Replacing an engine: your thoughts on what unit to choose?

[Tranona]

I replaced an MD7A with a Nanni and was delighted. We’ve got a Beta now but it’s no better or worse than any of the alternatives. Imho. The OP needs to assess all the variables. It might very well be that a modern Volvo Penta sail drive will be a much simpler fit. The hole in the hull for the sail drive leg is critical.

That is the big plus for replacing with a Volvo as you get the very latest saildrive which will allow a wide choice of propellers and can be fitted with a rope cutter. However Beta do 2 saildrive packages, the first a complete unit which will be a direct replacement with special mounting feet to fit on the Volvo bed, or a bobtail engine and adaptor to fit an existing Volvo drive. The latter is of course cheaper but it means using an obsolete 30+ year old drive.. The OPs boat displaces 3000kgs so is a bit heavy for a 13hp and would definitely benefit from a 20hp .

 

[ChromeDome]

If diligent about #2, your options and consequences ($$) of decisions will become clear, I'm sure.

It will presumably make the project easier to plan,- there certainly is no shortage of ideas for the original question "thoughts on what unit to choose?"

 

[Beneteau381]

After much aggravation and more money than I like to think about having been thrown at it over the last few years, the very old Volvo MD7A on my boat (an Allan Wright designed Nova 28) has finally been condemned. The Volvo agents here in New Zealand have recommended repowering with another Volvo unit, the D1 - 13 or 20 HP unit. I have also been looking at the Beta 14 SD motor. Does anyone have any thoughts/experience on these units, or other suggestions? It's a 28-foot yacht, clean design underwater, and the MD7's 12.5 HP seemed to push it along quite adequately. The old saildrive would probably also be too worn-out to fit to the new unit but might have some value as salvage. Is it worth fitting a folding prop at the same time? Needless to say, the whole exercise is going to cost more than the boat is worth, except that without a working engine, a boat is just an expensive hunk of fibreglass occupying an expensive hole in the water. Oh well, that's sailing, I guess!

Beta supply the unit complete with instruments gearbox etc, so take away the box and they also I believe supply a converter for the sail drive. So I suggest you contact them?

 

[masterofnone]

After much aggravation and more money than I like to think about having been thrown at it over the last few years, the very old Volvo MD7A on my boat (an Allan Wright designed Nova 28) has finally been condemned. The Volvo agents here in New Zealand have recommended repowering with another Volvo unit, the D1 - 13 or 20 HP unit. I have also been looking at the Beta 14 SD motor. Does anyone have any thoughts/experience on these units, or other suggestions? It's a 28-foot yacht, clean design underwater, and the MD7's 12.5 HP seemed to push it along quite adequately. The old saildrive would probably also be too worn-out to fit to the new unit but might have some value as salvage. Is it worth fitting a folding prop at the same time? Needless to say, the whole exercise is going to cost more than the boat is worth, except that without a working engine, a boat is just an expensive hunk of fibreglass occupying an expensive hole in the water. Oh well, that's sailing, I guess!

When I replaced my Vetus 56hp circa 1986, I discovered that the new Vetus engines, had identical dimensions to the original. Much to my surprise. The answer was therefore, the one that fits without too many mods. If I had bitten the bullet 10 yrs ago it would have saved me a small fortune in repair costs.

 

[LittleSister]

The OPs boat displaces 3000kgs so is a bit heavy for a 13hp and would definitely benefit from a 20hp .

If going down the Beta route, there is the Beta 16 (16hp, twin cylinder) between the Beta 14 (13.5hp, twin) and the Beta 20 (20hp, triple).

 

[penfold]

The 16 and 14 are the same engine, IIRC the 14 produces its rated power at lower revs.

 

[LittleSister]

The 16 and 14 are the same engine, IIRC the 14 produces its rated power at lower revs.

No, the 16 is 599cc, whereas the 14 is 479cc.

You are probably thinking of the 14 and the 10, both of which are 479cc, but the 10 is limited to 3,000rpm, whereas the 14 goes to 3,600rpm (as does the 16).

All produce their maximum power at maximum revs.

Linky to Beta engine range brochure - 10 45T HE SB 221 06599 REV14 1121

 

[penfold]

Me culpa! Serves me right for not going to the horse's mouth.

 

[Fossil]

Thanks everyone - some interesting points here. To deal with some of them - as regards fitting an outboard, I have ruled this out as my particular boat has a cutaway transom , which allows easy entry and exit from the water. An outboard would require a bit of a rebuild in this area, so wouldn't be practical. To digress for a moment, the yacht I had before the current one was a nineteen-foot Dancer that some optimist had fitted a 15HP Yamaha outboard to. It went very well under power (he had used it for fishing, mostly) but didn't sail all that well as the weight so far aft unbalanced it. Secondly, I well take the point that ongoing availability of spares and service is going to be critical, particularly in Wellington, which is off the beaten track in NZ yachting terms. Also I take the point that compatibility with the existing bearers and saildrive hole will be important, together with cost and availability of all the other items. Oh well, back to the drawing board!

 

[ChromeDome]

It would seem that there are two dealers/workshops in Wellington announcing themselves as Volvo and Yanmar suppliers.
Maybe interested in taking your old lump in exchange?

A brief call would help you decide if they should be shortlisted.

TS Marine
Strait Marine | authorised dealer of Yanmar, Mercury and Cummins Onan Generators

 

[MikeCC]

One consideration i don't think I saw mentioned is that if you put in different saildrive you will almost certainly have the expense of a new GRP bed. If the current Volvo saildrives fit the existing bed that's likely to be least pain route. Is there any reason not to look at used engines in better condition than current?

 

[oldmanofthehills]

One consideration i don't think I saw mentioned is that if you put in different saildrive you will almost certainly have the expense of a new GRP bed. If the current Volvo saildrives fit the existing bed that's likely to be least pain route. Is there any reason not to look at used engines in better condition than current?

I would council against an outboard option anyway due to security and fuel costs perhaps 2 or 3 times an inboard if petrol or excess weight and cost if diesel. Got the teeshirt there and it cause issues

Beta or others can certainly make fittings to suit your bearer as can any semicapable steel fabricator - just as long there is enough space

As others have reminded Beta spares as basically Kubota except for heat exchanger

My experience on second hand or refurbishment is that I wasted valuable cash or if I did work myself I wasted my time and often sailing time. Best of luck

 

[eebygum]

I looked at doing something on my 1973 S&S SHE32C with its old Yanmar YSE12; which is only a single pot 12hp.

I created a spreadsheet and it's amazing what all the extra costs were to the actual engine.....new prop, propshaft, engine bearers modified, fuel tank and hoses, new hull fitting for larger sized water intake, new fuel and water filters; which together with just a reconditioned engine would be more than I paid for the boat (and that's with me doing all the work).

I ended up having a marine engineer give it a detailed once over, we tweaked the fuel governor; installed a after-market new starter motor and 5 years and many thousand miles it's still going strong.

My advice therefore would be to try and fix/repair and keep sailing !

 

[nestawayboats]

Nobody has mentioned electric option, so I will... But in the interests of clarity, I should also point out it's something we sell. I'd also further point out that I've actually done it to my own yacht, and have two seasons actual experience using it - this is not conjecture. It won't suit everybody, but if you could make it work for you it's worth consideration...

The concensus seems to be a new diesel would be somewhere in the £6-10,000 range, plus fitting if not DIY. And on an old boat you'd probably want to replace the diesel tank etc while you're at it, on top of that.

At current Epropulsion prices - the range with which I'm most familiar - £7000 will buy you a 6kW pod motor, 9kWh battery, mains charger etc. On my boat - a 4 tonne Sadler 29 - I have an Epropulsion Pod 6 and 2x 9kWh batteries (ie 18kWh capacity), total cost around £11000. Now lots of people will say 6kW can't be enough for a 4 tonne boat... but I'm actually using that system and it seems to be every bit as effective as the Bukh 20 it replaced. In fact I only ever use more than 3kW in short bursts astern, and "crusing speed" say 4.5 knots is 2kW or less. 1kW gets us nearly 4 knots in flat water with a clean bottom. Part of this is electric motors have more torque at low revs so you can use a very different propeller. On a pod that propeller is vertical, not angled (ie less efficient) as it would be on a shaft drive. And very few people run their diesels at full power very often, mainly because it's so unpleasant but also because they find the last few hundred revs doesn't actually make them go much if at all faster whilst using a lot more fuel.

It's much much nicer to use of course. Quiet, smooth, no fumes in the cockpit when motoring downwind. When mooring up you have better control, you don't have to clunk in and out of gear at idle speed (you can apply just 25W if you want). And light airs electric motor sailing - a very efficient way of using a small amount of motor input when you can control it with accuracy - is a revelation. 150W gives us half a knot and points her up a few degrees, whilst being undetectable... to the delight of those on board and the bemusement of those around us!

It is roughly weight neutral compared to what it replaced, but to be fair the Bukh was particularly heavy. Being a pod motor the motor part is outside the boat, and the batteries are where the engine used to be, so we gained cockpit locker space (where the diesel tank used to be). You get rid of a seacock, there's no water inlet for cooling. We haven't yet, but the next logical step is to bin the gas system and use some of our (perhaps further increased) electric capacity for cooking too.

Range, well we have about 60nm at 4 knots if it's flat calm. We could motor across the Channel if we actually had to, particularly bearing in mind we wouldn't have set off in a flat calm, even if then becalmed some percentage of the way across. We easily have room, if we wanted it, to increase that capacity/range by 50%, ie add one more battery. If there's any wind at all we electric motorsail, and it is a sailing boat so if there's a bit more wind we just sail. Of course the range plummets if you try to do more than 5 knots (ie getting towards hull speed) under power, but short bursts of 3kW (remembering we have 6 available) gets us through almost everything eg Portsmouth harbour entrance. It's probably not going to work if you always motor unless it's a F4 beam reach. And it probably won't work if you completely ignore the tides in favour of getting up late.... there are few more inefficient uses of energy in a sailing boat than motoring against a 3 knot tide, but you become more aware of it when you have batteries rather than a tank of diesel.

Charging, there are lots of options but mostly we're actually using it a bit like... a small diesel tank! Most of the charging comes from plugging in to shorepower. This may be too much of a compromise for some, occasionally we have to choose our destination based on finding power. But weekend sailing round the Solent I often don't charge until we've made 3 or 4 weekends use, and I find if I'm aboard 4 days or more I want a marina sometimes anyway (showers etc). There are lots of other options for recharging.

We hear "it's the future" all the time. And indeed better batteries would make it even more viable, the motors are already perfectly viable. But an entirely electric system is already viable for the way a lot of people sail, if you accept its limitations and embrace its advantages.

Ian, Nestaway Boats Ltd

 

[oldmanofthehills]

Nobody has mentioned electric option, so I will... But in the interests of clarity, I should also point out it's something we sell. I'd also further point out that I've actually done it to my own yacht, and have two seasons actual experience using it - this is not conjecture. It won't suit everybody, but if you could make it work for you it's worth consideration...

The concensus seems to be a new diesel would be somewhere in the £6-10,000 range, plus fitting if not DIY. And on an old boat you'd probably want to replace the diesel tank etc while you're at it, on top of that.

At current Epropulsion prices - the range with which I'm most familiar - £7000 will buy you a 6kW pod motor, 9kWh battery, mains charger etc. On my boat - a 4 tonne Sadler 29 - I have an Epropulsion Pod 6 and 2x 9kWh batteries (ie 18kWh capacity), total cost around £11000. Now lots of people will say 6kW can't be enough for a 4 tonne boat... but I'm actually using that system and it seems to be every bit as effective as the Bukh 20 it replaced. In fact I only ever use more than 3kW in short bursts astern, and "crusing speed" say 4.5 knots is 2kW or less. 1kW gets us nearly 4 knots in flat water with a clean bottom. Part of this is electric motors have more torque at low revs so you can use a very different propeller. On a pod that propeller is vertical, not angled (ie less efficient) as it would be on a shaft drive. And very few people run their diesels at full power very often, mainly because it's so unpleasant but also because they find the last few hundred revs doesn't actually make them go much if at all faster whilst using a lot more fuel.

It's much much nicer to use of course. Quiet, smooth, no fumes in the cockpit when motoring downwind. When mooring up you have better control, you don't have to clunk in and out of gear at idle speed (you can apply just 25W if you want). And light airs electric motor sailing - a very efficient way of using a small amount of motor input when you can control it with accuracy - is a revelation. 150W gives us half a knot and points her up a few degrees, whilst being undetectable... to the delight of those on board and the bemusement of those around us!

It is roughly weight neutral compared to what it replaced, but to be fair the Bukh was particularly heavy. Being a pod motor the motor part is outside the boat, and the batteries are where the engine used to be, so we gained cockpit locker space (where the diesel tank used to be). You get rid of a seacock, there's no water inlet for cooling. We haven't yet, but the next logical step is to bin the gas system and use some of our (perhaps further increased) electric capacity for cooking too.

Range, well we have about 60nm at 4 knots if it's flat calm. We could motor across the Channel if we actually had to, particularly bearing in mind we wouldn't have set off in a flat calm, even if then becalmed some percentage of the way across. We easily have room, if we wanted it, to increase that capacity/range by 50%, ie add one more battery. If there's any wind at all we electric motorsail, and it is a sailing boat so if there's a bit more wind we just sail. Of course the range plummets if you try to do more than 5 knots (ie getting towards hull speed) under power, but short bursts of 3kW (remembering we have 6 available) gets us through almost everything eg Portsmouth harbour entrance. It's probably not going to work if you always motor unless it's a F4 beam reach. And it probably won't work if you completely ignore the tides in favour of getting up late.... there are few more inefficient uses of energy in a sailing boat than motoring against a 3 knot tide, but you become more aware of it when you have batteries rather than a tank of diesel.

Charging, there are lots of options but mostly we're actually using it a bit like... a small diesel tank! Most of the charging comes from plugging in to shorepower. This may be too much of a compromise for some, occasionally we have to choose our destination based on finding power. But weekend sailing round the Solent I often don't charge until we've made 3 or 4 weekends use, and I find if I'm aboard 4 days or more I want a marina sometimes anyway (showers etc). There are lots of other options for recharging.

We hear "it's the future" all the time. And indeed better batteries would make it even more viable, the motors are already perfectly viable. But an entirely electric system is already viable for the way a lot of people sail, if you accept its limitations and embrace its advantages.

Ian, Nestaway Boats Ltd

Interesting if in Solent type situation with no long distant cruising with marina mooring each night

down in south cornwall, brittany is 130 miles away for us and padstow a bit further so pleased my 20gallon tank gives nearly 360mile range if winds wrong, plus of course the spare fuel cans extra 140 miles so we fueled in Newlyn Cornwall then refueled in Belfast in Northern Ireland. A 60 mile range would not even enable an irish sea crossing under power if winds change to adverse

My understanding was that NZ offered miles and miles of cruising even more than UK but sparse facilities, so unless the OP only daysails from a marina, electric wont suit

 

[Tranona]

Electric has its place if you can live with the speed and range limitations as described in post#34. However for the OPs boat a straight replacement with a modern saildrive would be the simplest and cheapest. The UK retail for a Volvo D1 13 with drive is around £7k and needs minimal changes to fit the bed where the MD7A is fitted. perhaps £1k for labour and maybe a new prop. A Beta 16 with a Technodrive saildrive would be similar money. A new exhaust might be necessary, but a 40 year old system is probably past it anyway.

 

[penfold]

Interesting if in Solent type situation with no long distant cruising with marina mooring each night

down in south cornwall, brittany is 130 miles away for us and padstow a bit further so pleased my 20gallon tank gives nearly 360mile range if winds wrong, plus of course the spare fuel cans extra 140 miles so we fueled in Newlyn Cornwall then refueled in Belfast in Northern Ireland. A 60 mile range would not even enable an irish sea crossing under power if winds change to adverse

My understanding was that NZ offered miles and miles of cruising even more than UK but sparse facilities, so unless the OP only daysails from a marina, electric wont suit

How often are those distances done in one voyage though? I've done ferry trips between Ireland and Scotland for yachting events, longest distance being ~150 miles, rarely will there be no time under sail and only once did we have to motor the whole way due to no wind. Regardless of wind or no wind, those distances in coastal pilotage are no fun, only undertaken to get the boat where it needs to be and contingency allowed for(i.e. +24hrs for weather diversion, mechanical failure, etc). Cruising is a different kettle of fish, most people like to stop for the night. South of Ardnamurchan you could cruise the west coast of Scotland with an electric auxiliary as described without difficulty. North of there marina berths are fewer and farther between, but with planning it could be done.

 

[Tranona]

How often are those distances done in one voyage though? I've done ferry trips between Ireland and Scotland for yachting events, longest distance being ~150 miles, rarely will there be no time under sail and only once did we have to motor the whole way due to no wind. Regardless of wind or no wind, those distances in coastal pilotage are no fun, only undertaken to get the boat where it needs to be and contingency allowed for(i.e. +24hrs for weather diversion, mechanical failure, etc). Cruising is a different kettle of fish, most people like to stop for the night. South of Ardnamurchan you could cruise the west coast of Scotland with an electric auxiliary as described without difficulty. North of there marina berths are fewer and farther between, but with planning it could be done.

Just as I suggested - if you can live with the speed and range restrictions then OK. BUT read post 34 again. Speed 4knots in flat water, range 60 miles, cost of drive and batteries alone without installation £11k. Compared (with the Sadler 29) of a Beta 25, installed of £9k. Cruising speed 5.5 knots, maximum 6.8 knots, range with 60L tank at cruising speed of 220 miles plus another 70 miles from your spare 20l can. In reality even coastal port hopping you become a slave to shorepower as it is the only way of getting a supply of power.

In our neck of the woods (south coast) cruising plans are dominated by tides, a succession of headlands with tidal gates and certainty of at least one way against the prevailing wind. Or a 60-80 mile cross tide passage to the "continent". Cruising horizons are expanded by having a reliable, powerful engine and a range under power that keeps you independent of shoreside facilities. I have lived with the sort of limitations that electric power has - heavy old boat with Stuart Turner engine. 4.5 knots, 60 mile range on a tank of petrol and know how limiting it is.

 

[penfold]

Ah, the P55! I have suffered the fumes of a Stuart Turner and the complete lack of propulsion due to poor carburation, non-magnetoing magneto, or knackered plugs. Good riddance.

 

[Tranona]

Ah, the P55! I have suffered the fumes of a Stuart Turner and the complete lack of propulsion due to poor carburation, non-magnetoing magneto, or knackered plugs. Good riddance.

My then labrador would agree with you. Did not approve of me starting it by hand, nor the swearing as yet again it fouled the plugs at the most awkward moment. Having said that it did the full cross channel more than once and I have photos of the original owner with a row of jerry cans of petrol on the aft deck to fuel a 25 hour run from Cork to Salcombe.

The replacement Yanmar was slightly faster but with the advantage of working when I wanted it to do rather than when it felt like it.

Happy days.