Lavezzi 40: Volvo 3-blade folding prop with D1-30?

[Lavezzi40]

I have just installed D2-40 engines and am considering 18x14 propellers, but it would be nice to know what factory size installed with 30 hp engines on other Lavezzi's for comparison. As I understand from my vendor, Volvo’s own propeller calculation program is not suited for catamarans and the sweet spot would be 2800-3000 RPM with both engines running at max.
The old Yanmar brothers (3GM30F) initially had fixed 2-blade 16x13 and I later changed to Kiwi 16,5 pitch 23 deg. and both seemed OK but difficult to compare with a bigger engine since the torque will be some 35-40% higher and gear ratio/RPM is different on the SD 20/130S.
Would be nice to get it right the first time

[colemj]

I am pretty sure they are 17x12 on the D1-30. You might consider Autoprop instead. We have Volvo folders, but I think the Autoprop would work better if I had to do it again.

Mark

[Cotemar]

As colemj said above.
Here is a bit more prop info also.

http://www.cruisersforum.com/forums/...tml#post346448

http://www.cruisersforum.com/forums/...ml#post1244952

[Oliver66]

Hi boy's,

as above:
17x12 on D1-30

here is a photo:

[Lavezzi40]

Thanks for the info

I do agree on Autoprop, ticks out most of the important performance boxes. Although I cannot say I like the look of it… only visible subsea so no problemJ but when you see it demonstrated in forward/astern in a transparent water filled box at exhibitions it’s like poetry ...in motion

But I have decided on the Volvo prop mainly based on good experience from a previous boat I had – good performance and maneuvering (full stop in a boat length from 5-6 kts) and also simple (no delicate internal mechanism that can break down or fail) and secondly I got a very good deal in combination with the new engines. Not to forget! If any warranty issues on the new sail drives I assume Volvo props will make that easier to handle, but this is just my assumption!

The Lipari should be fairly similar to the Lavezzi in weight and underhull shape, it is about 2000 kg heavier than the Mahe’s (mine is +8000 loaded but empty water/fuel tanks) and when all 3 are set up with the same prop 17x12 from factory it may be on the “light” side for the Mahes. I thought maybe the Lavezzi had a smaller prop but then I will stick with the decision and go for 18x14 - then we’ll see if that was wise when spring comes in April and I get it back in water again

[Oliver66]

Hi lavezzi,

You're gonna put 40hp engines on your cat ?
waouh !! it's gonna be a speedboat !!!

[Lavezzi40]

Well…we’ll see Oliver when spring coms in the northern hemisphere and I get it back in water, the engines are already installed, see picture. To call it a speedboat I really think you need to at least triple or quadruple the 2x 40 horsepower L so my reasoning for the step up was to achieve good cruising speed with one engine at low RPM and less noise and also less fuel consumption, but also to have the extra Hp needed when the arctic storms sets in. The extra cost penalty was actually not more than 10 % on the total cost between 40 vs. 30 hp engines so… far too much temptation to ignore.
Ok – add to this - I’m much in favor of the sound of a cultivated 4-cyl Jcompared to an agricultural 3-cyl ..It’s basically the same engines (same bore/stroke and compression - correct me if I’m wrong anyone?) same Perkins base engine with one extra cylinder.

[Toys_with_time]

Originally Posted by Lavezzi40

Thanks for the info

I do agree on Autoprop, ticks out most of the important performance boxes. Although I cannot say I like the look of it… only visible subsea so no problemJ but when you see it demonstrated in forward/astern in a transparent water filled box at exhibitions it’s like poetry ...in motion

But I have decided on the Volvo prop mainly based on good experience from a previous boat I had – good performance and maneuvering (full stop in a boat length from 5-6 kts) and also simple (no delicate internal mechanism that can break down or fail) and secondly I got a very good deal in combination with the new engines. Not to forget! If any warranty issues on the new sail drives I assume Volvo props will make that easier to handle, but this is just my assumption!

The Lipari should be fairly similar to the Lavezzi in weight and underhull shape, it is about 2000 kg heavier than the Mahe’s (mine is +8000 loaded but empty water/fuel tanks) and when all 3 are set up with the same prop 17x12 from factory it may be on the “light” side for the Mahes. I thought maybe the Lavezzi had a smaller prop but then I will stick with the decision and go for 18x14 - then we’ll see if that was wise when spring comes in April and I get it back in water again

I have been really happy with my factory fitted 3 blade folding on DI-30's although regularly have to clean out mollusc sea life from the gears etc. Had 1 mod done by the boat yard in Turkey - they fitted a ring to reduce the space where fishing lines etc always seemed to get caught. They reckon it reduces risk of more serious damage and they fit it to all their charter boats. Part was 35 euros per side.

TwT

[Dod42]

Anyone ever fitted one of the rope cutter things to their props? There seems to be a number of different type. I sail a lot in Morton Bay and it's only a matter of time before I get one of the thousands of crab pots littering the bay.

[colemj]

Originally Posted by Toys_with_time

I have been really happy with my factory fitted 3 blade folding on DI-30's although regularly have to clean out mollusc sea life from the gears etc. Had 1 mod done by the boat yard in Turkey - they fitted a ring to reduce the space where fishing lines etc always seemed to get caught. They reckon it reduces risk of more serious damage and they fit it to all their charter boats. Part was 35 euros per side.

TwT

That spacer ring was supposed to be supplied by Volvo on those drives (it is a standard part). Are you sure it wasn't removed in the past?

Mark

[colemj]

Originally Posted by Dod42

Anyone ever fitted one of the rope cutter things to their props? There seems to be a number of different type. I sail a lot in Morton Bay and it's only a matter of time before I get one of the thousands of crab pots littering the bay.

We have "Strippers" on ours Ambassador Marine - Home of the Stripper Propeller Protector

Mark

[Toys_with_time]

Originally Posted by colemj

That spacer ring was supposed to be supplied by Volvo on those drives (it is a standard part). Are you sure it wasn't removed in the past?

Mark

Props have never been off before and the part was supplied and fitted by a factory authorised repair agent so odd. Will investigate further.

TwT

[Dod42]

Originally Posted by colemj

We have "Strippers" on ours Ambassador Marine - Home of the Stripper Propeller Protector

Mark

They look very nice. I guess the problem is that you will only know if the don't work. I will have a look at fitting something like these when we next haul