Real Time Thrust Tests with Complete Boats

Dang, wish I could get in on this. I am curious about how my boat performs compared to others. I have a 16X8' fiberglass seminole hull with a wore out 220 gpu and a 70" wood prop. I say that only because I know the cylendars need redoing and there was brass bearing shavings in the oil pan when I changed the oil. However, this I have run wide open with other boaters hauling butt down the river and was easily able to stay with them. I'd love to be able to test it against other boats and involve it in what you are doing
 
BUBBA-HAYS said:
any plans on testing an aircraft boat w/ a gearbox?
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that's what I would like to see ,to compair it to a Carmotor with gearbox,maybe the boat Dan had with the 0470 and stinger on it. it still may not produce the numbers of the high HP CM but I don't think it would be to far off.
 
Supercharged LSA motor from Marine Power. Will she catch a fish?
How is the performance of this motor? Does the 6.2 LSA Suprecharged piece got the grunt the BBC had??

Man, I been waiting a week. No, 2 weeks. No wonder it seems so long. :)
 
The LSA had better thrust numbers than the big block. Sorry for the data delays. Will have some info soon. We also retested the 6.2 thunder motor with a tune up and 2:68 ratio.
 
Roxy7430 said:
The LSA had better thrust numbers than the big block. Sorry for the data delays. Will have some info soon. We also retested the 6.2 thunder motor with a tune up and 2:68 ratio.
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Well, come on with your bad self then. Post em up. LOL
 
Latest Test Results: LSA and 6.2 Thunder

LSA: Supercharged 6.2 rated at 550 HP

Ratio RPM 82" Prop 3000RPM WOT
2:38 5200 3 R 430 1449
2:68 5400 3 R 360 1481
2:68 5400 3 S 340 1447

Other: The boat performance was better with the R blades on the water. Holeshot was better and cruise was slightly better and the R was smoother.

Engine: Absolutely flawless. Brand new engine started with the first touch of the starter button - literally. The installation was extremely simple. There were no instructions with the engine and we had no problems with hooking everything up. This was our first experience with a supercharger and EFI. The engine starts with a momentary touch of the starter button....it will turn over on its own until running and if you accidentally touch the starter button while running it will not engage the starter. The engine spools up almost instantly and the throttle is electronic with no hard linkage. You can't make the engine diesel no matter what you do. It starts exactly the same every time regardless of hot , cold or in-between. Fuel economy seems to be about average but more on that later.


6.2 W/T (Carburated)

Ratio RPM 82" Prop 3000RPM WOT
2:68 5500 3 R 350 1382

Other: Notable difference from SBC. Smoother, no diesel, better fuel economy, the gearbox is MUCH quieter. Overall, the same or better in all areas. In owners opinion a very worthwhile upgrade.


Some other details: Our testing is done per our terms. We are attempting to present data in the fairest way possible but there are a few things you need to know. We do at least 3 pulls for every number posted. We post the highest number every time unless we feel that something is not right. For example the LSA pulled 1546 with the 2:68 / r blades. We felt that that number was suspect possibly due to a slightly loose connection so we didn't post that number as it was the only one that high.

When we first started testing we noticed that the first pull was the strongest. We discovered that the tension was not completely releasing and when we zeroed for the next test. What was happening was we were missing the pretension on the system in the next pull making the number somewhat lower. We now ensure that there is no tension after every pull. We now have much more consistency. We also noticed that engine temp can make a difference and we at times will hit a little higher RPM which translates to a slightly higher thrust number.

I am sharing all this for a couple reasons. I want everyone to understand that we aren't "hiding" anything and I also want you to know that the posted numbers are provided in a consistent manor with the same criteria for every setup/pull. The posted numbers are the best we could get out of every boat with the way the owner had set up his boat.

I will share the results for the LSA to demonstrate the consistency norms:
2:68 R blades 5400RPM

Pull 1: 1456
Pull 2: 1481
Pull 3: 1480
Pull 4: 1546
We posted 1481 as the thrust number. This is very typical except for the 1546 number. We felt that there might have been a slightly loose connection. We never hit that number again in any combination in a total of about 20 pulls. Our decision was to not use that number. Please understand that we will continue to make these subjective calls in the future to most accurately share results.

More testing soon!
 
"LSA: Supercharged 6.2 rated at 550 HP

Ratio RPM 82" Prop 3000RPM WOT
2:38 5200 3 R 430 1449
2:68 5400 3 R 360 1481
2:68 5400 3 S 340 1447"

A lot of info here for sure. Couple questions.
1) Did you make pulls with the 2:38/"R" turning 5400 RPMS's?

2)Did you make any pulls with the 2:68/"R" turning 5200 RPM's?

3) Did you make any pulls with the 2.68/"S" turning 5000/5200 RPM's?

4) Where were you at in pitch at all these pulls and did you set them with a digital angle finder and if so, where on the blade and what were the number?

5) Do you have dyno sheets on both motors and could we see them?

6) Are you able to track the thrust curve of each combo? Can we see?

Thanks. No doubt a lot of work went into this stuff.
 
The WaterThunder motor is 500HP@5,500RPM's. So by these numbers 50 more Horse power and a blower get you 100lb's more of thrust.
 
skinny99 said:
"LSA: Supercharged 6.2 rated at 550 HP

Ratio RPM 82" Prop 3000RPM WOT
2:38 5200 3 R 430 1449
2:68 5400 3 R 360 1481
2:68 5400 3 S 340 1447"

A lot of info here for sure. Couple questions.
1) Did you make pulls with the 2:38/"R" turning 5400 RPMS's?

2)Did you make any pulls with the 2:68/"R" turning 5200 RPM's?

3) Did you make any pulls with the 2.68/"S" turning 5000/5200 RPM's?

4) Where were you at in pitch at all these pulls and did you set them with a digital angle finder and if so, where on the blade and what were the number?

5) Do you have dyno sheets on both motors and could we see them?

6) Are you able to track the thrust curve of each combo? Can we see?

Thanks. No doubt a lot of work went into this stuff.
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1) No. Had a rev limiter that maxed me out at 5200. (took some reprogramming to change that)
2) No. Wasn't as interested in 5200 as I was 5400
3) No. same as # 2 (We also had limited time and it was one or the other) We just couldn't get everything done before it got dark.
4) Pitch is a tricky topic. If you have 5 people look at a particular pitch mark you will get 6 answers! We also found a substantial variation in the pitch marks on each blade for the same prop. I purposely didn't post pitch marks because we didn't feel that we could accurately report the numbers. As I stated in another post there is a SA member that swears that his 3 blade R is pitched over 3, another SA member looked at the same prop and identified it as "maybe 2.5" . I think you get where we are coming from. Generally speaking the W/T engine is at 3 and the LSA is at approx 4 with the R blades as tested. The LSA was on approx the 1 mark with the Superwide.
5) W/T identifies this motor as 500 HP with no dyno sheet. The LSA is identified as 550 HP with no dyno sheet. The difference is that the W/T engine is modified from stock with at least a different camshaft and the LSA is 100% stock internally. The LSA's are randomly dynoed and they do have a representative dyno sheet as I understand it. I have seen the dyno sheet and I think it is on the Marine Power web site.
6) I can graph the thrust curve and save the data in a file. We haven't bothered to do this because the RPM cannot recorded. The thrust curve would be different based on how quickly the operator accelerates.

Hope that answers some of your questions.
 
Skinny, to add to Roxys answers to questions 5 and 6 if we did have dyno sheets and thrust graphs we would certianly share them with everybody. We are working with what we have to work with and hopefully we and everybody else can continue to learn from what we are doing because it is ALOT of work. If anybody wants to have a gearbox and prop changing compitition I think me and Roxy can take you. :lol: :lol:
 
poobought said:
Skinny, to add to Roxys answers to questions 5 and 6 if we did have dyno sheets and thrust graphs we would certianly share them with everybody. We are working with what we have to work with and hopefully we and everybody else can continue to learn from what we are doing because it is ALOT of work. If anybody wants to have a gearbox and prop changing compitition I think me and Roxy can take you. :lol: :lol:
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I very much understand how much work y'all are doing. It is a chore I am sure. I am a racer to the core and have spent a lot of time testing, collecting and evaluating data. I know there are some very general and specific answers out in the work y'all have done.
 
Roxy7430 said:
skinny99 said:
"LSA: Supercharged 6.2 rated at 550 HP

Ratio RPM 82" Prop 3000RPM WOT
2:38 5200 3 R 430 1449
2:68 5400 3 R 360 1481
2:68 5400 3 S 340 1447"

A lot of info here for sure. Couple questions.
1) Did you make pulls with the 2:38/"R" turning 5400 RPMS's?

2)Did you make any pulls with the 2:68/"R" turning 5200 RPM's?

3) Did you make any pulls with the 2.68/"S" turning 5000/5200 RPM's?

4) Where were you at in pitch at all these pulls and did you set them with a digital angle finder and if so, where on the blade and what were the number?

5) Do you have dyno sheets on both motors and could we see them?

6) Are you able to track the thrust curve of each combo? Can we see?

Thanks. No doubt a lot of work went into this stuff.
Click to expand...

1) No. Had a rev limiter that maxed me out at 5200. (took some reprogramming to change that)
2) No. Wasn't as interested in 5200 as I was 5400
3) No. same as # 2 (We also had limited time and it was one or the other) We just couldn't get everything done before it got dark.
4) Pitch is a tricky topic. If you have 5 people look at a particular pitch mark you will get 6 answers! We also found a substantial variation in the pitch marks on each blade for the same prop. I purposely didn't post pitch marks because we didn't feel that we could accurately report the numbers. As I stated in another post there is a SA member that swears that his 3 blade R is pitched over 3, another SA member looked at the same prop and identified it as "maybe 2.5" . I think you get where we are coming from. Generally speaking the W/T engine is at 3 and the LSA is at approx 4 with the R blades as tested. The LSA was on approx the 1 mark with the Superwide.
5) W/T identifies this motor as 500 HP with no dyno sheet. The LSA is identified as 550 HP with no dyno sheet. The difference is that the W/T engine is modified from stock with at least a different camshaft and the LSA is 100% stock internally. The LSA's are randomly dynoed and they do have a representative dyno sheet as I understand it. I have seen the dyno sheet and I think it is on the Marine Power web site.
6) I can graph the thrust curve and save the data in a file. We haven't bothered to do this because the RPM cannot recorded. The thrust curve would be different based on how quickly the operator accelerates.

Hope that answers some of your questions.
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As far as 1,2 and 3 go I understand how much time and effort y'all have went througHh.

#4 I very much agree that the marks are very subjective. It is not a dick measuring contest, really it is just an experiment. Do you not think that a digital measurement of the tip angle of just the "R" blade would be a consistent gauge of pitch. It would help you be able to reproduce your numbers easier I think.

I know what I have measured what 2,2.5 and 3 measure like at the tips of an "R". I won't post cause I don't want a pissing match to insue. However it has been pretty consistant between blades.


#5,6 I am not really looking at an acceleration curve more just a chart of thrust per RPM's. If you wanted to do someting like charting one of the motors from idle to WOT at 200 RPM increments. Then test the combo from 4800 at WOT to 5600 at WOT in 200 RPM increments. That would be some very interesting data, especially if you could overlay it with the torque and horsepower curves.

I may be unrealistic in my wants but I believe that is where the real answers lie. Thanks
 
the best thrust of all the boats y'all have tested so far is boat f...... let me explain myself before y'all call me nuts,
boat f is a 220 ground power, i have a pdf on my computer of a dyno of a fresh new built motor at 2800 rpms this engine makes 185 hp that's it ......boat f has a water walker signature series prop 74 inch, it produce a paltry 740 lbs of thrust not much till you do the math........
740 divided by 185 = 4 pounds of thrust per hp......... now take any boat on this test and do the math.

example; lsa supercharged 550 made 1481 lbs of thrust......
the math ; 1481 divided by 550=2.69lbs of thrust per hp 8) i love math

this is a good thread but it would be cool to see, some variety of props maybe a whirl wind or a water walker that is unless this is a sensenich infomercial and so far the water walker is the only prop in the 4 pound club :wink:
 
Skinny, we know there is lots of things that can be done differently but the fact of it all is we are testing these boats the way we want to run them. Remeber we have only been testing our personel boats set up the way we like to run them. We know there is alot of other things that could be done differently and may be done differently at some point but for know this is what we have. Meant very respectfully.

Plum, your right the ground power did suprise us to. As far as thrust goes the Signature did very well however thrust alone was not good enough because the owner has already took it off the boat and sold it. He is now running 4 Sabers and loves the total package alot more. Its WAY smoother, quiter and the seat of the pants feel is not even compariable. We havent thrust tested it sence the prop change but we will one day but to be honest even if the numbers are lower the owner will not regret changing. As far as tested other props, Sensenich is the only ones that offered a prop to be tested. We would love to test some of the other manufactures props but if we dont have them then its kinnda makes it hard to test them. O yea about the math, the 050 with a Sensenich prop will out perform the ground powered boat with a Water Walker prop by far. Land or water. I know I know it should because its stronger right. But the facts are the 0540 is ''God only knows how old'' and not to mention on a alot heavier hull. So if the Water Walker prop was doing so great the you would think it should even things up a little. Well, I would anyway.
 
this is a good thread but it would be cool to see, some variety of props maybe a whirl wind or a water walker that is unless this is a sensenich infomercial and so far the water walker is the only prop in the 4 pound club :wink:[/quote]


We are open to testing anything that comes our way. We haven't refused any manufacturer's requests - we just haven't had any. The only thing we won't do is fudge results. If we are requested to test something we will and we will post the results. Just because we happen to have a particular brand of prop on most of our boats and have had for years, doesn't make us an infomercial. All the prop manufactures know we are testing and so far the only thing we tested that wasn't owned by one of us prior to testing was the Sensenich super wide ...... tested on my boat only. I contacted Sensenich (they did not contact me) because I was interested in that particular prop. Turns out I liked my existing prop better and posted that opinion.

We have been very open about our testing and have stated and will state again that we are not an infomercial for ANYONE. If we test something we will post the results wether we like them or not. We are running our own equipment and have not been compensated a penny by anyone for anything. We aren't the only people with a thrust tester but we are the only ones I know of posting ALL results. Our objective is to help someone (including ourselves) make a decision about their boat configuration or a major purchase. Purposely posting false information doesn't help anyone and we haven't done it and won't in the future.
 
your right poo cant compare a 0540 to the ground power :lol: but the o540 boat with a 3 blade ngh is making 3.36 pounds per thrust asuming the engine is making 260 hp witch it should, and thats the second best prop in this study so far. but if you take the signature series off boat f and put it on the 540 the and do the math the o540 makes 1040 lb of thrust and becomes a better airboat ,a gain 164 lb of thrust , that means you can bring another good lookin gal an more soda waters 8)
 
Plum you are taking the horsepower numbers from a "dyno sheet" for an engine that has never been tested and trying to prove a prop makes x thrust with it...right? I dont think that is realistic or factual.

Maddog
 
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