Propellers

[nedcontact]

Hello,

I am new owner of Wekkender 24 who is driven by 2 engines Volvo AQ130 and sterndrive 270.

I would like to know which type of propeller it is possible to go up but especially, in which direction to mount the propellers.

Currently, the left engine has a contrary propeller with the right engine . However, I think that the engines turn in the same direction?

Why the mechanic has mounted the propellers like that?
Which is the good direction of assembly of the propellers?

Large thank you in advance for all the answers which you will want to give me and I send to you while waiting for my best greetings of France.

[Lars Lundbladh]

The propellers should be mounted with left rotation on portside (left side) and right rotation on starboard (right side). To change rotation shift A and B see picture:



If you change rotation you must also change the propeller from right to left or left ro right.


The two sterndrives should be mounted with a toe-out to avoid cavitation. It should be adjusted to 15-25 mm measured between the two screws holding the trim fin (exhaust outlet) with bigger V-bottom adjust to higher value. Remember to push the drives outwards while measuring the distans.



Regarding the prop size what dimension do you have now?

/Lars

[nedcontact]

Thank you very much for your answer.
You are an excellent interlocutor and a good expert of the Fjords.

My boat is currently equipped:
- 1 propeller Volvo 813316 (LR)
- 1 propeller Volvo 813317 (RR)

I suppose that the propeller mounted on left is reference 813316.

On the other hand, I did not include/understand the adjustment well to make on the sterndrive one and if one could reverse the direction of rotation of the propellers.

Still thank you.
In waiting.
Good day and better friendships.
Marcel

[Lars Lundbladh]

Dear Marcel

The engines always rotate in same direction however with the sterndrives (Aquamatic 270) you can change direction of propeller rotation regardless of motor rotation. This means that you normally on a twin engine installation mount counter rotation of the two propellers. This to avoid propeller forces, in practical this means that the side force that is normally produced by a single propeller is neutralised.

This picture show the shift mechanism on the sterndrive (AQ 270) it is placed under cover on the front side of the drive.


If you shift the lever from A to B (shifting side) you change the rotation from left to right rotation. The drive is totally reversible and it doesn’t matter if you run it forward or backwards. If you change direction you must also control that the reverse/tiltlocking mechanism especially number 3 that push on a lock sleeve so the drive don´t "float" up during reverse. Se the picture below:


You can also read more about the tilt lock here:
http://www.marinemechanic.com/volvo/tilt_lock_1.htm

The propellers you have is 15x13 this looks a bit small in pitch. What is your maximum speed and engine rpm ?



/Lars

[nedcontact]

Dear Lars,
thank you for all this information which I was unaware of completely.

The internet link that you gave me is very interesting and I did not finish consulting it.

Concerning the performances of the boat, I did not test yet because I do not have the boat for a long time.

Which propellers advises to me you to install for a use 70% one to river and 30% one sea?

Still thank you for all this invaluable information.
Good evening.
In waiting of pleasure of reading you.

Marcel

[Lars Lundbladh]

Marcel,

The propellers you have today should according to my calculation only give you a top speed of 20 knots and a possible risk to go over max recommended motor rpm, that is 5100 rpm on AQ130C motor.

A propeller diameter of 15x15 or 15x17 will give you approx a max speed of 30 knots. Normally the best solution is to optimize the propellers for max rpm or maximum -200 rpm at top speed and full power.

/Lars

[nedcontact]

Dear Lars,
thank you for all this information which you had the kindness to give me.
I will analyze all that and I am passioned by the Fjord boats because they are very beautiful in spite of their sometimes advanced age.
If I find the means of sending a photograph of mine to you, I would not fail to do it.
On the other hand, I noted that I was the only member recorded in France and I a little only smell myself!
I saw that there were members in Belgium and it is not far from at home, so that I would try to contact them to exchange our small technical answers.
In waiting it pleasure of reading you, receive all my friendships.
Marcel

[Lars Lundbladh]

Marcel,

Please mail me at lars.lundbladh@fjordclub.com and you will recive adresses to some French Fjord owners

/Lars