Fakeleg: Are you pulling my good leg? The short answer with "tongue in check" is 90 degrees maximum pitch. Beyond that you would be blowing air forward. It would be good on a hot day but you would be "backing up" Seriously; There is alot of missing information in your querry; Wha...

Reply: Southern Airboat 11-14-11 Good Morning Folk: Reading the comments this morning, I find a request for a graph to explain all this. Great!! I just went to the website of the Crate Engine Depot Company. (I also see the money spent chart posted & its true.) See http://www.crateenginedepot.com...

Wild Bill: "So a boat with the rudders midpoint of length centered with the height of of the propeller center-line will have less torque roll! interesting thread! Thanks!" Sorry, but Not True. Excessive boat torque roll that might me caused by a "high pitch propeller setting" cau...

November 13, 2011 Dantheairboatman: Dan: I have read and re-read your last post to glean your meanings. I am intrigued with the testing equipment that you mention and would like to know more about it. I consider the final best description of the efficiency of any airboat setup is to be able to state...

Reply; Thanks for the comments and to those that viewed the thread so far. The action word in the Thread Title is “Choices”. It is not my intent to “pitch” (a play on words) for any particular setup, but rather to have us see, if interested, and understand what is going on with all that air that is ...

This Text is copied from a communication that I recently had with Chuck Rackley of Airboat Pros. We were discussing the most fuel efficient and quietest combinations of reduction ratios and propeller pitch settings (degrees of pitch at the tips of say a Maximus propeller set). To help describe the i...

Melonator: AirRanger comments; (cliff notes version) A good starting point is to get yourself a torpedo level and an angle finder. Use the level on prop hub to confirm prop is level horizontal. Use angle finder at one blade tip, adjust blade to (for example only) 10 degrees. Snug blade. By hand turn...

gyrocopter582 & Chuckett: I have been following this thread and am impressed (as are many others) with the following, ideas & and activity about the Ecotec Engine. This "Fuel efficiency Thing" is taking hold. The price of gasoline can only go up, way up with future inflation. I am ...

Ruagatr: flying fish: David GSO 480: Answers; I hope to achieve what "Ruagatr" was talking about with his small engine years ago for modern car motor boats first and aviation motors as the project might continue. A top preforming airboat in its first few mph of lower speed range needs to v...

I thought It would help to add pictures again to help bring this thread back to the Varible Pitch Propeller Question. I would like to see comments bad and good, if any, about the variable pitch new propeller set up to help me decide if we want to produce this preformance improving product for airboa...

10-28-11 Flyingfish: A great amount of thought was given to your question of the need for a lower additional bearing to augment the rear main bearing of the small block GM motor that this unit was designed for. To be able to design a unit to hold the HP and still be lightweight, long lasting and eco...

This post is a result of and continuation of Andrew's "Variable/Constant Speed" eariler post in Tech Talk. Because the subject of our existing project of a "new for airboats, Operator Adjustable Variable Pitch Propeller project", that was tabled a few years back because of the ec...

Thanks for the clarification David. So with this design, the "drive shaft" or "axle" must be hollow to deliver the pressurized oil, correct? Will your design be interchangeable with current Belt and gear reductions or only with the Blue Lightning? Andrew: So far our variable pit...

David, Thanks again for the post. I really enjoyed reading it and appreciate your detailed reply. I have only owned one Water Walker prop but can honestly say I love it. It made my GPU far out perform what it did with a number of different wood props. I hope you get this system into production soon...

OK, I think I have figured out how to add pictures. Please view these with my earlier post,
Thanks,
David Wine

10-26-11 from David Wine Water Walker, LLC Andrew: I was drawn to your post this morning and respond with this up-date report on our “Operator adjustable airboat propeller” project at Water Walker, LLC. I am writing a detailed summary so as to let everyone know our current status. History and backgr...

I just learned that a program on the History Channel (H-2) will air tonight at 10:00 Pm Eastern Time. The subject is the assembly and supprising history of airboats. Mark's Airboats from Lousiania will be featured I plan to watch it..
Water Walker,
David Wine

ZoomZoom: Thanks for the kind remarks. In the past years we have done many thrust tests and always faired very well against competion. Controlled test as to fuel burn etc, however the answer is no. On airfoils; Our propellers use airfoils that I developed myself supprisingly using a PC computer prog...

Oct. 8, 2011 ZoomZoom: Thank you for your continued interest, your insightful comments and good questions. Indeed this thread has morphed from engines and boxes to propeller dynamics for airboats. It’s probably not fair to Jeff to lead it away from his first questions. Having said so, none the less,...

Chris: Several answers to your several questions. The 10.61 square feet of disc area "statistical constant" is not a formula, but rather is a statistical average of thousands of well preforming air thrust propeller applications. Wings on airplanes and propeller blades produce "work&qu...

September 30, 2011 Answer to Jeff Kreger’s questions; 1 - What impact does the number of blades have on the propeller disc area? If any? Medium HP driven air propellers for airboats & airplanes are constrained in their designed disc area by; • The relationship of the disc area’s circumference to...

Response from Water Walker; David Wine. Thanks “Chuckett” for telling me about this thread on the Forum. “Zoom Zoom” you are perceptive to ask “Where did you get the 10.61 HP per sq. ft. disc loading as a constant? Chuck got it from me at Water Walker. The history of this “rule-of-thumb” constant wa...