Direction of propeller rotation - LH or RH pitch

[Greebo]

My motor manual (Volvo Penta I/O) says "a left hand rotating propeller should be selected for single installation since with this direction of rotation there is less tendancy for the boat to list and veer. With a twin installation, the port drive should be adjusted for a left-hand rotaing propeller and the starboard drive for a right-hand rotaing propeller". Yet, it appears to me that the 'standard' rotaion is RH, and there a very few LH props around. Certainly, when I look to buy a prop, there a far more RH than LH props available.
I have been using (and have just brought) a LH prop for my single installation I/O thinking this was correct, now I'm starting to wonder.
Am I right, or is the manual a misprint?
Or does it really matter?
Or do propellers rotate in a different direction here in the southern hemisphere than in the north like our whirlpools when we pull the bath plug are in a different direction? LOL.
I'm confused. Can anyone help please?

 

[Bondo]

Re: Direction of propeller rotation - LH or RH pitch

or is the manual a misprint?

Ayuh,... That's My guess...

 

[Don S]

Re: Direction of propeller rotation - LH or RH pitch

Volvo's cam be run either direction. I have seen many that were changed from LH rotation to RH rotation because it was easier to find props.
The instructions for changine the rotation is printed on a decal inside the back cover of the drive.
Best thing to do is start it up put it in gear and see which direction it turns.

 

[smokeonthewater]

Re: Direction of propeller rotation - LH or RH pitch

Don his question was not about the mechanics of his drive but rather was about the dynamics of how lh or rh rotation affects the handling of his boat

 

[steelespike]

Re: Direction of propeller rotation - LH or RH pitch

Assuming standard boat construction prop rotation should not affect handling
listing etc. Many boats are setup for standard rotation RH. So LH rotation might affect the handling adversly on such a boat.If a boat was setup balanced Then changing rotation would simply reverse the torque affects of the prop.

 

[Greebo]

Re: Direction of propeller rotation - LH or RH pitch

I guess the only real answer is for me to try a RH prop and see what happens. I know it is easy to change the rotation direction of the leg, but I suppose the quickest way is to simply use 'reverse' for 'forward' on my control when I try it out. If there are are no adverse effects then I will change the rotation in the leg.
Regards
Peter

 

[Dhadley]

Re: Direction of propeller rotation - LH or RH pitch

You may not get full throttle with the control in reverse. Depends on how the control itself is constructed.

Every once in a while we run across a boat running a counter rotating set up without the owner realizing it. All theories aside, it may not make any difference. Depends on balance, hull design etc. Should be interesting, let us know.

 

[Silvertip]

Re: Direction of propeller rotation - LH or RH pitch

Using reverse and forward on the control box to experiment with RH and LH props may not and probably will not work since in reverse many control boxes limit the amount of throttle throw. The reason for that is to avoid swamping the boat by going full throttle in reverse.