Cummins/Merc Zeus Drive

Fishtigua

Fishtigua

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A mate in the US has a weird problem. This is not a pish take nor a plonker-puller.

In his marina, when there is very high water after the thaw/high rainfall, the Corps of Army Engineers release a lot of water from the Dam. That means 3 to 4 knots of water is gushing through the docks for weeks. Day after day of force on the lines and his sterngear.

The question is - Do the bloody props spin for days and days in this state. I have no chuffin' idea. Will it damage the bearings or seals? Who the heck could plan for this?

Yes, yes. I have my old chum Pete McCullar on speed-dial but £ to a penny, I bet even he wouldn't have a clue.

Over to you lot for a guess.
 
Ah, as thought, do Volvo/Merc outdrives also suffer the same kinda stress?

I live in the Channel Islands, but our marinas do not have that much flow. I think the word is' Flow,' spinning gear up.

On classic yachts and schooners, we lock the tiny shafts off, 'cos the sails are more powerful than a poxy 40 year old Perkins.

Just a thunk.
 
With conventional shaft drive the worry is the shaft seal if needs water +ve lubrication/ cooling .Obviously with nothing running there’s zero supply as the props spin in the current .
Additionally …….
Putting in in gear risks winding up the box with zero to min oil pressure , and furthermore zero water cooling as the main water pump impeller is not turning risking oil overheating , thats why they have either shaft locks or indeed g box locks like my disc .They can stand a bit like marina manoeuvres free wheeling , but not “ weeks and “ weeks “ spinning away .

Your mates predicament .
Would have thought slightly similar with Zeus / VP IPS in the sense zero g box oil pressure and with constant turning props ( from the current 24/7 , the shaft oil seals will eventually end up compromised some what .Ie a tendency for water ingress if this is allowed for “ weeks “ and “ weeks “
When the engine is running I think the idea is to have a grater oil pressure inside the pod behind the seals than say 1 or 1.5 M below the surface sea water pressure so‘s should eventually a rubber or whst ever material seal go ( they will have an end of life ) the Dir of travel of fluids ie the oil is out .Not water getting sucked in .

Fear is emulsified oil in the pod I guess .

Plus zero cooling going off as the main motor water pumps through any heat exchanger is not functioning.

Not familiar with the pod electrotwackery surrounding the interlocking , if they could be locked in gear switched off with dead motors while the boats unattended? Wether you can switch them off in gear without a orchestral alarm and buzzer performance reverberating around the marina from the dash ?
 
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I’ve had a boat with Cummins engines and Zeus drives for 12 years. (Brilliant set up!) I may be wrong but I would be surprised if the props would spin on a few knots of current. To be certain have you spoken to a dealer and asked the question?
 
I think bruce on here has had similar issues with his outdrives because he moors his boat on a fast flowing river. Think his seals wore out in double quick time because the props were turning 24 hours a day. Dont know what his fix was though.

It cant be a new problem though, there must be loads of boats in the marina where your mate is with the same problem.

I suppose locking the props with a block of wood wedged between prop and skeg is a non starter because you cant easily get to the props?

I guess in the absence of anything else I'd be tempted to leave it in gear, but not sure if you can do that with zeus pods.
 
@julians I bet they are hydraulic boxes, so even on manual sticks (which obviously it aint got!) in gear means nothing as there's no engine running to built up pressure on the gbox pump to lock disks to crank, which anyway would be pointless as engine would be running...

@Moonstruck I'd hope they would spin else resistance within the box would be significant.
 
vas said:
@julians I bet they are hydraulic boxes, so even on manual sticks (which obviously it aint got!) in gear means nothing as there's no engine running to built up pressure on the gbox pump to lock disks to crank, which anyway would be pointless as engine would be running...

@Moonstruck I'd hope they would spin else resistance within the box would be significant.
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I am thinking of the times I have been under the boat whilst it is out of the water, cleaning the props. They are not at all easy to move hence my thoughts that I would be surprised if they moved with a few knots of current.
 
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