Weird Jet drive setup

[QC]

I am placing this here as it is not a drive or inboard engine problem, nor is it really an engine topic . . .

Found this "Dual Drive" setup on eBay today:

Here's the listing

Anyway, single engine with Dual Jet Drives. I have never seen one and wonder if anybody else has. The listing notes it in the title, but then fails to mention anything more about it. I see only one control which tells me that you cannot separately manipulate the reverse diverter deal things. Seems to take away one of the best possible features: the ability to spin within it's length for docking etc. . . . Not sure how it would stack up for efficiency either and there must be something that doubles the output shaft from the engine to split the power and drive both jets. May simply be a result of so much power, but I have seen single drag jets before, so that doesn't really seem to answer the ultimate "Why?" . . .

BTW, my 23 footer with a 6.2 Bravo 1 goes 57, and it only takes 661 bhp to get this super duper setup to push a 24 footer 60 . . .

 

[TilliamWe]

Re: Weird Jet drive setup

If not able to be controlled separately, I am not sure what the advantage is either. Many more moving parts, there has to be a custom transmission that runs the two separate pumps. I am most surprised that it's a 2001 model boat. So that makes it very modern.

On this note, there was some drag boat (maybe a line of them?) that had two propshafts off one engine. It was supposed to be more efficient, but as I remember, making the props work together was difficult. One pushed harder than the other and the boat was very unstable. That's what I think would happen here. As one pump wore more then the other it would get hard to steer it!

 

[Benny1963]

Re: Weird Jet drive setup

may be just a spare hanging back there ,
neat lookig though.
i like the jet drives but they suck up all your hp
and the water i run in in louisiANA IS TERRIBLE

 

[QC]

Re: Weird Jet drive setup

Many more moving parts, there has to be a custom transmission that runs the two separate pumps.

Actually this could be a simple chain drive deal like some direct drive couplers (can't recall what that's called). It doesn't need a transmission, just something that takes one shaft and drives two. No clutch or reverse necessary. Definitely not pretty though . . .

I am most surprised that it's a 2001 model boat. So that makes it very modern.

I was suspicious at first because the graphics don't look that new. Hull number appears right though. This manufacturer has stayed somewhat conservative and are known for older stlye drives and looks . . . So who knows? Seems very odd to me.

 

[Bondo]

Re: Weird Jet drive setup

Ayuh,.....

Jim Wilks of Wilks Marine was working on some experimental Twin jet drive a few years ago,....
I wonder if this is the Fruits of his thoughts,.....
It was to use a clogged belt,+ related Housing to keep things in line when the Power was All On....

 

[JCF350]

Re: Weird Jet drive setup

Another experiment gone awry.
Seen a lot of strange stuff in the past 30 some years.

But they always make you wonder

 

[tashasdaddy]

Re: Weird Jet drive setup

a jets backing is so poor, i doubt you could get it to rotate, seems like the forward thrust, would override the diverted thrust.

 

[Bob_VT]

Re: Weird Jet drive setup

Mant drag boats use dual drives and a gearcase to gear the props up for even faster roatation.

Dual jet drives would be similar to dual i/o where the drives do not have to work as hard.

60 MPH with 600 hp is about right for a good size boat with a jet drive. They are tough to make go fast w/o ton's of HP.

 

[Drowned Rat]

Re: Weird Jet drive setup

It seems the engine's power split like this would mean a slower boat, unless like QC said, maybe it's already overpowered to begin with. With the drives that close together, I don't think it would spin anyway. And even if you could control one or the other reverse diverters, you'd be diverting exactly 1/2 the power no? You wouldn't be able to feather the throttle on one side or the other to hold your station while spinning. It would be unmanagable trying to use it like a twin screw.

 

[Viking77]

Re: Weird Jet drive setup

It looks like Photoshop to me.

Look at the right nozzle. There is no ID stamp or brand name on it.
It is like someone did a cut and paste to the picture.

I think it is Photoshop.

 

[The Great Escape II]

Re: Weird Jet drive setup

This guy's "buy it now" is listed at $55k. You got to be kidding me!