Looking for more info on pods

[Dash]

Was browsing this morning looking for more info on pod drives (Zues in particular), Came across this forum, joined up and I'm hoping that I'm not asking my questions in the wrong place.
I've got a 38' Bruce Roberts designed Aluminiun Waverunner that I use as a six pack charter boat. The boat was built in 96 and is powered with a pair of Volvo TAMD 63p's 370hp each. I'm interested in converting the shaft drive to pod drives for a multitude of reasons. I first would like to know more about these Zues drives and woulsd really appreciate any constuctive input as well as any source of information that is available. Thanks to any & all that are willing to help out. Kevin

Welcome Kevin,

for which reason would you change the system?

And what might "Zues" be???

Merc. Zeus? Do you have the tunnels required?

If not (sure you do´nt have them), Volvo IPS would be the only choice.

But again, why?

Regards
Richard

[Dash]

Thanks Richard, I am talking about the Zues drives that Cummins Mercruiser are using, It is my understanding that ZF is manufacturing these drives. It is also my understanding that these units can be mated to any Diesel engine within the HP rating of the drive. The increased fuel efieceintcy and increased speed are certainly inviting. I don't have the tunnels on my boat ( but I am pretty handy; I've never built a Rocket ship but I seriously doubt that most boat manufacturers have either) so that part seems a like a little problem. The tunnels are apealing to me because we live & operate in an area that at times has a lot of drift ( Wood , Fishing web etc. ) according to what i've been able to read so far, there would certainly be less to tear apart under the boat if I got rid of the shaft, struts, props & rudders & replace them with a couple of pods that are at there lowest point are even with the keel. There are several other reasons including ease of manuvering ( on the grounds in open water in heavy currents) , Trailerability ( all but imposible with current configuration) just to mention a couple. Kevin

Redesigning the hull, and building tunnels is far away from being a "easy" task, you know?
Though I understand that pods attract you.

Regards
Richard

[Dash]

Thanks for your input Richard, I guess maybe I'm looking in the wrong area for actual info on this type of drive. Was really hoping that there might be someone on this forum that either has first hand knowledge of the pros & cons through ownership or is very well versed through information gathered. I'm really lookinf for actual information (not an argument over my or anyone elses abilities or inteligence level) Thanks Kevin

Ah, ja,

who was posting arguments about your intelligence level?

And do you respect a boatbuilders knowledge and opinion, and call it valid?

Redesigning your hull to accommodate these Merc. Zeus pods is way more than getting the axe and the resin out and start doing it!

Regards
Richard

[Stumble]

Dash I spoke with volvo about using their IPX drives on my boat, and was told that the application of the system to the boat has to be designed into the boat from the start. To truly operate at their best they change many of the requirements of the design process, and that they are not sutable for retrofit, at least not without major redisign and rebuilding of the boat. In my case it would have cost more to refit to these than to buy another boat.

That being said, at least the Volvo drives are servicable at any Volvo Marine dealer, and replacement parts are fully distributed through their repair system.

I would also be concerned about the claim that the drives are supposed to be mounted in a tunnel. Sure it could be done, but I am curious about the ability of the pods to turn while constrained by a tunnel. To me it would mean either that the tunnels would have to be very large compared to a standard prop tunnel, or that the drives have limited turning radius. Either way it seems like an issue.

Well,

here you have the tunnels:

http://www.cmdmarine.com/prop/zeusover.html

...and of course the idea has nothing in common with sense!

Regards
Richard

[powerabout]

Most installs I have seen are not in tunnels and that includes boats built for them.
I think its just a bit of hype re less draft to sell the idea.

As to relying on a a Merc dealer versus a volvo dealer/price of parts issue,
no comparison for me.

Both have the single joystick control which is very nice and does a great job of selling them.
( as do the sterndrives)
There has been a few installs in Austrailia that have made the performance and fuel economy of shaft drives look very ordinary.
I think there is going to be much more of these around.

Clearly long term the maintanence must be more than a shaft, one would imagine?
When fuel goes back to usd100+/bbl the fuel versus maintanence argument will clearly change.

[Willallison]

Dash, being alloy the Waverunner would probably be less of an ordeal to alter than if it were FRP. Having said that, the rebuild would still be a monumental job... the engines would almost certainly have to be moved aft, so quite apart from the work involved directly in that, there would be issues surrounding the change in weight distribution. (Though I guess a longer than normal jackshaft could be incorporated)
Not all pod drives are a recipe for increased fuel efficiency and speed. The hull must, as others have suggested, be designed around the propulsion system. In general they tend to have greater volume aft than a traditional shaft installation such as yours.
Quite apart from all that though, there is the question of cost. Being a charter operation, your situation is different to the average weekend boatie, but I'd still be surprised if the numbers stack up. Have you asked ZF how much it would cost for a pair of Zeus drives?
Also, I understand that CMD (and probably ZF as well) like to be involved in the design of the installation - so it would be worth talking directly to them about that too.

Powerabout - I've never heard of a Zeus installation that didn't incorporate tunnels (as opposed to Volvo's IPS units that don't)

[Dash]

Thanks you guys for the constructive thoughts on this subject. Where I oerate, #2 diesel is still $5.35 per gallon. I appreciated the comment about the additional volume of the stern on many of the boats that are using the pod drives. I'll try explane that the engine room in this boat is extremely voluminous. & the engine rails are already to accept the slide back of the engines. As for the tunnels, I am 100% confident that once I've engineered them to work with ZF specs for thier drives, I posses all of the tools & skill level required to get the job done. Again thanks for the comments Kevin

[powerabout]

Do they recommnd them to be in tunnels just to mount the drive vertical or are they scared they might get knocked off and the rotating part thru the hull is way bigger than the IPS who dont seem to care what happens when you hit something?

Anyone got a photo of one that has met a railway sleeper?

CHeck out www.quadzeus.com, hull is very flat and they seem to be very shallow if at all any tunnels?

The zeus comes with a trim tab as they know what happens when you add a tunnel to a planning hull...

So maybe in a cat you wouldnt need the tunnels?

I wonder if pods came first would someone then invent the sterndrive?

Just think where we have been....old omc stern drives rotated the lower unit around the top gear housing so no universal joints required.
It was mounted through the transom with a large bellows and solid to the engine on the stringers..the strong part of the boat.
They then put a hydraulic cylinder under the front of th engine and had trim.
( also had the ball gears so you could tilt it.)
Now build one of those as a duo prop and capable of 600hp diesel and forget about the tilting??
There are some renderings of Volvo doing this in their early prototyping.
Volvo also had the AQ 750 in the past for diesels.

Originally Posted by powerabout

I wonder if pods came first would someone then invent the sterndrive?

Yes of course! Pods are older than sterndrives! (Schottel Antrieb)

And believe us, the Zeus pods NEED tunnels.

[Karl2]

Originally Posted by apex1

Yes of course! Pods are older than sterndrives! (Schottel Antrieb)

And believe us, the Zeus pods NEED tunnels.

Why would the Zeus pod NEED tunnels ?

Karl

[Willallison]

Originally Posted by Karl2

Why would the Zeus pod NEED tunnels ?

Karl

Well, apart from anything else, Zeus is far more than a simple drive unit - it is a complete system, and the tunnels are an integral part of that system. As are the trim tabs that are located within those tunnels etc.