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counter rotators

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:?: :?: :?: are they really 30% quieter ? 30% more thrust? reduce fuel consumption? durable? The idea sounds great--- I'm looking for a very dependable, quiet as possible, dry ground running boat. I'm wondering if a big block with a four blade prop would do the job for much less $$$.
 
Mark Robicheaux, from Mark's Airboats, told me that the counter rotator is a whole bunch quieter and about 5-10% more efficient than a standard rigged boat.. Don't know about the economics, but a 15x8 with a 502 (popular around here) or 572 is adequate...even with a load.
I know personally of one counter rotator he built with a 650hp 502 and it has been reliable and awesome performer. But big $$$$$$$
I'm sticking with my 12 1/2 ft x 8 ft fiberglass Apache powered by a O540 angle valve. I can do everything they do and as quick as long as I don't haul anymore than 1 person and 2 dogs.
 
The only one I ever saw in the water is at camp mack and I was not impressed considering the cost. He was stuck on the hill and I drove a couple of circles around him checking it out to try and help if he needed it. He got out a squirt bottle and broke loose finally. So I am not sure about the thrust part and as far as quiet well didnt seem quiet to me either. I had a full load on my boat 4 adults one kid and coolers. he had one other adult but he was a 502 multiport fuel injected diamond back hull but it looked heavy. So for my opinion nawww put the money into horsepower. Oh yeah his motor was in the bottom of the boat aslo that really looked like a heavy drive unit.
 
The diamondback boats are great water boats they tend to run on their nose,and that is not good for running the hill. I am personally not impressed with diamondbacks performance. But they do build a great looking boat. There is a guy we run with has a 14' diamondback with a gm-502-502 and a long counter rotating belt drive the boat is a dawg will not run the hill at all. I believe with the correct setup it would be awsome. I run a 14' cutdown hammant with a 408 c.i. gm 420 hp with a 2.38 stinger box and a 3 blade composite prop. I can go anywhere I want and go as fast as i want also.
 
The counter rotator and the low mount engine reduction drive adds quite a bit of weight to the boat. Stabilizes it yes, reduces torque (but IMO that is not a serious problem on most larger airboats), and is slightly less noisey according to the decibal meter(but after you break about 95-100 it is just plain loud). I was told that the paired set up ends up adding about 700-1000 pounds to the boat, sounds like alot, so don't qoute that weight.

The gear oil is costly, needs regular changing. I know of two around here and one leaks oil, changing the seals is a pain in the back side. If something bad occurs then there are more blades at $450.00+ apiece to buy. Lots of added money, more parts to break on a machine that are trying to continually rattle itself apart, more maintenance, and more weight. Yea, a proper system can push the weight, but that is at least two less big men and gear you could carry.

If you can find a reliable builder of a higher HP engine and you keep your foot out the carburator, then I would agree and go with more HP and standard belt drive.
 
I rode in a huge barge style Classic airboat it was the biggest airboat I have ever rode in. It had a counter rotator with a stock iron 502. We ran the hill putting it was amazing how effortlessly it ran dry. The other four boats with us had too grind um pretty good to run the same hill and a 220GPU boat had to park and walk in.. Oh yea there were four people in the Classic boat and I’m a fat F$#@ myself I weight 302lbs. One boat was a 16ft Diamond back with a hot rodded 509 big block he didn’t even have a passenger. Here is the funny part the counter rotator boat that was over 20ft raced the 16ft 509 Diamond Back boat in the water and waxed him. I was very impressed with the counter rotator. I really like the fact you can talk at a normal tone of voice and here each other clearly.
 
Gentlemen, please allow me to weigh in here.
All of this talk about counter rotators is making me spin.

First and foremost and without argument, counter rotators are expensive. The expense is not only in the drive unit, but also in the double props, a double expense.

Secondly, counter rotators are "noisy," not in prop noise while running, but at idle. The drive unit rumbles, grinds and clanks. And, that is new. Put a few hours on it and the noise gets worse.

Third, all of the promo-talk about 15%, 20%, 25% and 30% is all sales talk. I have heard it all. It is just a matter of what sales person you are talking to. Initially, the counter rotator was promoted as being 25% quieter, 25% more fuel efficient and providing 25% more thrust. Then the claims were backed off to 15% and maybe there weren't any quieter.

Blah, blah, blah . . . .

Is the boat equipped with a 2 blade or a 3 blade leading prop and is the push prop 2, 3 or 4 blades?
What is the engine size?
What is the size of the hull?
What is the size, make and horsepower of the engine pushing the props?
Is the engine equipped with mufflers and if so, what type?
How is the engine exhaust directed, out the stern through the hull, out the side, overhead or opposing? It all makes a difference in engine noise cancellation.

At this point in time NO ONE has done sufficient research and testing to prove any of the claims.

The only thing that is certain is that counter rotators are expensive and they provide a greater opportunity for mechanical failure. Just something else to go wrong and when it does it will be expensive to repair.

In my personal opinion, counter rotators are sexy but they are not worth the money spent on them.

Any big block engine (454, 496, 500, 502) properly equipped with a standard straight drive composite prop, (2, 3, or 4 blade) optimally tuned should provide any airboat with more power than any operator would want.

If you want more power, it is my suggestion that you put your money in a bigger engine and increase horsepower, rather than throwing it away on something that is relatively unproven and very expensive.

WaterLizared 8)
 
Water Lizard - You are right about those counter rotators making noise. I am around one quite regularly and noticed that people that have never been around them or just around gear drives tend to make sure they have their cell phones or a walkie talkie of some sort on them when that thing is started up to warm up. Rumble, Rumble, Rumble, - sort of sounds like something is about to go out, and they don't want to be stranded in BFE. But it has been checked out and the owners were told that was expected.

Second, that back seal on the reduction gear is a real witch to change. Either pay someone through the nose or spend about a full day working on it. (2 or 3 days if you are like me and my friends, we are just plain slow,). The guys running that Classic rig over here were told to expect to change it every 250 or so hours. And that is crazy.

They produce less torque, but typically require a 17 footer to put the counter rotator rig on. And at that size torque is not a real big concern.

They are quieter when cruisen on the water and you can be hear over it if you talk rather loudly. But when you run the grass flats around here in SW LA or SE TX, that throttle is getting pushed on all boats that I have ever seen and when any big block turns 4000+ RPMs it is noisey. There is no way around it.

I vote with Water Lizard, spend those extra dollars on a bigger motor, more horsepower, or rig that boat out with a drop ramp/grass rack, the bow fishin lights, spare parts, or something extra that make a sweet rig.
 
I was just making a statement from my own personal experience with no personal agenda involved. I have never been able to talk on any running airboat accept the counter rotator that’s a fact. My personal opinion is why own a airboat over 16 feet anyway. I do know there is no way a huge boat could have done what the counter rotator boat did with only one prop. Natural physics would not allow it. I prefer a 600hp small block Chevy on a 13 ft hull but that’s my opinion. I have owned 4 different rotor boxes with out one failure. I do know where all of them are now and none of them have needed any repairs. One box had over 300 hours with a 600+ HP motor on it and a 250 HP nitrous kit. I never had a single problem. I also put a clutch on one and never broke it either. The reason these gear boxes make noise is they utilize spur gears this is the strongest gear design available. A helix cut gear which is much quieter is also much weaker and cost twice as much to manufacture. A very good friend of mine runs one of the first rotators ever made and he has at least 6 years on it at a minimum of 150 hours of running a year. Without a single problem. I’m curious do either of you own a boat with a gearbox on it? I have also ran a stinger box a chain drive a direct drive and a piece of crap Franklin belt drive, the belt drive by far was the worst. It weighed a million pounds came in too small a ratio an torqued in the same direction as the motor. When I floored the boat it rolled up on it’s side. I switched to a gear box and everything was better. But this is in my specific application if I owned a 20 ft boat and didn’t care about speed or performance and the boat was so big it didn’t roll over I’m sure a belt drive would work just fine. As everything else in life nothing is the best at everything and beware of the person that thinks something is the best in every case. I don’t mean to annoy anybody but I do allot of technical posts on various engine boards and run into people who think because something works for them it’s the best thing for everybody. I have learned these same people usually have only tried one or two different combinations and base everything on those one or two experiences. Hell if I didn’t try differant things. I would still be driving around in the marsh on a Gore hull with a 125HP Lycoming that has to be hand propped. Well have a happy Halloween I’m going for a boat ride.
 
Thunder - Nothing but just personnel opinion from me as well. You are right, I have not ran as many combinations as you. Actually, I am a fan of the Lycoming's 0-540, especially the parallel valve engine on riveted 11.5 to 13 footer Palm Beach Style hulls. They just do the job we use them for alittle better than most of the heavier welded rigs. Never saw much use for most boats larger than 14 myself, unless you are fishing or hunting big water in south Texas. Then you need that 18/20 for stability.

Have ran a ton of the 350s mainly the older ZZ3s or standard marine 350s (310 to 335 hp), with a few ZZ4s, almost always with the old style belt drives. I was working with the seismic industry running boats for about 3 to 10 hours daily, 7 days a week for several years. Didn't have any problems with those old belt drives and most of those guys that owned the boats said if it ain't broke why fix it. We needed those boats running with as little maintenence as possible and those hopped up motors take too much expertise and money to run 25 to 80+ hours a week. Everything was over the counter and swapped out as easy as possible. Like you say torque is mother, but could be controlled. But we were not pushing 500+ ever.

I saw only a couple of those gear box drives in the seismic field in the early 1990s - and we dragged them out with either dual airdrives pulling with ropes (a crazy ride) or with a track buggy. Those guys were getting a paid for 7-10s if their boats were in running order and when they went down, no pay. Heck it could have just been lack of maintenence from the owners. I don't know.

Right now, we have one gear drive on a stock ZZ4 at work. About 320+ hours on it and just under three years old. Rear seal leaks like all get all. Hull is a lead sled (bad design) and nobody likes it, porpoises like crazy even with the trim tab and will not run the grass marsh cross country. But it is what the boss ordered. LOL

Those rotators are impressive, they are the only ones you can talk over, but I still wear plugs and muffs on any airboat, the hearing is bad already. They push quite a bit and I agree, there is no way to get the same thrust out of one set of props, even with the second pair cutting turbulant air. However, there is one just across my street and it has some issues. Like my posts said, they have had a few headaches with it. Never owned a counter rotator, just too much money to consider.

Never had chance to run anything but stock crate engines with the automotive engines. I run 0-540s with direct drives now. Some minor tinkering over the years to get alittle more hp out of them, but in the long run, have stuck with stock since they seem to last longer that way, in my opinion. Just never had the money to play with more than stock.
 
Oh yea you see the point. I think you can mostly group the best airboat per individual into these needs. 1st is the budget airboater it’s hard to beat a 220GPU in this category. If you’re a light guy that rides alone most of the time and cares about fuel economy you cant beat a 180 Lycoming, If you’re a hunter or like a simple light rig that runs strong you can’t beat a 6 cylinder aircraft. If you push a big boat whith a large load or want people to think the world is coming to an end when you punch it you can’t beat a car motor. The reason I like car motors is you can make gangster horsepower and don’t have to rely on a connection to buy your parts from. Every part in my motor was made this millennium nothing is from the 1900's. However when I’m retired and don’t care for anything but a nice pleasant ride on the river and don't care about burning up the hill or racing. I might consider a aircraft boat. But I will not know until I’m at that point.
 
Hey Marshmaster Pat, I was reading about your boat with the ZZ-4 & gear drive that the rear seal leaks like a sieve. I had the same motor with a stinger soft drive on my old boat.That gear drive,(I thought) leaked big time too.I had oil dripping down directly from the rear outer seal,all over the flywheel area,& in turn all over the prop But after checking the fluid level in the gearbox & looking into it further,I realized this wasn't gear oil.It was motor oil.I was puzzled because the first & only place above the flywheel where there was evidence of a leak was at the output seal of the box. I finally found the source of the oil. What it turned out to be was a leaky seal on the distributor shaft.Vaccum from the prop was pulling oil up into the distributor housing until it filled up even with the base where the cap meets the housing.Then out it came.It just happened that what oil didn't go to the prop landed where the rear seal is located.How it still ran with all that oil in there I don't know. Although oil never went on up into the cap itself. To tell you the truth I never put in another distributor to fix the leak & never had a ignition problem.Whenever I saw it getting messy back there I just pulled the cap & soaked the oil up with a paper towel & that would stop my so called gear drive leak for awhile. This might not be your problem but it is something worth knowing. Master Blaster
 
Thanks for the tip, I will look into that, but the oil has a greenish tint like the gear oil we are using. But will look for a leak elsewhere as well. Considering this boat has been a one problem after another from day one, nothing would surprise me.
 
I know that Panther makes a CR but you have to buy a boat from them to get one. Are there other brands? What are the drawbacks of the various brands?

Any input would be great
 
This panther is my 11 boat, I have had boats with direct drives, belt drives, gear drives & know the Counter Rotator.

The Counter Rotator is mounted to a 572 pushing a 21x9 tour boat. We mainly run dry of 8-10 people. The water level is gets very low, so sometimes we have to start on dry ground.

I went with this set up also because it quiter going down the river so it doesn't bother the people on the banks.

It does have that clank noise at a idle, but I will put up that noise to keep the thrust it provides.

It would be hard to change my mind about this set up. It is expensive, but it works very well.

Tim Bryson
Fremont, NE
 
Basket: I'm picking up my new boat (counter rotator and all) on April 10th from Diamondback (see my post under American Airboats POLL to see how this decision came about)

Thanks for asking!!!!!! I can't wait!!!!!!!!!!!
 
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