Prop for Bav Ocean 38 cc

[1simon]

HI  All,

I have lost the prop (  or somebody stole it) on my Bavaria Ocean 38.
It has a Volvo MD22L with a saildrive 120S.

Apparently , originally it had a 3blade, fixed pitch 16 x 11 Lh prop, but then was changed by the previous owner to 3blade fixed pitch 17 x 13 prop.

I  do not know why the prop size was changed.

Would appreciate any thoughts on the matter in order that I choose the most appropriate prpellor for it now that I have to buy a new one.

Regards

Simon

[Yngmar]

Which revision of the 120S saildrive? They have very different gear ratios.

On our 40 Ocean with MD22L-B and Saildrive 120S-E, the propeller is a 3-bladed 17x15. For other revisions of the saildrive/gearbox the matching propeller would be drastically different though.

Fixed 3-blade aluminium alloy, Volvo (dia x pitch) 17 x 15 L Part No 21381279

[Symphony]

A 16*11 is definitely too small and the 17*13 was probably fitted because the original allowed the engine to reach full revs without reaching maximum boat speed. If that worked - the test is ability to reach maximum hull speed in flat water at just under maximum rated engine RPM then replace with the same size. As Yngmar says there are two different reduction ratios for 120 drives so you need to know exactly which variant you have if you are going to size the prop using one of the programmes such as Propcalc.

[1simon]

Hi  All,

thanks for the feedback.
Its a 120 SE.


Simon

[1simon]

Hi All,

Is there anyone else, who owns a Bavaria Ocean 38,  who can let me know their prop size?

Regards

Simon

[Joe]

Hi Simon,

My 38 Ocean was equipped with a 17x13 3 blade fixed prop and later changed to a 18x12 Volvo 3 blade folding prop.
Max speed is 8.2 kts at 3.100 rpm.

Joe

[1simon]

HI Joe,

Do you  also have an MD 22L and 120S E saildrive?
Were you  happy with 17 x 13 3 bade prop? And did you get better performance with 18x12 prop?

Simon

[Symphony]

There will be little difference between the two with the same type of prop as effectively they are the same size. 1" of diameter is more or less offset by 1" if pitch. In theory the largest diameter is fitted for preference but I don't think Volvo had a prop bigger than 17" at the time even though there is room for larger diameters. As a matter of interest sizing for folding and feathering props is not always the same as the standard fixed prop. My B33 came with a 16*13 2 blade but the folding FlexOfold 2 blade is a 16*11. If you are fitting a standard fixed blade then follow the original. If changing to a folder or feathering take the maker's recommendation.

[Joe]

HI Joe,

Do you  also have an MD 22L and 120S E saildrive?
Were you  happy with 17 x 13 3 bade prop? And did you get better performance with 18x12 prop?

Simon
[/quote


I'm happy with.the performance of the 18x2 folding prop but did not had a chance to try the 17x13 prop as it was on board as a spare part when got the boat. As Symphony said I however can't Imagine that there will be a difference.

Joe