Need some opinions? Chuck and other mini builders

[brlcla]

http://www.takenterprise.com/TAKII.html

Going with that small a prop 46" with only 1.5:1 reduction, how much efficiency am I loosing over a 1.69:1 or 2:1 with the whirlwind, ivo, or warpdrive props that are 60-65" dia.

How much thrust am I losing in those 20" of prop. Just need some professional opinions.

[chuckitt]

Hey brlcla, Thanks for joining the mini forum. We are glad to have you. The reason for the 46 inch prop on the jon boat is the boat isn't wide enough for a longer prop. A 60 inch prop on a 42 inch wide boat would torque over too much. A shorter prop must have a higher ratio reduction to develop enough prop speed to make it work. They are turning the prop at 2600 RPM with a 1.5 to 1 reduction. That means the engine is turning 3900 RPM. With a 78 inch wide hull and the same 40 HP Kohler, we would use a 60 inch 3 blade Warp Drive, a 1.69 to 1 reduction and turn the engine at 3850 RPM and the prop would only be turning 2278 RPM. This setup produces no torque roll, the slower prop speed produces less noise, and the wide hull cruses about 1 inch in the water making very little wake. The pitch on the prop was 9 degrees.
All adjustable props have a certain pitch range that works best. Not enough or too much pitch and the efficiency of the prop falls off. The pitch range must be considered when you determine the length of the prop, the reduction ratio and the power of the engine. There are many more important factures that make an airboat work well. If the engine is mounted too low with a short prop, you may not develop enough trust to push the bow down to make it run on plane. Engine mounted too high and prop too long, may make the boat run on the noise making it hard to steer. Props were easy to fiqure when they were all wood and mounted direct drive. We could look at a prop on a boat and tell how strong the engine was if it turned a certain RPM.
Now with all the different style carbon blades and reduction ratios, we had to run them all to see what worked for the size and weight boat we were building. I hope this helps. Thanks, Chuck

[brlcla]

I know the smaller prop is because of the boat size. But was just wondering if you could guess about how much thrust I gain with the 60-65" props on 6-7' wide hulls vs that little set up.

But the advise about motor location and prop length I have never been told before. That explains why that little boat is bow high. I am really appreciate where the sport of mini boats has come over the past years. I would of enjoyed one of your boats or Paul Dixon's boats. I know you were tryin to come over here to Louisiana to show your boats, is that trip still planned? I have been recently looking hard at the new Mini Airranger from American Airboats in Orange, TX. They are only about a 10-15 minute drive from my house, so that boat became my more likely choice. They also know what the water and area is like around here and can build a boat accordingly, not saying you cant but its hard to discribe the LA marsh to a Florida builder, just something you have to see to believe.

Oh and is there any video of the 084 running?

Thanks,

[chuckitt]

No, but I hope we can get one made this weekend. We have been working on my son's house and trying to build airboats too. Not enough hrs in the day.
We still would like to come to LA. but the available funds don't allow it now. One of my venders is building a 40 ft trailer to haul 3 mini airboats and he wants to have 2 trailers ready and we try to make the trip in the spring.
Thanks, Chuck

[brlcla]

Well I hope to have my Mini AirRanger from American Airboats by then. Maybe we can find a place to take a ride. Maybe bring some people intrested along and make a sale or two while you are up here.

[Snapper]

hey br you do know how much they are asking for that boat , don't you ...

[brlcla]

Yep, sure do. About $5K more than Chuck's. But willing to pay that for convenience and quality. Also like I said in the other forum its only a 10-15 minute drive over there if I have issues with the boat later down the road. They know what the marsh is like in S. LA and S. TX, and know what kind of boat the area requires. The benefits far out weight the negatives of the price to me. And I have always been the guy that is willing to pay for quality and what I want.

[Snapper]

other than a tricked out camo job , the hull looks the same , I wouldn't be surprised if it wasn't the same hull , chuck uses for his rd2 , but no doubt it is a sweet looking ride for sure , and hey by the way its good to see ya back on the boards posting , you sure have been gone a long time , you must've found plenty of old rusted pipes out their in the marsh since the last time you posted , hehe ... well either way I want first ride when you get it ...

[brlcla]

Actually Snap I went through a job change. Project Engineer for one of the local plants now. And no it is not the same hull. American builds all of there hulls in house. American Airboats is a fully equipped manufacturing facility, only thing that isn't built by them is the prop and the engine. The reduction on that boat is also custom machined by them.

[chuckitt]

American Airboats does build a quality airboat and builds most everthing inhouse. They are one of my best customers for the ss mufflers for the big airboats. I like the way their mini looks. I think the only thing i would do different is make the cage a 2 hoop cage instead of the 1 hoop cage. Now, if the bow hunter comes with the boat, I might buy one myself.
( Then Diane would kill me.) Chuck

[brlcla]

Nice one Chuck, some of those Girls of American Airboats would get any man into trouble. Nice to hear a experience quality builder like yourself speak so highly of another manufacturer.

[David]

I would agree with Chuck have him build you a 2 hoop cage what size is the aluminum and what thickness

are they gonna build mini hulls just to sell also

[Spyda-Ryda]

I've run mini and full size airboats in south Louisiana all my life and as much as I like the american airboat mini, I highly doubt that it will run dry in a louisiana marsh. Unless it's winter and there's a light layer of water on top. But still the first piece of "FLOATON" you cross is gonna stop you quick. The power to weight ratio isn't good enough to run dry LA marsh. It really depends on what you plan to use your mini for.

Again just my two cents.....You guys know what opinions are like and everybody's got em..

[brlcla]

Spyda I agree, it will never run dry at my lease and never had expectations of it. But it will go places a go-devil can't. Longtails and surface drive have one major limitation, they can not stop on solid mud or they would never get out and if you do get out you probably worked the motor for an hour moving a few inches at a time. Both need some sheen of water on top of the mud. An airboat even if it is a mini can get off of mud from a dead stop, that is my reason for wanting a mini for hunting season and it is easier to hide. Also plan to use it as a ride boat in the summer and to fish/bowfish. And I do not believe "Floaton" will stop it, but it might depending on how thick the patch. I have been around Airboats since I was 12. I know what my limitations due to HP are around my lease. I ran an old VW Aircat for years before the hull became too waterlogged, it could barely push itself. This is all about being able to enjoy the boat year round and not burn 5 gal/hr but 5 gal/day.

[Spyda-Ryda]

I hear ya man, airboating has been more of a lifestyle than a hobby for me. I started driving my dad's 0540 Lycoming at age 8. It was one of those, dad can you tape a piece of 4x4 to the pedal so I can reach it knida things. I can remember being so young and not strong enough to turn the rudders with throttle, that I'd have to let off the throttle push or pull the rudders, hold tight with both hands and get back on the throttle to make turns. I'm sure there are a few other guys on here that can say the same. Once he saw that I could handle the lycoming, we put my own rotax mini together soon after. We decided that airboating was something that we really enjoyed and wanted to share it with everyone. Thus airboat tours was opend in 1990 and a call was made to Classic airboats to order a 18x8 with a 454 Chevy. Now we have 5 boats and a successful and enjoyable family buisness.

[brlcla]

Spyda from you address I assume you are the large tour operation at the foot of the 90 bridge over dufrene. I hunt out of the Theriot area and have driven that way several times over the years. Used to take 90 from Houma and hit 310 to 10 to 55 headed home. I live in LC now and take 90 the other way.

[Spyda-Ryda]

Yeah, that's us. We're located on Hwy 90. eastbound, just 1/4 mile west of the Des Allemands Brdige. The bridge is the borderline between St. Charles & Lafourche Parishes. I'm not sure if we'd be considered to be a large tour operation though. More like a small, family owned & operated tour company. We specialize in smaller and more high performance boats than the other tour companies. We've also been in buisness for longer. We were the first airboat tour company in Louisiana.

[brlcla]

Have you started to look into guided bowfishing hunts for Reds?

[Spyda-Ryda]

No man, we stay busy enough with tours.