Beta / Volvo S110 drive

[kernowd]

Hi yachties
Has anyone out there had experience fitting a new Beta Marine inboard to an existing Volvo 110s sail drive leg?

I have an ancient MD11C and the leg seems pretty mint.
Just wondering how well the combination of old and new would work together.............

Beta offer this set up and it all looks good on paper.

 

[scottie]

Look at the cost of a bob tailed engine against cost of new complete unit and then check the cost of a drive on its own and that will give you an answer.

The 110 saildrive is an old unit and whilst maybe looks mint it is likely to be reaching its sell by date.

The 110 is no longer built and any replacement would require alterations to fit.

MD11 will have top revs of 2400 what is beta output.

110 will have some resale value

So you could save a little but end up with a new engine fitted to a 20-30 year old drive that is not quite right still require new prop and diaphragm £400 for both so I suspect there is not really a logical choice if you add reale value of the boat.

 

[kernowd]

Cheers Scottie
My local yard have offered me a very sweet deal on a Beta25SD package with custom mounts to fit my Volvo bed.

There will be a running MD11C sail drive for sale soon!

 

[Guy M]

Hi yachties
Has anyone out there had experience fitting a new Beta Marine inboard to an existing Volvo 110s sail drive leg?

I have an ancient MD11C and the leg seems pretty mint.
Just wondering how well the combination of old and new would work together.............

Beta offer this set up and it all looks good on paper.

Hi, did you end up going through with this? I'm considering the same.

 

[Tranona]

Are you thinking of re-using the 110 drive? As suggested in post#2 not a good idea partly because of the age, but also it probably has a 1.68:1 reduction for the old slower revving engines and the newer style of higher revving diesels need a larger reduction ratio, usually 2.2:1 or 2.4:1 depending on the engine.

If you are replacing the complete engine and drive then a Volvo is probably a better bet. Whether you choose Beta or Volvo you will have to modify the bed as the forward mounts are in a different place.

 

[Guy M]

Are you thinking of re-using the 110 drive? As suggested in post#2 not a good idea partly because of the age, but also it probably has a 1.68:1 reduction for the old slower revving engines and the newer style of higher revving diesels need a larger reduction ratio, usually 2.2:1 or 2.4:1 depending on the engine.

If you are replacing the complete engine and drive then a Volvo is probably a better bet. Whether you choose Beta or Volvo you will have to modify the bed as the forward mounts are in a different place.

Hi Tranona
Thanks for response.
Yes, I was aware of the different reduction ratios. I phoned BETA UK today. They argue that to replace my old md7a I need the 20HP Beta. This means that at 2600 rpm I'll still be hitting about 14HP with my 110.
The bed is actually OK but the feet will be tailored.

 

[Tranona]

You can't run it at 2600rpm. You have to prop it to achieve close to its rated speed of 3600rpm.. Beta use a 2:1 ratio which gives a shaft speed of 1800rpm. Some 110s have a 1.68:1 which gives a shaft speed 0f 2142rpm so you won't be able to fit one of their standard props (usually 15*9 2 blade) but a smaller probably 13" if one is available.. Your current shaft speed is 1548 if the engine is rated at 2600rpm (some sources say 3000rpm).

However this is putting the cart before the horse. The starting point for calculating what is best starts with boat, not what engine it has in it at the moment. Many older boats are underpowered because the choice was poor - often a suitable size engine was physically too big to fit in the hull shapes that were common then.

What boat is it. With the basic data from a source such as Sailboatdata it id easy to calculate what hp you need to achieve hull speed and from there what combination of engine/gearbox/prop will do this. If you like i can do this for you using one of the computer programmes.

Although I have a Beta engine in my current boat (newly installed) I have a lot of experience with saildrives, both Volvos and Yanmars and if it were my choice I would not fit a Beta saildrive complete, although attaching one of their engines to a Volvo drive is sound..... except your 110 is over 40 years old and if it has a sub optimum ratio - that is you won't be able to get the correct size propeller it is better to consider a complete Volvo or Yanmar package.

 

[Guy M]

Thanks! My boat is not on sailboatdata. It's weatherly Ruffian, 8.5m LOA, approx 8m water line, 2.5 m beam, 1.63m draft. Est 3300kg

 

[Tranona]

OK. 3300kgs sounds a bit heavy for a sporty boat like that (if it is anything like its 23' sister) but 16hp would comfortably give you hull speed. 20 is OTT. The problem stays the same though if you want to re-use the 110 drive and it is 1.68 you can't get a small enough prop to make it work. The calculations show a 12*6 and the smallest fixed 2 blade is a 14*7 and folder 13*7

You don't say what your budget is but the lowest cost is likely to be changing to a secondhand 120 drive with a 2,47:1 and a Beta 16. The going rate for a 120 drive is around £1k, but there is always the risk attached to a 30 year old bit of kit. They are however pretty robust and a 16hp is at the bottom of the power range. The prop for that would be a 14*9. If you go completely new then the choice is between Volvo D1 13 which is a bit short on power but should perform at least as well as your current engine or a Yanmar 15. A Volvo D1 20 is also a possibility if you re looking for the best motoring performance as this will give between half and a knot of extra top speed. You don't say what your current prop size is but the combination of a Beta 16 and a 120 drive would give a similar shaft speed to your existing set up for which a 14*9 or 15*8 would be suitable.

I would think a Volvo would be easiest to fit as I believe the diaphragm is the same although the mounts will need to be modified.

Hope this helps