SailDrive or Shaft

[Gludy]

I have a choice on my new boat of saildrive or shaft drive.
They will be 75HP turbo Yanamar based on the 59hp standard engine.

I am struggling to see any advantage with shaft drive over saildrive - just more opportunity for vibration etc ..... so I have opted for SailDrive - am I wrong?

[boris]

shaft drives are simpler cheap (mantance) and more reliable. the reason sail drives are so popular is ease of installation (saves the manufacter money)

[Nordic cat]

Saildrives offer less vibration and noise, but are more complicated to maintain like you need to lift out the boat to change the oil. Less hassle with alignment compared to a shaft.

I have chosen saildrives but will not use their water inlets that can tend to clog in certain conditions, so will have a seperate through hull for cooling water instead. I would rather have had shaft drives, but due to the space available, and gearboxes it has ended up with drives.

Shafts are more robust, so it's the usual with boats, a compromise you have to make and learn to live with.

Cheers

Alan

P.S. I would choose naturally aspirated engines, less things to break and easier to fix.

Check out the generators (230V AC) that Yanmar offers, They fit between the engine and gearbox and give up to 6kVA power. I will have these on each engine, just 3 kVA each though. Saves buying and maintaining a seperate generator and only adds 31 kg/engine for 3 kVA.

[Gludy]

You have to have the boat out of the water to change the oil??? Do you mean the gearbox oil?

Shafts always have alignment problems - there is more to go wrong ancause vibration. I have always had shafts to date and had universal joints etc etc but there was always some vibration.

I would like to know more about how sail drives are maintained.

[Nordic cat]

Originally Posted by Gludy

You have to have the boat out of the water to change the oil??? Do you mean the gearbox oil?

Shafts always have alignment problems - there is more to go wrong ancause vibration. I have always had shafts to date and had universal joints etc etc but there was always some vibration.

I would like to know more about how sail drives are maintained.

Sorry if my post was not clear, YES, you need to have the boat out to change the oil in the drive, unless you know a few tricks, and have some hoses, plugs, and can dive/hold your breath for a reasonable time....

Pick your problem... alignment/vibration issues, oil change issues, protection issues. stern gland or not..

Alan

[GordMay]

I think Practical Sailor did a fairly good job of analyzing the pro & cons.

Maintaining Your Saildrive - Saildrive Pros and Cons
by Mike Muessel
Practical Sailor Advisor: Maintaining Your Saildrive

See also:

Pros and Cons of a Saildrive?
http://www.cruisersforum.com/forums/...rive-4669.html

Saildrive versus shaftdrive ~ by Andrew Norton
Saildrive versus shaftdrive – Boat Reviews, Tests & News - BoatPoint Australia

[Eleven]

The old Prout cats have a drive leg that lifts clear of the water. Not very efficient apparently but they give no drag once lifted, props can be cleared from the cockpit, and they steer 30 deg each side too which helps manouevring.
With Yanmar drive and the generator mention above they have many advantages.
No major issues like props fouling, blades falling off, shaft vibration etc etc.
Depends how much motoring you do normally.
And if you want to consider water driven generators while sailing.

[bmartinsen]

I don't know about Yanmar but my 25 year old boat has a volvo saildrive. I recently
replaced the engine and saildrive (because of engine). I like the unit.

You do NOT have to haul boat to change oil.
No vibration
No noticeable Prop Walk. Backing up is easy.
Sits well protected behind keel.
Rubber seal recommended replacement 7yrs. Costs about $300us thats not bad compared to other maintanance- bottom paint ,oil & filter chances etc.

I have never had a problem with cooling water, the unit has ports on either side of leg like an outboard but also has one at the very bottom but having an extra thru hull available is a good ( boy scout) idea. I have been in harbours where after 2 weeks
both A/C and refigeration cooling has plugged up with sea critters but engine was fine?

On the down side, when the boat yard puts the strap under the leg and lifts the boat, motor mounts and rubber seal don't hold 9 tons well. Still didn't leak! Watch out for electrolsis, keep zinc fresh. I haven't had this problem but have met others. Don't paint leg with copper bottom paint- fast death.
Good Luck

[Eleven]

GordMay post No6 gives great advice from users.
As usual for Gordmays links. When does he find time to go sailing?

[GordMay]

Originally Posted by Eleven

GordMay ... When does he find time to go sailing?

He has time, but he doesn't even own a boat anymore!

[Tellie]

Originally Posted by GordMay

He has time, but he doesn't even own a boat anymore!

I've realized far too late that the best way of boat ownership is to have a friend that owns one.

[GordMay]

Originally Posted by Tellie

I've realized far too late that the best way of boat ownership is to have a friend that owns one.

Notwithstanding the fact that I have no friends, I'm not fond of sailing on other people's boats.
I'm scuppered.

[rtbates]

here's Volvo's new IPS drive.
World Debut! Volvo-Penta's NEW IPS 750/850 - YachtForums.Com

Hopefully they'll discover a need to make smaller units that can pivot.

[fastcat435]

Originally Posted by Gludy

I have a choice on my new boat of saildrive or shaft drive.
They will be 75HP turbo Yanamar based on the 59hp standard engine.

I am struggling to see any advantage with shaft drive over saildrive - just more opportunity for vibration etc ..... so I have opted for SailDrive - am I wrong?

I have the yanmar 75 hp turbo with Gori 3 blade overdrive props on my 48 and get 10 knots out of her flat out or 2 knots better than the 54 hp . If I where to choose again I would take
shaft drives , less maintenance ease of changing the anodes , no lifting out of the water for oil changes etc etc
The advantage of using sail drives is for the builder , less time consuming but a lot more maintenance.

Greetings

Gideon

[Troutbridge]

Gideon, the manual for my Volvo sail drive does not require the boat to be lifted out for oil changes. They recommend regular inspections (fair enough, I do that when I check the engine oil & have a general look around the engine compartments). The seals need replacing every seven years or on condition. Anode replacement is no more difficult than with shaft drive. I agree that there is potentially more maintenance with saildrive, but if they failed on a regular basis no builder would get away with using them.