Same rotation sense of propellers...Can you help me?

[David125]

Hello there
My boat has 2 Ford 2704 ET diesel engines. The bad thing is that the 2 propellers has the same sense of rotation, and the boat runs going to right. It possibile to find an "inverter" (I don't know the exact term) to make one of two props runs in the opposite sense?
they are a bit old engines, and I don't know who can I ask...

thank you for the attention!

 

[volvopaul]

Hi do you have a Ranger 36, these had this problem.
If you have borgwarner boxes your stuck as changing the prop and placing the gearbox in reverse with damage the box later on in life, only way round it is to fit a twin disc, prm or zf hurth type gearbox got to be an inline type though.

 

[David125]

any info about prices and "how can I take" this stuff?

thank you

 

[omega2]

Our engines go the same way as well as the gearboxes are direct 1/1, borg warners, but the boat runs true even without the auto pilot, may be you could trim it out with tabs on the rudders or a slight bias to the right on them as per outboard trim tabs. Do not have any knowledge of your boat but we have a keel on our Aquabell.

 

[David125]

[ QUOTE ]
Our engines go the same way as well as the gearboxes are direct 1/1, borg warners, but the boat runs true even without the auto pilot, may be you could trim it out with tabs on the rudders or a slight bias to the right on them as per outboard trim tabs. Do not have any knowledge of your boat but we have a keel on our Aquabell.

[/ QUOTE ]

I've tried to "trim" the right rudder but it's not enough to cancel the props effect, and in this way it works like a "brake" for the boat /forums/images/graemlins/frown.gif

 

[volvopaul]

Try Lancing maine for parts 01273410025 or mermaid marine dont have there no sorry.

To fit the prm you have to lower the engine by 1.5 inches as its an inline box, you may have to cut the sump as well, done all this twice now for broom monarch owner some years back.
mermaid supplied all the parts then but you can buy from prm direct there in Coventry and get the rest made up.

 

[omega2]

what I was suggesting are small trim tabs pointing the same way as the bias ala outdrives, these do work.

 

[MapisM]

[ QUOTE ]
the boat runs going to right

[/ QUOTE ]
What do you mean exactly?
Sounds unbelievable that you can't keep a straight course, even with both props spinning the same way.
And are they right or left?

 

[andyball]

A friend ran a sea school for years with a Nelson which had same-direction props - Never any complaints from the students. I helmed her once briefly - seemed just fine.

 

[ms1]

Being really dumb here ..... Do gearboxes know the difference between forward and reverse. Is it possibe change the cabling to have one gearbox running forward, one reverse and have a LH and a RHanded prop ?

 

[omega2]

Yes if they are Borg Warner velvet drives, 1 to 1's cos in forward they are what it says on the tin but in reverse they 1: 1.5, or something like.

 

[Dave_Seager]

It should be possible to run straight with your configuration. After all, if not all single-engined boats would be going round in circles.

 

[PCUK]

What make are the gearboxes? And what are the reduction ratios, Many boxes can run in either direction - not Borg Warner.
You could change one box to give contra-rotation, you want them turning outwards - port prop' anti-clockwise starboard prop' clockwise.