Shuggy
Well-Known Member
I was wondering if the forum had any experience of hydraulic drives? In short, we need a new engine to replace a 42 year old Perkins 4107 that has seen better days.
The boat is a Nicholson 43 (see attached drawing) with a forward-facing engine and gearbox, sloping down at about 15-17 degrees. The shaft drives a Walter V drive, which directs the shaft back towards the stern gland. I've attached a photo of the set-up too: white shaft comes out of engine/gearbox and into green V drive in foreground. V drive shaft then powers lower prop shaft - stern gland can be seen below white shaft.
She used to be fitted with a hydraulic drive: pump was attached to the engine, while the hydraulic motor was attached to a short prop shaft (we think). I have been on another Nicholson 43 with this set-up. The V drive we have now is undersized for the asthmatic 4107 so will not suit a more powerful engine.
Solution 1: replace the engine and gearbox with a modern engine and gearbox (Beta 43 is currently the favoured candidate) and keep the existing V-drive. Pros: relatively easy. Cons: Engine angle is marginal for the Beta (so I understand). V drive is at risk of failure, which could be messy.
Solution 2: replace the engine and gearbox with a bobtail Beta 43 (i.e., engine only) and use the engine output shaft to drive a modern Walter remote V drive in place of the current one. The new one is a combined V-drive and gearbox here (scroll down for 'remote mounted models). Pros: neat solution. Cons: Expensive, shifts mass forwards, difficult to align properly.
Solution 3: replace the engine, gearbox and V drive with a modern hydraulic drive. Not sure about the pros and cons of this but I'm hoping that the weight distribution could be kept roughly the same, and alignment would be easier. There is room to re-instate the hydraulic tank, so that's not a problem. Yes, there are transmission losses. But with 43HP, would we care? We probably only have about 30HP left in the Perkins and we can still get 6kts with a clean bottom and that's about all I want to be able to do.
Our bilge is very, very deep so it is unlikely that the hydraulic motor would become submerged (if it does, that's the least of our problems!) and therefore suffer from massive corrosion.
Does anyone have experience of modern hydraulic drives?
Is there a solution that I am missing? (Other than saildrive, which I'm not going to consider as I do not want to alter the underwater profile.)
Has anyone faced the same challenge?
(I do not plan to keep the current engine, so getting a re-build is not an option I really want to consider, before anyone suggests one. Reason? We've had 2 failures this year and I have a young family. Sailing is all we do for our holidays, so we need a reliable engine. I've had enough of sailing onto moorings for one season!)
Thanks in advance for any help.
The boat is a Nicholson 43 (see attached drawing) with a forward-facing engine and gearbox, sloping down at about 15-17 degrees. The shaft drives a Walter V drive, which directs the shaft back towards the stern gland. I've attached a photo of the set-up too: white shaft comes out of engine/gearbox and into green V drive in foreground. V drive shaft then powers lower prop shaft - stern gland can be seen below white shaft.
She used to be fitted with a hydraulic drive: pump was attached to the engine, while the hydraulic motor was attached to a short prop shaft (we think). I have been on another Nicholson 43 with this set-up. The V drive we have now is undersized for the asthmatic 4107 so will not suit a more powerful engine.
Solution 1: replace the engine and gearbox with a modern engine and gearbox (Beta 43 is currently the favoured candidate) and keep the existing V-drive. Pros: relatively easy. Cons: Engine angle is marginal for the Beta (so I understand). V drive is at risk of failure, which could be messy.
Solution 2: replace the engine and gearbox with a bobtail Beta 43 (i.e., engine only) and use the engine output shaft to drive a modern Walter remote V drive in place of the current one. The new one is a combined V-drive and gearbox here (scroll down for 'remote mounted models). Pros: neat solution. Cons: Expensive, shifts mass forwards, difficult to align properly.
Solution 3: replace the engine, gearbox and V drive with a modern hydraulic drive. Not sure about the pros and cons of this but I'm hoping that the weight distribution could be kept roughly the same, and alignment would be easier. There is room to re-instate the hydraulic tank, so that's not a problem. Yes, there are transmission losses. But with 43HP, would we care? We probably only have about 30HP left in the Perkins and we can still get 6kts with a clean bottom and that's about all I want to be able to do.
Our bilge is very, very deep so it is unlikely that the hydraulic motor would become submerged (if it does, that's the least of our problems!) and therefore suffer from massive corrosion.
Does anyone have experience of modern hydraulic drives?
Is there a solution that I am missing? (Other than saildrive, which I'm not going to consider as I do not want to alter the underwater profile.)
Has anyone faced the same challenge?
(I do not plan to keep the current engine, so getting a re-build is not an option I really want to consider, before anyone suggests one. Reason? We've had 2 failures this year and I have a young family. Sailing is all we do for our holidays, so we need a reliable engine. I've had enough of sailing onto moorings for one season!)
Thanks in advance for any help.
