Prop Shaft

[ogshotgun]

Not every body is running that way.
http://www.toxicrocket.com/html/w-drive.html

maybe why its the worlds fastest and quickest drag boat , and toxic rocket isn't.

[ogshotgun]

How fast does your boat go?

its a heavy boat , it runs in the mid 90's

[ogshotgun]

Not every body is running that way.
http://www.toxicrocket.com/html/w-drive.html

maybe i missed something both of the pictures were in sync, both tips hitting the water at the same time , just like the last picture is in sync...

[ogshotgun]

I am probably wrong on this.
A hydro shaft never drags in the water so they can run huge shafts without drag
The vdrive or wdrive isn't way forward in the boat so the shaft is short, less spaghetti action going on.
A hydro prop has a shit pile more slip I believe also.
There's almost no boat touching the water, zero resistance on the prop and shaft, well not zero.
A hydro and a circle boat are apples and oranges.

yes apples and oranges
shaft doesn't touch the water , strut just above it , front shaft is bigger than the prop shaft
the boat hulls is a foot out of the water , the w drive is right against the capsule , but there is a mid shaft about 30" long than a prop shaft about the same length running two couplers one off the w and one under the boat
as far as slip i don't know but we grease the shit out of the props to make them slip so the boat doesn't slip

[ogshotgun]

Yes, yes, yes. Again, this is why I like the idea of use using modern machines to make these props.
And just so you digitizing haters know. I can draw a prop from nothing on CAD, I don't need a prop to copy. So if I ever decide to make one for myself, who should I send the royalty check to?

mail to me kevin ... lol ... lol ill take your money and not feel bad : )

[gn7]

maybe why its the worlds fastest and quickest drag boat , and toxic rocket isn't.

True. But I think there is way more that than how the props are orientated. I think driver input and E.Ts play no small part in determining the orientation of the props. You NKOW enough to flatly state that works on a outrigger canoe hull is the same a conventional hydro?
I never tried to push my setup on another GN, let alone 21 footer, or a SS/PS.


Smugness doesn't look good on you.

[sangerdan]

Not even close. The prop is running off/on the whole time.
When the ONE blade is headed down, it is doing the vast majority of the work to the point it passes straight up and down. Then its doing progressively less, while the other is beginning to do progressively more. But when they are dead horiz, neither is doing shit. No prop is loaded and unloaded like a hydro prop, and its only worse the more power you put to it.
With the twin props, they are arranged 90* out of sync, and the forward thrust is relatively even, although still off and on per side during the run. The fact they are counter rotating helps immensely with the stability of the boat, and counters the "side walking"

You can see the on/off in the rooster tails. This is actually a mild case.

Attachment 39619

I had to wait til morning when I was a little more clear headed and I still don't get what you are saying. Please talk hydro or flatty . I get the hydro makes no thrust when the prop is in the air. Are you saying a prop doesn't generate thrust for every degree of rotation that it is in the water?

[ogshotgun]

True. But I think there is way more that than how the props are orientated. I think driver input and E.Ts play no small part in determining the orientation of the props. You NKOW enough to flatly state that works on a outrigger canoe hull is the same a conventional hydro?
I never tried to push my setup on another GN, let alone 21 footer, or a SS/PS.


Smugness doesn't look good on you.

lol bob your funny but i looked a lot of photos on a lot of tfh hydros and the run there props in sync also , just like toxic rocket they are in sync or phase not 90* out ... don't know what works on a outrigger or hydro just know what works with the bullet hull

[sangerdan]

http://www.mercurymarine.com/propell...opellers-work/
This is the best description of how I have understood a prop to work. Water is always flowing in behind the prop to fill the "void" created when water is pushed off the prop rearward, otherwise a positive pressure is always building on the forward facing surface. The prop doesn't unload until the thrust surface is clear of the water. It begins to unload when the leading edge breaks surface and begins to load as the biting edge hits water In a flatty the leading edge never fully unloads. Interference from the strut and boat surface etc. would effect loading not the clocking of the prop .Does a box fan not throw a constant stream of air equally for each blade? Or is this all what Gn was saying and I was hearing it wrong?

[gn7]

lol bob your funny but i looked a lot of photos on a lot of tfh hydros and the run there props in sync also , just like toxic rocket they are in sync or phase not 90* out ... don't know what works on a outrigger or hydro just know what works with the bullet hull

Nothing is static in boat racing. Its entirely possible that the staggered prop set up is gone by the way side.
I know that when Faulkerson was running the Nitro Bullet and was a big part of developing the twin prop, as well as messing with a adjustable strut he was running staggered prop arrangement. But then, he was trying EVERYTHING!

The staggered prop setup was being used long before Faulkerson or anybody else running now even thought about.