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Discussion Starter #1
Okay long story short I bought a boat that has standard rotation (LH) 351w motor in it. Apparently these boats are supposed to have reverse rotation engines (RH) to counter the weight. So when I'm driving down the lake it torques to the right now.

Anyway I know you can buy reverse cams to fit the motor but has anyone ever done this before? And what would be needed besides a cam, starter, and distributor?
 

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Well, I know what you're talking about, but have no experience with it. I think it would be easier to sell your motor and buy a new one. At the very least, you'll need a new prop. :lol: I'd suspect you need a new oil pump and water pump since the impellers would be backwards as well depending on the type. Probably just easier to hang a new motor than to through all the work.

How come the boat didn't come with the proper motor in the first place?
 

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Well, I know what you're talking about, but have no experience with it. I think it would be easier to sell your motor and buy a new one. At the very least, you'll need a new prop. :lol: I'd suspect you need a new oil pump and water pump since the impellers would be backwards as well depending on the type. Probably just easier to hang a new motor than to through all the work.

How come the boat didn't come with the proper motor in the first place?
Well I have looked its hard to find the motor I need without spending more then the boats worth. And not sure as to why someone put the wrong motor in it. I guess they thought any old 351 or 302 would work.
 

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Why would it matter if the rotation is RH or LH on a single engine boat? Could you give a little info on the boat model, length, etc. Just seems a little odd, but I'm sure there's more to the story. I have a single engine outboard, and rotation is irrelevant.
 

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Why would it matter if the rotation is RH or LH on a single engine boat? Could you give a little info on the boat model, length, etc. Just seems a little odd, but I'm sure there's more to the story. I have a single engine outboard, and rotation is irrelevant.
It has to do with asymmetric thrusting of the prop, or p-factor as its called. Propeller driven aircraft exhibit the same thing. At high angles of attack, one side of the prop makes more thrust than the other side and will cause a turning motion. There is also a paddle wheel effect of the prop chopping through the water that can make it even worse. That's why they invented the counter-rotating outdrives. Depending on the boat, a reverse direction prop can help lessen the effect. Sometimes the skeg will be built with a couple of degrees angled offset to counteract it as well.

Your point is valid though with a properly loaded boat, on trim, with a straight skeg and shouldn't exhibit much pull even with a single rotation prop.
 

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Maybe it's an inboard thing, but on a single outboard it makes no difference

http://www.thehulltruth.com/boating-forum/391507-counter-rotating-vs-standard.html#b
That's not really true. An inboard would actually exhibit less of the problem because the rudder is separate from the drive system. The outboards are more pronounced because the p-factor will steer the motor which in turn steers the boat. You will feel it whenever you have high power settings and the hull is not on plane. If the bow is high, with a lot of power, you'll usually have to fight the turning tendency with some wheel force. It should go away though as the hull levels out.

But you're right in that both directions will produce the same effect, just in different directions. What's interesting in the link you provided is that the reverse rotation is done all internal to the gearbox. That makes sense!

A couple of links:
http://en.wikipedia.org/wiki/Propeller_walk

http://www.tinboats.net/forum/viewtopic.php?f=4&t=25640

http://continuouswave.com/ubb/Forum4/HTML/007742.html
 

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Discussion Starter #8
Why would it matter if the rotation is RH or LH on a single engine boat? Could you give a little info on the boat model, length, etc. Just seems a little odd, but I'm sure there's more to the story. I have a single engine outboard, and rotation is irrelevant.
boat is a 79 ski tique (older smaller version of a ski nautique) they are 16.5 ft long. Skydork pretty much summed up why I have to have a RH rotation engine.
 
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