reverse rotation on 351w - Kawasaki ZX-10R.net
 
LinkBack Thread Tools Display Modes
post #1 of 8 Old 08-17-2012, 10:40 PM Thread Starter
Squid
 
dconner08's Avatar
 
Join Date: Oct 2011
Location: Salisbury
Posts: 34
Posting Frequency
  
reverse rotation on 351w

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?
dconner08 is offline  
Sponsored Links
Advertisement
 
post #2 of 8 Old 08-18-2012, 08:06 AM
REPOST Enforcement Mod
 
SkyDork's Avatar
 
Join Date: Feb 2006
Location: Wesley Chapel, FL
Posts: 13,500
Posting Frequency
           
Garage
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. 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?

I may not be perfect, but at least I don't ride a Suzuki.

Ridding the Internet of bad grammar, 1 post at a time.
#WordCrimes




SkyDork is offline  
post #3 of 8 Old 08-19-2012, 02:58 PM Thread Starter
Squid
 
dconner08's Avatar
 
Join Date: Oct 2011
Location: Salisbury
Posts: 34
Posting Frequency
  
Quote:
Originally Posted by SkyDork View Post
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. 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.
dconner08 is offline  
post #4 of 8 Old 08-20-2012, 09:16 PM
GP Rider
 
cuhuba's Avatar
 
Join Date: Mar 2008
Location: MIAMI
Posts: 1,318
Posting Frequency
        
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.

Ride like you pay a mortgage...
cuhuba is offline  
post #5 of 8 Old 08-20-2012, 09:52 PM
REPOST Enforcement Mod
 
SkyDork's Avatar
 
Join Date: Feb 2006
Location: Wesley Chapel, FL
Posts: 13,500
Posting Frequency
           
Garage
Quote:
Originally Posted by cuhuba View Post
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.

I may not be perfect, but at least I don't ride a Suzuki.

Ridding the Internet of bad grammar, 1 post at a time.
#WordCrimes




SkyDork is offline  
post #6 of 8 Old 08-20-2012, 10:26 PM
GP Rider
 
cuhuba's Avatar
 
Join Date: Mar 2008
Location: MIAMI
Posts: 1,318
Posting Frequency
        
Maybe it's an inboard thing, but on a single outboard it makes no difference

http://www.thehulltruth.com/boating-...tandard.html#b

Ride like you pay a mortgage...
cuhuba is offline  
post #7 of 8 Old 08-21-2012, 07:44 AM
REPOST Enforcement Mod
 
SkyDork's Avatar
 
Join Date: Feb 2006
Location: Wesley Chapel, FL
Posts: 13,500
Posting Frequency
           
Garage
Quote:
Originally Posted by cuhuba View Post
Maybe it's an inboard thing, but on a single outboard it makes no difference

http://www.thehulltruth.com/boating-...tandard.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

I may not be perfect, but at least I don't ride a Suzuki.

Ridding the Internet of bad grammar, 1 post at a time.
#WordCrimes




SkyDork is offline  
post #8 of 8 Old 08-21-2012, 11:32 PM Thread Starter
Squid
 
dconner08's Avatar
 
Join Date: Oct 2011
Location: Salisbury
Posts: 34
Posting Frequency
  
Quote:
Originally Posted by cuhuba View Post
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.
dconner08 is offline  
Sponsored Links
Advertisement
 
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Kawasaki ZX-10R.net forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in











Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Similar Threads
Thread Thread Starter Forum Replies Last Post
Gen 4: rear wheel rotation sensor robhzx10r The ZX-10R 3 05-28-2012 08:49 PM
Tire Rotation Question/Help jmsmith37 Performance and Tech 24 01-28-2009 04:36 PM
Std vs. Reverse Shifting afskypilot Performance and Tech 16 12-28-2007 06:49 AM
Rotation indicator led Balbo Pictures and Videos 15 04-13-2007 11:02 PM
Front Sprocket Rotation NC-NINJA Performance and Tech 17 07-29-2005 12:33 AM

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome