Righty or Lefty

8122pbrainard wrote: Another term that can be used is rudder cavatation.

Correct me I'm wrong (and I know you will), but cavitation would involve the introduction of an air source into the water stream to help induce separation of the boundary layer of water.

Couldn't the rudder stall without introduction of such an air stream? A fluid is a fluid.

In my limited experience yes, I could turn the wheel all the way one direction and change nothing, for fear of what happened in the video I never tried turning it the other way, throttled down until it grabbed and told the plump fellow riding along to sit in middle of back seat unless he was looking to go swimming in a hurry

BuffaloBFN wrote: Rudder stall still baffles me. I guess I'll know it if I ever feel it.

I understand the concept of rudder stall. The rudder exceeds a "critical angle of attack" with the flow of water around it.

I understand this concept because this is what an airplane does when it stalls.

Water or air, a fluid is a fluid and they behave in similar fashions.

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Jody, I like the way you explain things. You MUST be an engineer. You don't let judgement or opinion cloud the facts. You remind me of Woody. And that is saying a lot!

I put a post of my engine build thread where I quote a conversation that I had with Woody today. To paraphrase Woody, it depends on the hull design or family of hull designs as to whether a righty or lefty conversion has a significant effect on how the hull behaves.

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Nope! Not an engineer! Educated masters degree from the school of Rayson Craft, Sanger,RickShaw,Karlsen,Correct Craft, MasterCraft, American skier and a minor in Hydroplane. Have a PHD in Obrien,Radar and HO.
Like Otis Sistrunk Attended the "University of Mars" before going pro!

Funny stuff. Learned a lot over the years just immersing myself in performance inboards for nearly 50 years. Spent all of the 90's working with the likes of my Bill Snook, Steve Meloon, Art Cozier and yes Woody.

I posted the Video as it is a classic example of rudder stall misbehavior (handling)due to some sort of bottom imbalance also due possibly to Mechanical failure. Boat showed signs of problems early in the race and the driver probably should have put it on the trailer at that point. I have actually come close to making ski boats do very similar things at far slower speeds. Cause and effect, luckily the Correct Crafts most all on these boards own are of designs that do not exhibit such misbehavior, basically due to the concave sides and attention to rudder design. Some of The competitions ski boat hulls even to this day can be easily induced into unsavory misbehavior due in conjunction of their hull bottom and barrel sides and rudder deficiencies.
Most all of the circle racer flat bottom's utilize right hand props and left hand engines... They drive off of the front of the engine not the flywheel side.

As for C&C design and fabrication of these crafts, most all of the boats being built today initially come off of a cad program and their plugs are cut on a large router. Then the tool maker puts the finishing touch on the plug as per the designer and or design team deems and "pooF!" we have a boat plug to build a mold from! The old school tooling is becoming a lost art as are the craftsman that facilitate the Art form!       

This is a big CNC machine:

http://www.adafruit.com/blog/2012/05/30/100-meter-cnc-machine/

65 'cuda wrote: Looks like these guys cnc theirs: http://janseneering.wordpress.com/2010/01/18/34-boat-hull-mold-ready-to-go-out-the-door/ I'm guessing nearly every modern hull mold is cnc'd.

Gary,
Thanks for bringing me up to speed on the CNC machining. I wonder if CC has started using the process for their hulls?

That's one big 5 axis CNC!!

65 'cuda wrote: Looks like these guys cnc theirs: http://janseneering.wordpress.com/2010/01/18/34-boat-hull-mold-ready-to-go-out-the-door/ I'm guessing nearly every modern hull mold is cnc'd.

Well put.

Tonali_III wrote: I will agree that the effect on older hull designs, the effect is minimal. There simply was not the ability to make a hull or even study a hull that was so precise that propeller rotation played a large role in handling. In our present day of CAD hulls and computer aided wind tunnel(or water tunnel?) testing, we ARE able to design and manufacture a hull to such tight tolerances that any change outside of the factory will produce a result that needs to be compensated for.

Tony,
I have to ask you how you came up with this idea about old hull design.

New hulls may be designed by CAD but tell me, how do they make the molds?? They are NOT CNC machined!!!!!!!!

I've seen both, but I'm going to guess those boats were adapted to the capsule and not built for it. There is of course some contreversy about the capsules and the seat belts, but I believe I heard they are mandatory for most this year. I think most of the K boats at Long Beach this past summer had them in the center. Personally I think they look best without, but after seeing a handful of boats literally break into hundreds of pieces and then having a beer later with the guy driving, they do work.

The trouble with owning boats with RH and LH engines is remembering which way the one you're driving is going to back.

Sometimes a RH engine can be had for less money than a LH, but definately not RH specific performance parts.

Alcohol is bad for your motor, really?

I would be pissed too, not very often someone does that to Scarlata with any kind of boat.

Jody are the K Boats set up to turn one way? I remember the Crakerbox drivers saying it would flip if we turned it right. We had the K Boats at the drag race one year, very cool they don't usually travel this far from the west coast so they haven't been back.

http://www.youtube.com/watch?v=lCmtnrYipI4

Thought I would post a video that exemplifies an unsavory handling condition that is probably induced to having too much hook due to failed cavitation plate or it's operating hardware. situation sets up what may be described as rudder stall.. Anyway check out lap three where the boat exhibits a view of things to come.    

If your pulling in so fast you don't have time to stand up and walk across to secure the boat you need to work on your technique. You can dock on either side, but I got to believe there was something that caused them to call the correct side port.

74Wind wrote: AAM196 wrote: The only thing I don't care for about my 99SN is the fact that it backs to the left when docking... Old-school i guess, in a lifetime of boating never been in one that didn't back left. Backing right would sure take some getting used to.

Our 83 mc s&s backs to right due to the lh rotation.... easier to dock as driver can just grab dock but leans hard to starboard w/o passenger. I find my 99 sn levels out nicely onces on plane.

Cars usually lean to port for some reason. Cheeseburgers?