Back to the main site

Turtle and The Hare

Geewest, since i don't know your boats set up, i have to ask, 2 toon, triple, esp, elliptical, lifting strakes?

Without knowing the set up, my first thought would be adding lifting strakes to get the boat up on plane, with less 'plowing' of the toons since the CG is farther forward with the I/O.
 
Looked at the performance bulletin on the 350 O/B and can understand why my I/O is so much slower. At speed less than two feet of the toon is out of the water and trimming up does not raise much more out of the water before the prop starts cavatating. Also thinking the engine bay puts lot more wetted surface than a full ESP toon. Our max speed with very rough toon bottoms is 36 mph. I propped it for pulling skiers and cruising and realize this boat is not a top speed boat. Sure is fun to drive with the ESP.
 
BulldogsCadillac said:
All I can say is WOW! I just read through that whole build topic, amazing. I was able to read the words, didn't have any idea what you were talking about most of the time, obviously because of my lack of knowledge in all things nautical. From the responses, they seem to understand it all. I must say, I sure have a lot of respect for your knowledge and thoroughness in this project. I can't imagine the cost of it all, but it sure seems like no expense was spared. Well done!

Derrick
Click to expand...
Thanks Derrick, There were ongoing challenges in that project. We were fortunate to access the reputed "Best Of The Best" expertise in the industry. While we may not have subscribed to any one given suggestion, that individual statement was weighted with other expert credential suggestions. The suggestions were then compiled to create a final decision for any given uncertainty/part of the project.

For example, the engines are truly a work of art. Aesthetics are one thing, the parts you don't see is the science. One weak link in any chain causes the chain to be only as strong as the weak link. The potential for creating a weak link is endless. Harmonic vibration/conflicting frequencies will destroy anything known to man. Factors such as crank to rod ratio effect torque/horsepower at given RPM's, plus vibration. Flywheels are available in a range of alloy, hardness and weight. While they may all balance similar, when cold at static position, heat and Harmonic vibration may throw the balance off enough to cause catastopic failure. The list goes on and on and on.

The hull on that boat is said to have had a technician laying under it for over 2,000 hours, before we got the boat. The effort was cutting, grinding, glassing and truing to improve Hydrodynamics and efficiency. That effort worked, but added emphasis to critical CG location in our part. The boat,now, "Loves To Fly". That is a good thing, as long as it flies level, NOT Bow low. Bow low results in a "stuffing" or "submarine". That results in people getting hurt. Well, it flies flat, and that took some math, weighing, locating, even a little SWAG. Fortunately, we got it right the first time....A lot of similar race boats have 50# lead shot bags scattered around the hull to get the CG, Hydrodynamics and Aerodynamics in unison.

Prior to 2008 economy, a top flight Boat Center void was perceived. Therefore, along with a personal recreational mission, a business model was created. The objective was to create a dealership/service center that would draw from coast to coast, border to border. Step one was to study the application as engineers, using our internal resources, not at the customers expense. The effort drew attention from several of our qualified associates. That opportunity is not dead, just not pursued.

Subject to the economy, the model will come to fruition. The complex will be focused on technical stuff others may not embrace. Pontoon Boats are high on that list. Moving forward, Bennington would be approached for the purpose of negotiation.
 
CcanDo,

What a great read and very educational!

About 15 years (or so) ago I had a Talon 25 which we throughly enjoyed for about two years. We had a single supercharged I/O and was able to GPS it at 116 on it's best day. The Talon is kind of a toy when compared to the Motion GT430 but we had fun. Tunnels rock, as you explained CofG is very important on tunnels, hydros, and wings (maybe our toons in the near future).

Keep up the great post, love the material!

Steve
 
Last edited by a moderator:
StevE said:
CcanDo,

What a great read and very educational!

About 15 years (or so) ago I had a Talon 25 which we thoroughly enjoyed for about two years. We had a single supercharged I/O and was able to GPS it at 116 on it's best day. The Talon is kind of a toy when compared to the Motion GT430 but we had fun. Tunnels rock, as you explained CofG is very important on tunnels, hydros, and wings (maybe our tunes in the near future).

Keep up the great post, love the material!

Steve
Click to expand...
Steve,

I have never been in a 25 Talon, but always thought they were a nice boat. You had it dialed in to see 116....How much power did it have ?

There is a something hard to describe about ANY boat that feels like it just wants to be "good". To me, that means it doesn't do anything stupid, little if any porpoise, as it easily goes on plane, runs flat, flies flat and handles good. The rest of it is easy to dial in.

We have a friend from New Orleans that had a 30' Talon with two 1,200 HP engines and 3A drives. The last time we ran together was at a poker run, he lost one engine. He blamed us because he pushed the Talon harder than ever before, trying to keep up with the Motion.

Redundantly, I say again, JMHO, the Bennington/Yamaha 350 package is "best value". The fact, by comparison, it is so user friendly, offers multi-tasking (skiing, tubing, group capable and by comparison, FAST.), and even racing at a logical level. The "New Cruiser" is the most amusing, but close behind is the 100K Ski Boat, the 70..80..90..100K run-a-bout, even other Pontoon Boats. They all seem to perceive any Pontoon Boat is low, slow, plows, doesn't handle...Kind of like tolerating a second class citizen. That is, until they get smoked by the Bennington...Then, generally speaking, they collectively, try to ignore it as though it didn't exist. Perception is, something is wrong with that picture, it only has one outboard engine, runs quiet, looks to handle good, looks like a whale and with the polished tubes, looks longer.

We were at a Marina having lunch, a person at the next table was talking boats with his friend. The Guy said, "I don't think I'm Ready For A Pontoon Boat Yet". His friend said, "I don't know, I haven't seen it, just heard there is one around Ft Worth that might shock you, I heard it's an Outboard Bennington". Point is, "Perception" is an interesting word.

The Talon @ 116 does not allow for many, if any, mistakes. While 116 is a very respectful, triple digit number, perception has it to be fast, but today, is not at the top of the ladder. Comparatively, the Bennington is perceived to be slow, on the low rung, but in it's class, is at the top of the ladder.....So goes shocking.
 
We were powered with the 502cid mercury base engine, this engine was never placed on a dynamometer but an educated estimate from the engine builder was 650 to 670hp. The power was put to the water using a Bravo One (X) outdrive, the weakest part of our build. We did use an external shower head to provide additional cooling to the drive. This boat was actually bought at the Miami boat show, the engine work and blower was added about a year later. The goal was to break 110 with a single engine, I was afraid of twins just in case we blew an outdrive/engine at high speeds, we sold the boat about 6 months after our mission was accomplished. Truthfully I wasn’t comfortable at those speeds in a 25 foot boat. BTW: fastest I’ve ever been on water.

The weird thing for me while learning to drive the tunnel was having to trim down to keep the bow level as the hull lifted, all of my V-hull boats we were very used to trimming the bow up to gain maximum speed and sometimes chine walking on the smaller 18 to 20 footers, very different indeed. I could actually feel the tunnel hull release from the water.

I’m sure you have a more scientific description of what I’m saying.

Steve
 
Steve,

It sounds like you have considerable knowledge/experience. I admire your diplomatic reminder of "Trimming Under" exponential to speed.

One of the interesting parts of a cat is that moment when Aerodynamics overcomes Hydrodynamics. IMHO, the Talon has a good airfoil. The leading edge is a fat cord that produces early lift. And, as speed increases, lift migrates toward the transom.

Some engineer the leading edge of the tunnel with a blunt knife edge. The laminar flow is then somewhat static or in one spot. The wing then stalls until enough relative wind lifts the whole boat. Prior to lift overcoming gravity, the knife edge, leading edge may stall, regain lift, stall again and etc. That culmination produces porpoise.

The same may apply to the pontoon boat. Without a FULL length wave shield, parasitic drag is created by the cross members. Plus, there is a burble of compression. So, subject to speed, stall/lift may effect ride and performance.
 
CcanDo said:
The wing then stalls until enough relative wind lifts the whole boat. Prior to lift overcoming gravity, the knife edge, leading edge may stall, regain lift, stall again and etc. That culmination produces porpoise.
Click to expand...
I never experienced that particular problem. At speed that sounds like a very dangerous situation, especially in 4+ foot seas. I would hate to stab a wave at those speeds. All of our playing was on an inland lake; we never had much more than a few boat rollers to contend with.

Now I've stalled an airplane wing more times than I can count on models and full scale.

Steve
 
CcanDo said:
Plus, there is a burble of compression. So, subject to speed, stall/lift may effect ride and performance.
Click to expand...
Very interesting, I never gave thought to a pontoon boat until now. What is the possibility of lifting the transom from the aft compression to gain speed? This would actually give a twin tube an advantage over a triple tube.... would it not?

While thinking outside the box, why haven't exotic composites been used for logs other than cost? It would be easy to shape them for the best performance, lifting strakes etc. could be formed into the log, they could be lighter and stronger. There would be no corrosion concerns... thinking out loud.

Steve
 
StevE said:
Very interesting, I never gave thought to a pontoon boat until now. What is the possibility of lifting the transom from the aft compression to gain speed? This would actually give a twin tube an advantage over a triple tube.... would it not?

While thinking outside the box, why haven't exotic composites been used for logs other than cost? It would be easy to shape them for the best performance, lifting strakes etc. could be formed into the log, they could be lighter and stronger. There would be no corrosion concerns... thinking out loud.

Steve
Click to expand...
Interesting, I once asked Peter H. about using a pontoon deck on top of his Skater hulls. He responded with, "to much liability". The hull is known to work and adding the deck should make for an easy build. So, the composite build design is basically done, just a matter of compiling the pieces.

The present pontoon isn't fast enough to benefit from airfoil lift. The hull, basically relies on compression or, pilot talk, "ground effect". However, if there is aerodynamic benefit to be had, it may be in leading edge design. The leading edge may be contoured to create a "Zap Flap" The result might then start to work on top as the bottom sees less cubic feet to compress while reducing parasitic drag. The model may then raise the bow enough to significantly reduce whetted surface.

An example of that sensitivity was found when we added the last few feet of wave shield and boxed the outside spray deflectors. Whereas, the transom weight already had the hull taking a "set" when static, it was interesting to see the relative angle being maintained when the boat goes on plane. Speaking of which, the investment in a prop VS: boxing the spray deflector, IMHO, boxing the spray deflectors, wins. Then, the extended wave shield, then the prop, offers most bang for the buck. Not only may speed increase be realized, but improved handling and ride.

BTW, what type of equipment have you flown ?
 
Left seat Cherokee six 300, and the PA-140 which I learned in. Haven't flown left seat in some time, I had a heart attack at 46 years old (11 years ago), can't pass the medical for pilot in command. I take the right seat often with friends and still enjoy flying. I do have a small deposit on a Icon 5 (a sport amphibious aircraft). I have been the airboss for the aerobatic pilots; Patty Wagstaff, Gary Ward and Greg Connell. For those reading and having no knowledge of airshows; those pilots do the aerobatic flying and the airboss works with the FAA to obtain the airshow waiver and then over-see the airspace during the show (and ground operations). The airboss would also be the logistic problem solver and the person that ultimately is the one whose backside is in a sling if the event had an accident.

BTW: All three of those pilots are excellent people, they love what they do, they enjoy sharing it in conversation with anyone, they are very approachable.

I really like flight so I have now begun flying giant model airplanes (gas powered) and turbine powered models. Even fly a float plane from my Bennie lounger :)

Steve
 
Last edited by a moderator:
Lloyd, not that my boat is fast enough to make a difference, what does boxing in the spray deflectors entail? And, i have 3/4 wave shield, and noticed a much smoother ride, are you going full length for water or air drag?
 
Ccan - I have the same question (what is boxing the deflectors and what is the gain?). Also, when driving the boat this weekend, I leaned over the Stbd rail and noticed water coming out above the tube about 3 foot back from bow at 28 mph cruise speed. Looks like the spray from the center tube is being driven over the outside tube. I noticed that the wave shield does stop before the front of the boat. As we can not get the bow up like your toon rides, would finishing the shield off to create a full length tunnel make enough difference to do the work? Any reason not to do it?
 
Last edited by a moderator:
Geoffrey & Brenda said:
Lloyd, not that my boat is fast enough to make a difference, what does boxing in the spray deflectors entail? And, i have 3/4 wave shield, and noticed a much smoother ride, are you going full length for water or air drag?
Click to expand...
The spray deflector Revision is quite simple. Bennington can furnish those simple pieces (4 Pcs. total) and they should be affordable. The new pieces will simply weld under the present deflector....Cost will be less than an hour for the welder. The effect should then cancel "Down Lift", plus as spray hits the deflector, redirect spray away from the hull. (if a drawing is not available otherwise, I would happily fax a sketch)

The full length wave shield may be construed to be similar to sticking your arm/hand out of the automobile window at speed. Turn your hand vertical and parasitic drag/force load occurs, turn your hand parallel to direction of travel and parasitic drag/force load decreases. Or, at some angle, airfoil is introduced and up load/down load occurs. The same goes with partial wave shield/exposed cross members, parasitic drag occurs/force load increases and speed decreases. The term "Wave Shield" may be perceived as preventing water from reaching the cross members. However, because of disrupted laminar flow, the exposed/burbled area may be tested to be low pressure, actually "lifting" water to the exposed crossmembers/deck. Subject to constantly injecting water to the exposed floor, the then wet bow floor gets heavier, effects CG, increases whetted surface and etc.

Note: you may get argumentative resistance for extending the wave shield. The argument may be supported because of restriction to electrical wiring. However, an inspection plate for that area, is a possible rebuttal.
 
Last edited by a moderator:
Remediation said:
Ccan - I have the same question (what is boxing the deflectors and what is the gain?). Also, when driving the boat this weekend, I leaned over the Stbd rail and noticed water coming out above the tube about 3 foot back from bow at 28 mph cruise speed. Looks like the spray from the center tube is being driven over the outside tube. I noticed that the wave shield does stop before the front of the boat. As we can not get the bow up like your toon rides, would finishing the shield off to create a full length tunnel make enough difference to do the work? Any reason not to do it?
Click to expand...
Three feet back from the bow is about where the present wave shield may end. No, I know of no reason you should not fill in that area. Meanwhile, if your plowing enough to cause water to boil over the tube, then the floor may have gotten wet and added weight.

However, as a rule of thumb, coolers, people and etc. should be comfortably located close to the stern. The rearward displacement will then effect CG and raise the bow.
 
Geoffrey & Brenda said:
Thank you Lloyd, i am now clear on the wave shield benefits.

However, i think a picture is worth a thousand words when it comes to the spray deflector revision. :rolleyes:
Click to expand...
You and my wife must be related....Nag, Nag, Nag.....Ok, i'll do it, Honey !! LOL
 
CcanDo, is there any negative reason that I should not build the boxing piece on an english wheel out of one piece? I guess your drawing would show if angular is better or smooth and rounded? Steve
 
StevE said:
Left seat Cherokee six 300, and the PA-140 which I learned in. Haven't flown left seat in some time, I had a heart attack at 46 years old (11 years ago), can't pass the medical for pilot in command. I take the right seat often with friends and still enjoy flying. I do have a small deposit on a Icon 5 (a sport amphibious aircraft). I have been the airboss for the aerobatic pilots; Patty Wagstaff, Gary Ward and Greg Connell. For those reading and having no knowledge of airshows; those pilots do the aerobatic flying and the airboss works with the FAA to obtain the airshow waiver and then over-see the airspace during the show (and ground operations). The airbossworld also be the logistic problem solver and the person that ultimately is the one whose backside is in a sling if the event had an accident.

BTW: All three of those pilots are excellent people, they love what they do, they enjoy sharing it in conversation with anyone, they are very approachable.

I really like flight so I have now begun flying giant model airplanes (gas powered) and turbine powered models. Even fly a float plane from my Bennie lounger :)

Steve
Click to expand...
Steve,

My hat is off to you, I've tried flying the models and get disoriented. Let's see, do I move the stick to the left, or to the right. In fact, they intimidate me !

That is a high profile crew you run with. I have always eyed the Pitts, though wondered if it was like the models. I have been told they are easy to ground loop. I went to flight school in Tulsa at Executive Flight. Classmates and myself had dog fights with students from Spartan. We all flew Cessna 150's, slammed the loose end of a toilet paper roll in the window and let it steamer. From time to time some one would get their toilet paper shortened by someone else's prop. (of course if your talking with your FAA buddies, I was never there, just hearsay) Besides, it was stupid. In fact, someone came in with popped rivets in the empennage. Of course, no one knew how that happened.

BTW, Do you come to the DFW area with any Air Shows ?
 
lakebum said:
CcanDo, is there any negative reason that I should not build the boxing piece on an english wheel out of one piece? I guess your drawing would show if angular is better or smooth and rounded? Steve
Click to expand...
Well, you should provide more information, let's start with color, then we need to do the math...Pie are round or is it, pie are square, do we need special air tools...sounds like we will have plenty of hot air ! LOL

If you are serious, I have no idea what an English wheel looks like. The part I know about is only a piece of flat sheet aluminum, sheared, and hand brake formed. The part is then fitted under the existing wing and welded in place, one side to the tube, the other to the wing. The result is an eliptical trapazoid box.
 
You must log in or register to reply here.
Back
Top