Counter Rotation Direction

[SJFE]

Attention Twin drive guys: I need some advice here. I have them set up right now turing inboard. What is the standerd and why?
Thank's in advance .
Tom G

[ReddyWatts]

L-CW R-CCW was about 5 mph faster than the L-CCW R-CW, but this turned a lot easier.

[shockerman80]

agrees. they dont turn worth beans the R ccw and the L cw but dang does it help out with the speed.

[SJFE]

Ok guys so then the way I have it now L-CW R-CcW aka turing inboard is the ticket correct?

[shockerman80]

yes sir that is correct.

[SJFE]

No thank you guy's. Now I'm off to assemble some CR drive cables.

[Mich. Maniac]

Isnt it weird that if you take a left wound prop shaft you cant just turn it around to make it a right wound shaft? Kinda like a threaded shaft. just something I noticed the other day. yes im weird

[Eyekandyboats]

no you cant how ?

BTW on our big skater we run then inward. workes the best

[robby76]

inward is best. like reddy stated...5 mph faster. i tested it on my big sea terror after i had set it up. changed it to outwards and struggled bad.

also, read on some forum, not here, that hypotheticly inboard sets some kind of balance out in front of hull and outboard brings it in behind center of hull. something to keep in mind on not blowing over.

as for left lay and right lay flex cable, i use the correct cable. keep in mind that the CW turning cable will act like a water pump and bring on water into the hull so a good piece of silicone tubing here on stuffing tube to cable will help alot.

found it. TORQUE

[Mich. Maniac]

a good piece of silicone tubing here on stuffing tube to cable will help alot.

Good question SJFE, I am wondering as robby said help alot. I want completely dry hull since a recent motor change was sacrificed from another boat. My question is has anyone run counter props with CW cable? I know the originall way is best and why try to chance it but I wonder if anyone has un-spun a flex shaft by running it backwards?

[G Doggett]

You must use the correct cable to suit the rotation direction.
A fellow club member accidently used CW cable on a conventional CCW set up in a DV and as Robby has said it acted like a pump pulling water up the shaft into the boat even with a seal at the top end.

I haven't had a chance to gps my twin jolly but it does seem a little faster with the props spinning inwards.
I would really like to know the theory to explain this.
Graham.

[Dr. Jet]

L-CW R-CCW was about 5 mph faster than the L-CCW R-CW, but this turned a lot easier.

Now this is a fascinating and timely discussion. I'm about to put a twin-motor Micro Scat Cat on the water and I understand why L=CCW, R=CW would turn better (propwalk would want to settle a sponson that was out of the water). What does not make a whole lot of sense is why one rotational arrangement would be noticibly faster than the other unless it has something to do with the interaction of thrust cones.

I expect the Micro Cat to be a bit over-powered, so I may initially use the arrangement that provides better turning at the cost of top speed for the first few runs. I'm using 0.030" wire drives so switching rotational directions is a no-brainer.

[Stealth Assassin]

I can tell you why... Spinning Inwards creates more bow lift. Spinning outwards creates more transom lift.

[G Doggett]

I can tell you why... Spinning Inwards creates more bow lift. Spinning outwards creates more transom lift.

WHY ? HOW ????

Please explain.

Graham.

[Stealth Assassin]

It Is very hard for me to explain here...