Pac 22 Surface Drive

[ALANT]

Has anyone fitted a Pac 22 with a surface drive?
Pros/cons don't do it?
Just sold my boat so getting withdrawl symptoms
Anyone up here in Scotland looking to sell their rib?

[Cookee]

Originally Posted by ALANT

Has anyone fitted a Pac 22 with a surface drive?
Pros/cons don't do it?
Just sold my boat so getting withdrawl symptoms
Anyone up here in Scotland looking to sell their rib?

Why would you want to do that? And what power would you put in it?

[ALANT]

Why; less moving parts than z drive less power loss.
Size of engine about 250-300hp 6cyl diesel.
Why hasn't it been done a few jetdrives which don't seem to work but no surface drives.
Just toying with idea for summer project.

[Cookee]

Originally Posted by ALANT

Why; less moving parts than z drive less power loss.
Size of engine about 250-300hp 6cyl diesel.
Why hasn't it been done a few jetdrives which don't seem to work but no surface drives.
Just toying with idea for summer project.

Why not: More expensive, only ever used on high performance stuff - although I don't know the theory I do know they are less efficient at lower speeds, less manoeuvrable, and big prop and drive stuck out the back of your boat.

Jet drives do work, but most efficient at one particular speed. Bravo one drives are generally accepted as working fine up to about 315hp, beyond that you have to have more respect for the drive!

[DGR]

Would the Yellowfin address any of those 'unfavourable' issues, or is the whole surface drive idea too much of a compromise?

[Polwart]

Originally Posted by DGR

Would the Yellowfin address any of those 'unfavourable' issues, or is the whole surface drive idea too much of a compromise?

Yellowfin is not a surface drive, or am I miss understanding your question?

[Cookee]

Originally Posted by DGR

Would the Yellowfin address any of those 'unfavourable' issues, or is the whole surface drive idea too much of a compromise?

As Polwort says Yellowfin is something totally different - Surface drives are not a compromise solution, you should think of them as being a solution for a different application. Trimax and Arneson are the two main drives - Sunseeker use Trimaxes a lot on their sporty boats, a friend has a triple diesel Superhawk (I think it's 53') with two speed Trimax drives, and if you want to get more than 315hp diesel power into the water, the only mainstream route is surface drives or shafts - for instance the Yanmar 440 doesn't have a sterndrive that will reliably handle that sort of power IMHO!

[DGR]

Originally Posted by Cookee

As Polwort says Yellowfin is something totally different ...

OK - I'm probably just confused because they call it a 'Variable Surface Drive'.

I understood that to mean that it acts more like a propeller at low speeds (i.e. completely immersed), but like a surface drive when on the plane - as I can't see how the whole drive would stay in the water when on the plane!!

ANYWAY - didn't mean to thread-jack, just curious as to how good or bad a Yellowfin might be (especially on a 7.8m RIBCraft with a 315HP Yanmar... )

[Cookee]

Originally Posted by DGR

OK - I'm probably just confused because they call it a 'Variable Surface Drive'.

I understood that to mean that it acts more like a propeller at low speeds (i.e. completely immersed), but like a surface drive when on the plane - as I can't see how the whole drive would stay in the water when on the plane!!

ANYWAY - didn't mean to thread-jack, just curious as to how good or bad a Yellowfin might be (especially on a 7.8m RIBCraft with a 315HP Yanmar... )

I have only seen a couple of youtube videos of it working and the website isn't saying anything at all interesting, but I haven't heard of any drives being fitted to boats, maybe they will start appearing if they aren't too expensive and complicated

The Yellowfin says it is the perfect drive for everything so that's obviously the one you want!

[DGR]

Originally Posted by Cookee

The Yellowfin says it is the perfect drive for everything so that's obviously the one you want!

Yes indeed, not to mention the 60% increase in efficiency, 50% speed increase, and 100% increase in the number of bikini clad babes I can pull on a day at the beach...( )...and one of those benefits caught my attention......

It's supposed to be available this year (2008), but would be interested to know how reality stacks up to the hype.

Until then, my Bravo 2X has survived over 500 hours of RIB-Riding at 35+ kts, and it seems to be coping quite nicely...(fingers crossed, touching wood, etc, etc, etc)...