROPS!

A general, non-powerplant specific, discussion on airboat technology, ie., hulls, rigging, polymer, etc..
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Waterthunder
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HORSEPOWER,DYNO'S AND PROPS!

Post by Waterthunder »

I had a customer who has had a ton of people talking smack to him about his motor. So he came up with a slogan that I really like. THE PROOF IS IN THE PROP! I like it so much it stuck Wayne! Lately I have quit posting prop, pitch and gear ratio info and kinda keep what we find out in house! To many copy caters! But I will say the prop is the great wall I prefer to swing more pitch not make more horsepower! I have built motors that made 50,60 and even 80 more HP to only find out they swung less prop then a motor that made lower HP numbers on a dyno! So I'm setting some guide lines for our customers so they know what prop and what pitch they are going to swing! There will be much more info released about this later!


Right now I will post of the last 4 550HP EFI motors some of them we have ran and tuned on the dyno and they all have swung a 79'' to 80'' 4 BLADE R blade set on 2.5 on average 5,500RPM's and they will swing about 5,000 RPM's at the 3rd mark! After all don't we all wanna swing more prop!
Last edited by Waterthunder on Tue Dec 15, 2009 7:54 pm, edited 2 times in total.
THE PROOF IS IN THE PROP!

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Re: HORSEPOWER,DYNO'S AND PROPS!

Post by BigJakesrq »

Waterthunder wrote:I had a customer who has had a ton of people talking smack to him about his motor. So he came up with a slogan that I really like. THE PROOF IS IN THE PROP! I like it so much it stuck Wayne! Lately I have quit posting prop, pitch and gear ratio info and kinda keep what we find out in house! To many copy caters! But I will say the prop is the great wall I prefer to swing more pitch not make more horsepower! I have built motors that made 50,60 and even 80 more HP to only find out they swung less prop then a motor that made lower HP numbers on a dyno! So I'm setting some guide lines for our customers so they know what prop and what pitch they are going to swing! There will be much more info released about this later!


Right now I will post of the last 4 550HP EFI motors we have ran they all have swung a 79'' to 80'' 4 BLADE R blade set on 2.5 on average 5,500RPM's and they will swing about 5,000 RPM's at the 3rd mark! After all don't we all wanna swing more prop!

Doesn't get to much simpler than that..... I love it!

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Re: HORSEPOWER,DYNO'S AND PROPS!

Post by MYDIXIEWRECKED »

I guess I'm close. 3 - 80" R blades set At 3+ @ 5600 rpm... :D Whatever it is I Like it and it works And until Daves customer service gets to the point wher he gives away free upgraded motors! :lol: Momma says what we got will have to do. :D I see no reason for leaving the dark side... :blackeye:
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Re: HORSEPOWER,DYNO'S AND PROPS!

Post by sberryman »

all them cookies will make you FAT :shock: :lol: :lol: :lol: :lol: :lol:
"The frog does not drink up the pond in which he lives." ~Native Proverb~

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Re: HORSEPOWER,DYNO'S AND PROPS!

Post by crowhater »

I have said this for years. The truth machine is the prop every time. Every airboat guy you see any more claims to have a 500+HP motor. I had a guy claiming he made BIG TIME HP on a 16' boat with a 572. You should have heard this guy beating his chest at the ramp to anyone who would listen. I asked him why my 530CI with the same reduction was turning 4 blades pitched at 2 when he was only spinning 3 blades pitched at 2. So many people buy a motor from Billy Bobs race motor shop and they claim all this HP. I am a firm beleiver that it takes a person who understands airboats to build a strong airboat motor. Just because you can build a 600hp BBC for a street car does not mean it will perform worth a crap on an airboat. What good is a peak HP motor if the motor can not get the prop into that HP range? A motor with a flat power curve will out perform a stronger motor with a peak hp curve. I know several guys with 496 motors that do not come close to spinning what a felber 496 spins but they claim the same HP numbers
18x8 Alum, 496 BBC, 2.6 CH4, 4B 82" S-blades

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Re: HORSEPOWER,DYNO'S AND PROPS!

Post by RiseAboveIt »

Please don't think I'm being disrespectful, but I would like to have one of your 550 or 600 hp boats ride with us for a day. Maybe even a 4 seater with 4 people. I'm always interested in comparing boats.

We have some ruff riding around here, but we always have a good time.

Anyone interested?
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Re: HORSEPOWER,DYNO'S AND PROPS!

Post by BigJakesrq »

RiseAboveIt wrote:Please don't think I'm being disrespectful, but I would like to have one of your 550 or 600 hp boats ride with us for a day. Maybe even a 4 seater with 4 people. I'm always interested in comparing boats.

We have some ruff riding around here, but we always have a good time.

Anyone interested?
Maybe if your location was on your profile it might be easier to line something up. jmo

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Re: HORSEPOWER,DYNO'S AND PROPS!

Post by wilemotorsports »

Since the late 60's an 70's we have always run 78 '' props on 540's people always said that prop was to big but if you look on airplanes with 0540's 0470's 0520's or any six cyld for that matter. They alway had this lenght of prop.So let me see hear now I got how much horsepower 500 hp' 600hp' I dam sure A'INT gona go smaller. We have tested props on guages for years and always found that longer is better.I have always had aircraft motors but they cant blow like a car motor like one guy said watch unlimited one time. :mrgreen: :mrgreen: SHIRLEY I AM

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Re: HORSEPOWER,DYNO'S AND PROPS!

Post by Waterthunder »

Everybody knows a longer prop makes more thrust per lb of torque applied. However as always thrust only is not what makes an airboat run! Their are many dynamics with an airboat that must all be considered to build a well balance all around performing boat!
THE PROOF IS IN THE PROP!

"If you copy someone you will only achieve what has already been done."

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Re: HORSEPOWER,DYNO'S AND PROPS!

Post by Deano »

I don't percieve it to be a news flash that a prop tells a more accurate story than the boat ramp (or any other) dyno hp numbers.

This has been pointed out many times here lately. I used to think that was obvious to a passively casual observer. Now I am beging to think that few people understand torque and importance of the width of the torque curve that brother Crow eluded to. :thumbright:

Deano
Last edited by Deano on Tue Dec 15, 2009 10:00 pm, edited 1 time in total.
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Re: HORSEPOWER,DYNO'S AND PROPS!

Post by plumcrazy »

hold on boys theres prop and then theres prop its not only how big it is, its also how fast, the only differance is sound remember the screw dave
its not hp it tq
:wink:
but it does make since to build a motor and tell the guy thats buyin it what to put on it to get the best out of it 8)

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Re: HORSEPOWER,DYNO'S AND PROPS!

Post by Waterthunder »

Rise above I just realized pitch and RPM can also end that type of my boat runs harder then your boat debate also!! If you swing a prop with more pitch and turn it more RPM's and both boats are the same the motor that swings more pitch and RPM will win every time!

There is never one answer for anything. The Caddy guy's tell me it's torque torque torque and torque is all that matters and the racers say HP HP HP HP is what matters.

My ANSWER: saying you want torque only or HP only is like saying you want a peanut butter and jelly sandwich without the peanut butter!

You can't have one without the other! This is proven by the fact you get one number by measuring the other!
Last edited by Waterthunder on Tue Dec 15, 2009 10:06 pm, edited 1 time in total.
THE PROOF IS IN THE PROP!

"If you copy someone you will only achieve what has already been done."

http://waterthunder.com/
321-508-5316

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grant
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Re: HORSEPOWER,DYNO'S AND PROPS!

Post by grant »

Waterthunder wrote:Rise above I just realized pitch and RPM can also end that type of my boat runs harder then your boat debate also!! If you swing a prop with more pitch and turn it more RPM's and both boats are the same the motor that swings more pitch and RPM will win everytime!
You did say the same, so maybe you got this covered..........block the airflow to the prop and you can turn it faster and push much less!!
"Don't Taze me Bro"

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Re: HORSEPOWER,DYNO'S AND PROPS!

Post by Waterthunder »

That's why I had to throw in the SAME boat guide line! Anyway I will post what our motors will swing a specific prop so customers know what they are looking at so they can compare motors when shopping!
THE PROOF IS IN THE PROP!

"If you copy someone you will only achieve what has already been done."

http://waterthunder.com/
321-508-5316

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Re: HORSEPOWER,DYNO'S AND PROPS!

Post by RiseAboveIt »

Maybe I'm missing something. In Bushnell, We don't see many WT motors on boats. I'm just interest. It's no secret I'm happy with my boat. Just like to see one of your boats ride with us. I know what my barge will do and always look at other options. It doesn't have to be a grudge match all the time like these forums seem to be. I like to ride enjoy the new boats.
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Re: HORSEPOWER,DYNO'S AND PROPS!

Post by Waterthunder »

I don't know anybody who rides the Bushnell area so I can't help ya there! However there might be one there on a ride boat soon you never know!
THE PROOF IS IN THE PROP!

"If you copy someone you will only achieve what has already been done."

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Re: HORSEPOWER,DYNO'S AND PROPS!

Post by muffled500hp »

I think it's a big plus providing customers with dyno sheets. It provides everyone with a lot of information about the engine. I can think of five reasons right off the top of my head.

One, it proves to the customer the value of the engine you are selling, no guestimates of how much power and torque you are selling. I see engine shops all the time selling X-horsepower and X-torque and when it gets a propeller bolted on the crank it tells a whole different story.

Two, the dyno sheet will help provide a better idea of which propeller and reduction ratio to use with a particular setup. If you can see a dyno sheet and it tells you the torque range is higher in the rpm's, then you will want to use a higher ratio reduction for better performance.

Three, a dyno puts real stress on an engine during the break-in vs. just running an engine on a stand for 30 minutes. If anything is going to happen to the engine, it's going to happen on the dyno under a severe load.

Four, it makes me feel better about selling an engine and it keeps everyone honest. I know the engine builder didn't just sell me or my customer, an engine that they assembled with some parts they saw in "High Performance Chevy" or "Hot Rod" Magazine and assume that it's making the power. Plus, I've been building boats long enough to know what horsepower and torque it takes to spin a certain size propeller with what reduction ratio. So, I know if or when the dyno sheet is not telling the true tale.

Five, the engines tuned on the dyno will perform better than one that is just assembled and boxed up in a crate. The timing and jetting can be optimized by looking at what the dyno is telling the builder. You know that Dave, look at the time you guys spent on Waynes engine on the dyno and look at the tweeking you were able to do. Waynes engine is a night and day difference from before.

Folks, there is NO magical combination that works for every application! It is possible to find the right combination for you.
Keith ~~

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Custom built engines for airboats, hotrods, mud trucks, buggies, circle track and drag racing!

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Re: HORSEPOWER,DYNO'S AND PROPS!

Post by BigJakesrq »

RiseAboveIt wrote:Maybe I'm missing something. In Bushnell, We don't see many WT motors on boats. I'm just interest. It's no secret I'm happy with my boat. Just like to see one of your boats ride with us. I know what my barge will do and always look at other options. It doesn't have to be a grudge match all the time like these forums seem to be. I like to ride enjoy the new boats.
Where in Bushnell do you ride mostly? Maybe you could take a trip over to kissimmee for the howl at the moon get together their having? I know there should be a few WT motors there for sure. I know HuntingBigun will be there for sure. He's got a FI WT motor turning a 4 blade 79" R I believe. Here is the link if your interested, http://www.southernairboat.com/phpBB3/v ... t+the+moon

I hope you get to find someone with one, they sure are sweet. Then again some people might say I'm just drinking the waterthunder kool-aid, but it sure tastes good 8)
Last edited by BigJakesrq on Wed Dec 16, 2009 12:23 am, edited 1 time in total.

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Re: HORSEPOWER,DYNO'S AND PROPS!

Post by BigJakesrq »

muffled500hp wrote:
Folks, there is NO magical combination that works for every application! It is possible to find the right combination for you.
That right there say's a lot. I wish more people could grasp that concept.

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Re: HORSEPOWER,DYNO'S AND PROPS!

Post by Waterthunder »

I could agree with some of that Keith but I haven't had to warranty a motor yet this year! I did have a motor break a rocker arm after a 140 hours and that would have not showed up on a dyno anyway. So the dyno doesn't do anything for me there. I do know the best thing a dyno would do for me would be in sales and marketing. I always turn to a dyno when a customer has a buddy or someone whispering in their ear and saying "hey that motor doesn't make the power he claims". That is when a dyno is a big help to me. When this happens we put their motor on the dyno and you know what every time we dyno a motor for a customer it makes the numbers is suppose too and most of the time much more!
I will say dyno sheets are good for many things but they will not tell me or a customer how much prop a motor will swing. And since so many times I have had a motor dyno bigger numbers only to swing less prop I don't put to much emphasis on dyno numbers! In the end all I care about and all the customer really cares about is what prop and how hard they can swing it! After all you purchase an airboat motor to swing a prop not for the numbers it puts on a sheet. I think Smokey Yunick said it ''We race at Daytona not on the dyno!'' I will say I do use a dyno often and the one I use does ton's of RnD for many NASCAR teams. But so many times I find, what worked on a dyno just doesn't swing more prop sometimes it may even swing less!

I built a dyno cell at our shop and came so close to buying a dyno but realized a dyno will not help us build a better product for our customers or help me swing more prop! So instead that money went into something that will help me build a better product for our customers and help me find a way to swing more prop. Besides anytime someone wants me to dyno a motor or I have to debunk someone who is bashing me we just load up and go to a dyno. A dyno who the majority of NASCAR teams use products that were tested on it! Even a dyno has a correction formula that can always be manipulated a prop doesn't. I'm running 3 motors on the dyno next month and I will gain some info on all of them but when I'm done my only concern will be what prop and pitch they will swing when their in the boat! And all of the changes I'm making with these motors are to swing more prop. I could care less if they make more bigger or smaller dyno number I just want them to swing more prop! The real proof will always be in the prop!
THE PROOF IS IN THE PROP!

"If you copy someone you will only achieve what has already been done."

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Re: HORSEPOWER,DYNO'S AND PROPS!

Post by Bob Burnside »

Dave, if you are saiding that a dyno sheet on a motor doesn't matter then I guess you are right, all we need to know is what prop. at what degree, at what length and RPM and what ratio your box is. So the engine will turn the same prop. in FL. Tx. N. Dakota, UT. I don't know for sure but if the Dyno # are the same on one of your motors and someone Else's then they will turn the same prop. The motor that is put together with better parts may last longer. Keith I like what you had to said.

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Re: HORSEPOWER,DYNO'S AND PROPS!

Post by CactusJack »

Just my 2c worth :shock:

Would I be wrong saying the real proof is in the thrust achieved? WT touched on it above, that thrust is the wholy grail. You could spend heaps of cash building a 1000 hp motor, then fit the wrong prop and end up with less thrust than a say, 600 hp motor with the perfect prop [for it].

I believe that all the attention to detail, quality parts, knowledge and dynoing is so important and that the dyno will advise you as to which prop is the best for a particular engine.

To me, thrust is the key.... and equally important is thrust to weight ratio. No point building a motor/prop combo that can produce phenominal thrust, if the motor weighs a ton.... that negates the thrust and dictates a really big hull to carry the weight. :cry:

So, to me, every step is important.... building a quality motor that will stay together, dynoing it to know the motors power charactoristics, what size/pitch prop should be perfect for it, but ultimately the maximum THRUST that is finally achieved is the ultimate goal.

I am not knocking anyone or any thing, this just popped into my head while I was reading the post :wink:

Ok, bring on the flames, I'll get my fire proof suit on :lol: :mrgreen:
I was told I was wrong, once (not sure I believe it though)
If you can't blind 'em with brilliance, baffle 'em with BS
Airboat experience so far, limited to having bolted a gyrocopter to a flat bottom punt.... but THAT.... is about to change, bigtime :-)

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Re: HORSEPOWER,DYNO'S AND PROPS!

Post by plumcrazy »

long story short props are dynos, but the sheet is handy for your base line, on choosing a ratio and a prop and there lots of differant props that like this rpm or that , and boxs and belts that scavage certain amounts of hp and tq. and people will allways have a preferance in what they want , and a engine built fo bristol is a whole differant animal than one built for atlanta. :)

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Re: HORSEPOWER,DYNO'S AND PROPS!

Post by Waterthunder »

All I can say is get ready for another revolution! We are working on something that will be released at the Palm Beach airboat show! And it will result in our customers swinging more prop I spoke to Sensenich yesterday and told them they had better get ready to sell a bunch more four blades! I in no way am saying dyno'es are a bad thing I use them allot myself there are many things to be gained by a dyno. I'm just saying it's all in the combination and I'm more concerned about generating more thrust for my customers!
THE PROOF IS IN THE PROP!

"If you copy someone you will only achieve what has already been done."

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Re: HORSEPOWER,DYNO'S AND PROPS!

Post by wilemotorsports »

Seventy Eight is always great :?:

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