Reply
 
LinkBack Thread Tools Search this Thread Display Modes
  #1   Report Post  
posted to rec.boats
external usenet poster
 
First recorded activity by BoatBanter: Sep 2008
Posts: 2,326
Default Outdrive torque...

I've already admitted that I don't have a lot of experience with
outdrives, but I ran into something this morning with the Pro Line
that was fixed that may, or may not, be imagination.

I took the boat up to Webster Lake this morning to run it up for a
prospective buyer. Everything seems to work ok - boat is running
fine,nothing seems amiss, but I noticed something odd - or at least I
think it's odd.

When you cram the throttle for a hole shot, the boat rotates slightly
to starboard along it's bow/stern axis - almost like the torgue roll
you get with a high horsepower car. At least it feels like that to me
- it's not a violent movement by any means, but it feels funky.

It that normal? Just asking - I've never "felt" this before on other
outdrive boats I've tested or driven.
  #2   Report Post  
posted to rec.boats
external usenet poster
 
First recorded activity by BoatBanter: Sep 2009
Posts: 463
Default Outdrive torque...

On Fri, 25 Sep 2009 08:18:30 -0400, Tom Francis - SWSports
wrote:

I've already admitted that I don't have a lot of experience with
outdrives, but I ran into something this morning with the Pro Line
that was fixed that may, or may not, be imagination.

I took the boat up to Webster Lake this morning to run it up for a
prospective buyer. Everything seems to work ok - boat is running
fine,nothing seems amiss, but I noticed something odd - or at least I
think it's odd.

When you cram the throttle for a hole shot, the boat rotates slightly
to starboard along it's bow/stern axis - almost like the torgue roll
you get with a high horsepower car. At least it feels like that to me
- it's not a violent movement by any means, but it feels funky.

It that normal? Just asking - I've never "felt" this before on other
outdrive boats I've tested or driven.


What year is this Pro LIne? Mine was a 1997 model 211 cuddy. I don't
recall anything like you're mentioning, but I don't recall ever
cramming the throttle either. Did you try this with different trim
settings?
--

John H
  #3   Report Post  
posted to rec.boats
RG RG is offline
external usenet poster
 
First recorded activity by BoatBanter: Jul 2006
Posts: 438
Default Outdrive torque...


"Tom Francis - SWSports" wrote in
message news
I've already admitted that I don't have a lot of experience with
outdrives, but I ran into something this morning with the Pro Line
that was fixed that may, or may not, be imagination.

I took the boat up to Webster Lake this morning to run it up for a
prospective buyer. Everything seems to work ok - boat is running
fine,nothing seems amiss, but I noticed something odd - or at least I
think it's odd.

When you cram the throttle for a hole shot, the boat rotates slightly
to starboard along it's bow/stern axis - almost like the torgue roll
you get with a high horsepower car. At least it feels like that to me
- it's not a violent movement by any means, but it feels funky.

It that normal? Just asking - I've never "felt" this before on other
outdrive boats I've tested or driven.


Newton's Third Law of Motion. Your analogy to a torque roll in a high
horsepower car is applicable. In this case, since the boat is resting in
water versus the car on land, the boat is naturally more tender and will
exhibit Newton's Third Law by way of a reaction to torque being applied to
the longitudinal axis with less input (torque) than was required for the
car. This phenomena is one of the reasons counter-rotating propellers were
invented for torpedoes and ultimately for outdrives. If that boat had a
Bravo 3 drive instead of an Alpha drive, you couldn't get it to rotate on
the longitudinal no matter how hard you stuffed the go stick.



  #4   Report Post  
posted to rec.boats
Jim Jim is offline
external usenet poster
 
First recorded activity by BoatBanter: Sep 2009
Posts: 483
Default Outdrive torque...

Tom Francis - SWSports wrote:
I've already admitted that I don't have a lot of experience with
outdrives, but I ran into something this morning with the Pro Line
that was fixed that may, or may not, be imagination.

I took the boat up to Webster Lake this morning to run it up for a
prospective buyer. Everything seems to work ok - boat is running
fine,nothing seems amiss, but I noticed something odd - or at least I
think it's odd.

When you cram the throttle for a hole shot, the boat rotates slightly
to starboard along it's bow/stern axis - almost like the torgue roll
you get with a high horsepower car. At least it feels like that to me
- it's not a violent movement by any means, but it feels funky.

It that normal? Just asking - I've never "felt" this before on other
outdrive boats I've tested or driven.


It's called torque steer. In the olden days there was an fin anode above
the prop that could be adjusted to minimize that effect. More modern
setups use a flat plate anode in place of the fin. I couldn't tell you why.
  #5   Report Post  
posted to rec.boats
external usenet poster
 
First recorded activity by BoatBanter: Sep 2009
Posts: 463
Default Outdrive torque...

On Fri, 25 Sep 2009 10:23:47 -0400, Jim wrote:

Tom Francis - SWSports wrote:
I've already admitted that I don't have a lot of experience with
outdrives, but I ran into something this morning with the Pro Line
that was fixed that may, or may not, be imagination.

I took the boat up to Webster Lake this morning to run it up for a
prospective buyer. Everything seems to work ok - boat is running
fine,nothing seems amiss, but I noticed something odd - or at least I
think it's odd.

When you cram the throttle for a hole shot, the boat rotates slightly
to starboard along it's bow/stern axis - almost like the torgue roll
you get with a high horsepower car. At least it feels like that to me
- it's not a violent movement by any means, but it feels funky.

It that normal? Just asking - I've never "felt" this before on other
outdrive boats I've tested or driven.


It's called torque steer. In the olden days there was an fin anode above
the prop that could be adjusted to minimize that effect. More modern
setups use a flat plate anode in place of the fin. I couldn't tell you why.


And this may be why I don't recall the experience with my ProLine.
--

John H


  #6   Report Post  
posted to rec.boats
external usenet poster
 
First recorded activity by BoatBanter: Sep 2009
Posts: 27
Default Outdrive torque...

Jim wrote:
Tom Francis - SWSports wrote:
I've already admitted that I don't have a lot of experience with
outdrives, but I ran into something this morning with the Pro Line
that was fixed that may, or may not, be imagination.

I took the boat up to Webster Lake this morning to run it up for a
prospective buyer. Everything seems to work ok - boat is running
fine,nothing seems amiss, but I noticed something odd - or at least I
think it's odd.

When you cram the throttle for a hole shot, the boat rotates slightly
to starboard along it's bow/stern axis - almost like the torgue roll
you get with a high horsepower car. At least it feels like that to me
- it's not a violent movement by any means, but it feels funky.

It that normal? Just asking - I've never "felt" this before on other
outdrive boats I've tested or driven.


It's called torque steer. In the olden days there was an fin anode above
the prop that could be adjusted to minimize that effect. More modern
setups use a flat plate anode in place of the fin. I couldn't tell you why.


Some still do. It must have to do with no-feedback/hydraulic steering
on large OB's.
  #7   Report Post  
posted to rec.boats
external usenet poster
 
First recorded activity by BoatBanter: Aug 2007
Posts: 30
Default Outdrive torque...

On Sep 25, 7:23�am, Jim wrote:
Tom Francis - SWSports wrote:





I've already admitted that I don't have a lot of experience with
outdrives, but I ran into something this morning with the Pro Line
that was fixed that may, or may not, be imagination.


I took the boat up to Webster Lake this morning to run it up for a
prospective buyer. �Everything seems to work ok - boat is running
fine,nothing seems amiss, but I noticed something odd - or at least I
think it's odd.


When you cram the throttle for a hole shot, the boat rotates slightly
to starboard along it's bow/stern axis - almost like the torgue roll
you get with a high horsepower car. �At least it feels like that to me
- it's not a violent movement by any means, but it feels funky.


It that normal? �Just asking - I've never "felt" this before on other
outdrive boats I've tested or driven. �


It's called torque steer. In the olden days there was an fin anode above
the prop that could be adjusted to minimize that effect. More modern
setups use a flat plate anode in place of the fin. I couldn't tell you why.- Hide quoted text -

- Show quoted text -


Actually, outdrives still use the fin type annode if not equipped with
power steering. The fin was adjustable side to side to minimize the
boats tendency to follow the rotation of the prop...fighting that all
day is tiring. With power steering it isn't a factor.
Mike
  #8   Report Post  
posted to rec.boats
external usenet poster
 
First recorded activity by BoatBanter: Jul 2006
Posts: 10,492
Default Outdrive torque...

On Fri, 25 Sep 2009 08:18:30 -0400, Tom Francis - SWSports
wrote:

When you cram the throttle for a hole shot, the boat rotates slightly
to starboard along it's bow/stern axis - almost like the torgue roll
you get with a high horsepower car. At least it feels like that to me
- it's not a violent movement by any means, but it feels funky.

It that normal? Just asking - I've never "felt" this before on other
outdrive boats I've tested or driven.


It depends on the weight of the boat, amount of deadrise, trim, etc,
not all that unusual in my also limited experience. It's one of the
reasons for the dual counter-rotating props on the Bravo 3.

  #9   Report Post  
posted to rec.boats
external usenet poster
 
First recorded activity by BoatBanter: Sep 2008
Posts: 2,326
Default Outdrive torque...

On Fri, 25 Sep 2009 08:18:30 -0400, Tom Francis - SWSports
wrote:

Hey - thanks guys - I thought I was imagining it.

Heh - must not be as old as I thought. :)
  #10   Report Post  
posted to rec.boats
Tim Tim is offline
external usenet poster
 
First recorded activity by BoatBanter: Nov 2006
Posts: 19,107
Default Outdrive torque...

On Sep 25, 4:35*pm, Tom Francis - SWSports
wrote:
On Fri, 25 Sep 2009 08:18:30 -0400, Tom Francis - SWSports

wrote:

Hey - thanks guys - I thought I was imagining it.

Heh - must not be as old as I thought. *:)


No Tom, youre still sane.

My Marquis is a heavy old tub with a 350 GM and Alpha 1, and it takes
a lot of throttle to get it on plane, and yes, it will tip the boat
starboard (not badly) untill the tub gets up a little.

Normal nature of the beast

all is normal.


Reply
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules

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


Similar Threads
Thread Thread Starter Forum Replies Last Post
25 hp merc torque steer Dixon General 5 July 10th 07 05:24 PM
What's Difference Between Inch-Pound Torque and Feet-Pound Torque? [email protected] General 16 October 18th 06 04:30 PM
Torque for manifolds Dave General 1 November 7th 05 02:07 PM
Attaching an engine to an outdrive with a torque tube. Bruce Taber Boat Building 5 September 15th 04 01:07 PM
torque dowra ASA 18 January 23rd 04 03:23 PM


All times are GMT +1. The time now is 11:47 AM.

Powered by vBulletin® Copyright ©2000 - 2025, Jelsoft Enterprises Ltd.
Copyright ©2004-2025 BoatBanter.com.
The comments are property of their posters.
 

About Us

"It's about Boats"

 

Copyright © 2017