New engine and saildrive

[spottydog]

The engine on my 1986 34’ boat is a VP 2002 with an S120 saildrive, it has always felt a little underpowered.

The engine failed to start this season and following some investigative work it appears to be valve related. I have decided rather than spend money fixing it I am going to fit a new Volvo D1-30 and S130 saildrive.

Will I need a different folding prop to the existing prop on the S120. If so what are the factors that determine the prop size and pitch.
Tia John P.

 

[scottie]

Why are you even asking here where you will get a confusion of opinions
A simple request to the expert manufacturers will get you the answer
If the proper propeller is not fitted you will have wasted so much

 

[spottydog]

Because there are some very knowledgeable and helpful souls still on this forum.

 

[Tranona]

The engine on my 1986 34’ boat is a VP 2002 with an S120 saildrive, it has always felt a little underpowered.

The engine failed to start this season and following some investigative work it appears to be valve related. I have decided rather than spend money fixing it I am going to fit a new Volvo D1-30 and S130 saildrive.

Will I need a different folding prop to the existing prop on the S120. If so what are the factors that determine the prop size and pitch.
Tia John P.

I had a 2015 Bavaria 33. Around 5.5 tonnes and a Flexofold 16*11 2 blade. A 2002 and 120 would probably have a 15*11, but depends on the actual make of the prop. The hubs are normally common so you will need to buy 2 new blades. Suggest you speak to the manufacturer/dealer who will calculate the correct size for you. if it is a FlexoFold then Darglow Engineering are the experts.

 

[spottydog]

I had a 2015 Bavaria 33. Around 5.5 tonnes and a Flexofold 16*11 2 blade. A 2002 and 120 would probably have a 15*11, but depends on the actual make of the prop. The hubs are normally common so you will need to buy 2 new blades. Suggest you speak to the manufacturer/dealer who will calculate the correct size for you. if it is a FlexoFold then Darglow Engineering are the experts.

Thankyou Tranona.
Another basic question how do I measure the size of a 3 bladed folding prop, is it from tip of a blade to the centre of the hub x 2

 

[scottie]

Why are you even asking here where you will get a confusion of opinions
A simple request to the expert manufacturers will get you the answer
If the proper propeller is not fitted you will have wasted so much

Thankyou Tranona.
Another basic question how do I measure the size of a 3 bladed folding prop, is it from tip of a blade to the centre of the hub x 2

A few points to complicate prop selection
Diameter is measured as you say
Worth examining blade for any and all numbers stamped on it
The reduction gear ratio is not same in 120+130 drives and engine revs also different in the two engine series
The max prop diameter is limited by hull clearance
You then have to know whether you want 2 or 3 blade and is main requirement under power or sail
Say again expert more likely to get it correct than an old fart like me on forum and I would be unlikely to pick up tab

 

[Tranona]

Thankyou Tranona.
Another basic question how do I measure the size of a 3 bladed folding prop, is it from tip of a blade to the centre of the hub x 2

Yes, measure like that. Unless your boat is very heavy there is not a lot of benefit from a 3 blade over 2 on that size engine/boat. You don't say what your boat is, but my Bav33 (and previous older 37) are 5.5 tonnes and with the 2 blade easily exceeded hull speed at just under maximum revs and cruised comfortably at around 2200rpm. I actually did quite a bit of testing with different types of props on the 37 and the 2 blade was as good as or better than the others some of which were 3 blade. However if you have a good 3 blade no reason not to keep it but you will need new larger blades to absorb the 50% increase in power. You may find a simple 2 blade cheaper, particularly if you can sell the 3 blade as is. BTW although the reduction ratios are different from the 120 to 130 the maximum engine speeds are also different resulting in the same shaft speed of just under 1500rpm.

If you have a Stripper fitted you will need a new fixed cutter because the pin location is different or a new unit if you change to a 2 blade.

Good luck with the swap. You will appreciate both the extra power and refinement.

 

[spottydog]

Yes, measure like that. Unless your boat is very heavy there is not a lot of benefit from a 3 blade over 2 on that size engine/boat. You don't say what your boat is, but my Bav33 (and previous older 37) are 5.5 tonnes and with the 2 blade easily exceeded hull speed at just under maximum revs and cruised comfortably at around 2200rpm. I actually did quite a bit of testing with different types of props on the 37 and the 2 blade was as good as or better than the others some of which were 3 blade. However if you have a good 3 blade no reason not to keep it but you will need new larger blades to absorb the 50% increase in power. You may find a simple 2 blade cheaper, particularly if you can sell the 3 blade as is. BTW although the reduction ratios are different from the 120 to 130 the maximum engine speeds are also different resulting in the same shaft speed of just under 1500rpm.

If you have a Stripper fitted you will need a new fixed cutter because the pin location is different or a new unit if you change to a 2 blade.

Good luck with the swap. You will appreciate both the extra power and refinement.

Hi Tranona when I started the thread it was in the hope you would see it and respond as I have seen in your previous posts on this subject you are well versed and kind enough to respond in a respectful manner.
I have some knowledge and experience in engine swaps and prop sizing but as it was 15 years since I did the last one I felt it best to assume I have forgotten more than I have retained and ask the very basic questions this seems to have irritated one or two people. You have been very helpful and I do appreciate it.
The boat is an S&S34

 

[Tranona]

Lovely boat and a bit different from my tubby long waterline length Bavaria! Ran the numbers through Vicprop calculator which give hull speed of 6.7 knots needing 20hp so your 2002 (18hp) should make 6.2 or so. The D1 30 will take it close to 7.5 knots. Calculated prop sizes are 16*10 2 blade or 15"10 3 blade. These are based on fixed blade and folders are often different because of the blade designs and different blade areas. Hence rely on the manufacturer or dealer in the final choice..

There is an alternative. If this were a shaft drive the optimum engine would be a Beta 25 as you really don't need the extra of the 30. It is commonly used in similar sized boats like the Fulmar and Sadler 32 that were fitted originally with Bukh 20 or Volvo 2002 like yours but with displacements of 4-5 tonnes were underpowered. This engine can be mated easily to your existing drive with an adaptor kit that Beta supply. You could probably use your existing propeller. There was an article recently in YM describing doing that swap in an HR 34 and it seemed very straightforward. The only reservation is that you will still have a 40 year old drive, but the 120 is very robust and if it is not suffering from corrosion or dirty oil no reason why it should not be re-used. A lower end change of seals and bearings would be wise while it is out of the boat. Substantial saving of about 40% over the Volvo replacement.

Hope this helps

 

[spottydog]

Lovely boat and a bit different from my tubby long waterline length Bavaria! Ran the numbers through Vicprop calculator which give hull speed of 6.7 knots needing 20hp so your 2002 (18hp) should make 6.2 or so. The D1 30 will take it close to 7.5 knots. Calculated prop sizes are 16*10 2 blade or 15"10 3 blade. These are based on fixed blade and folders are often different because of the blade designs and different blade areas. Hence rely on the manufacturer or dealer in the final choice..

There is an alternative. If this were a shaft drive the optimum engine would be a Beta 25 as you really don't need the extra of the 30. It is commonly used in similar sized boats like the Fulmar and Sadler 32 that were fitted originally with Bukh 20 or Volvo 2002 like yours but with displacements of 4-5 tonnes were underpowered. This engine can be mated easily to your existing drive with an adaptor kit that Beta supply. You could probably use your existing propeller. There was an article recently in YM describing doing that swap in an HR 34 and it seemed very straightforward. The only reservation is that you will still have a 40 year old drive, but the 120 is very robust and if it is not suffering from corrosion or dirty oil no reason why it should not be re-used. A lower end change of seals and bearings would be wise while it is out of the boat. Substantial saving of about 40% over the Volvo replacement.

Hope this helps

The boat is a one off designed and built locally from the original S&S34 hull mould. She has a drop keel, cutter rigged on a bowsprit and a deck stepped mast. At the moment it has a 3 blade folding prop 14*? Might stick that on until the end of the season.
I took the engine and saildrive out yesterday the new D1-30 and s130 should arrive early part of next week so I’m going to be busy for a while.
I was going for the Beta originally keeping the S120 but the lead time was too long. Volspec came up with a good deal for the package so went with them.

 

[Tranona]

Good. Pity about the Beta route not working out. The 25 always seems to be in short supply. When I bought my 30 2 years ago they would not quote a delivery date for the 25 and the 30 was over 3 months. Not an issue for me as it gave me time to sell thee old engine while it was still running in the boat.

The current prop will be too small - likely to be 15" as not sure I have seen a 14" 3 blade folder, although haven't seen every make. You probably won't notice much difference at lower speeds except for the high revs for a given speed but you will run out of revs before you get to hull speed. Just be careful with Volvo commissioning as officially they require demonstration that the prop is correct to achieve a maximum of between 3000 and 3200 rpm. They were very particular about that with my new Bavaria as I supplied the propeller to Darglow recommendations and the commissioning engineer made a point of testing it before signing it off.

Hope it all goes well

 

[spottydog]

Good. Pity about the Beta route not working out. The 25 always seems to be in short supply. When I bought my 30 2 years ago they would not quote a delivery date for the 25 and the 30 was over 3 months. Not an issue for me as it gave me time to sell thee old engine while it was still running in the boat.

The current prop will be too small - likely to be 15" as not sure I have seen a 14" 3 blade folder, although haven't seen every make. You probably won't notice much difference at lower speeds except for the high revs for a given speed but you will run out of revs before you get to hull speed. Just be careful with Volvo commissioning as officially they require demonstration that the prop is correct to achieve a maximum of between 3000 and 3200 rpm. They were very particular about that with my new Bavaria as I supplied the propeller to Darglow recommendations and the commissioning engineer made a point of testing it before signing it off.

Hope it all goes well

Ok, the prop is a Volvo, they are a bit confused as their software is telling them I have a engine with gearbox.

 

[Cariadco]

The boat is a one off designed and built locally from the original S&S34 hull mould. She has a drop keel, cutter rigged on a bowsprit and a deck stepped mast. At the moment it has a 3 blade folding prop 14*? Might stick that on until the end of the season.
I took the engine and saildrive out yesterday the new D1-30 and s130 should arrive early part of next week so I’m going to be busy for a while.
I was going for the Beta originally keeping the S120 but the lead time was too long. Volspec came up with a good deal for the package so went with them.

Can I ask who you are buying the new engine from? as I'm toying with a new engine. Thanks.

 

[spottydog]

Can I ask who you are buying the new engine from? as I'm toying with a new engine. Thanks.

Volspec, so far are I am very satisfied with them

 

[scottie]

Lovely boat and a bit different from my tubby long waterline length Bavaria! Ran the numbers through Vicprop calculator which give hull speed of 6.7 knots needing 20hp so your 2002 (18hp) should make 6.2 or so. The D1 30 will take it close to 7.5 knots. Calculated prop sizes are 16*10 2 blade or 15"10 3 blade. These are based on fixed blade and folders are often different because of the

blade designs and different blade areas. Hence rely on the manufacturer or dealer in the final choice..

There is an alternative. If this were a shaft drive the optimum engine would be a Beta 25 as you really don't need the extra of the 30. It is commonly used in similar sized boats like the Fulmar and Sadler 32 that were fitted originally with Bukh 20 or Volvo 2002 like yours but with displacements of 4-5 tonnes were underpowered. This engine can be mated easily to your existing drive with an adaptor kit that Beta supply. You could probably use your existing propeller. There was an article recently in YM describing doing that swap in an HR 34 and it seemed very straightforward. The only reservation is that you will still have a 40 year old drive, but the 120 is very robust and if it is not suffering from corrosion or dirty oil no reason why it should not be re-used. A lower end change of seals and bearings would be wise while it is out of the boat. Substantial saving of about 40% over the Volvo replacement.

Hope this helps

Volvo issued bobtailed engines around that time via dealer’s so not all records were precise

 

[Tranona]

Volvo issued bobtailed engines around that time via dealer’s so not all records were precise

Not sure that is in any way relevant. My Bavaria was new so obviously the engine and drive were fitted at the factory but as I fitted a non standard propeller the commissioning engineer made a point of checking that it met the specification, which it did. Similar with the Beta I have just fitted where we had to change the pitch of the Featherstream because I changed the gearbox type and ratio at the last minute and on first trials it could not meet the minimum revs at WOTT. Not a big deal as it just meant changing the stops in the propeller.

 

[scottie]

Not sure that is in any way relevant. My Bavaria was new so obviously the engine and drive were fitted at the factory but as I fitted a non standard propeller the commissioning engineer made a point of checking that it met the specification, which it did. Similar with the Beta I have just fitted where we had to change the pitch of the Featherstream because I changed the gearbox type and ratio at the last minute and on first trials it could not meet the minimum revs at WOTT. Not a big deal as it just meant changing the stops in the propeller.

Sorry this really only applies to instances to non production slales
Dealers were encouraged to carry a stock engine and shuffle add ons as required such as transmission cooling options etc which was not always correctly recorded as in your case perhaps lt being easier to change rather than rebuild

 

[Tranona]

Sorry this really only applies to instances to non production slales
Dealers were encouraged to carry a stock engine and shuffle add ons as required such as transmission cooling options etc which was not always correctly recorded as in your case perhaps lt being easier to change rather than rebuild

Not sure where you have got all this from. I am not changing or rebuilding anything. Neither is the OP as he has bought a package. You seem to be going back over 10 years when dealers did indeed swap transmissions, but they are notallowed to do that now. With my Beta I did indeed swap from a TMC to a PRM but Beta amended their records at the time the swap was made and before the engine was fitted.

Hope that clears up your confusion.

 

[scottie]

I am not confused or at least do not think so
You obviously recall the period and need no explanation