Reply
 
Thread Tools Search this Thread
 
Old 31 October 2008, 20:03   #21
Member
 
Country: UK - England
Town: Mighty Penryn
Boat name: Little Joe.
Make: Avon Searider
Length: 4m +
Engine: Honda BF50
Join Date: Aug 2005
Posts: 8,841
Quote:
Originally Posted by Downhilldai View Post
I've heard it all now....
If you run 'em, it'll bollox the gearboxes on both engines. I made that 1100 mistake once. The bearing carriers will only carry load in one direction.
Swapping the props might help.
__________________

__________________
Mollers is offline   Reply With Quote
Old 31 October 2008, 20:18   #22
Member
 
Country: UK - Wales
Town: West Wales
Make: Vipermax 5.8, SR4.7
Length: 5m +
Engine: 150 Opti, F50EFi
Join Date: Sep 2005
Posts: 6,298
Quote:
Originally Posted by Mollers View Post
If you run 'em, it'll bollox the gearboxes on both engines...
Yes - I don't dispute that one bit.

Just can't believe they bought the story from the apprentice who rigged the motors and claimed that they were fitted with those props when they were delivered

Quote:
Originally Posted by Mollers View Post
..I made that 1100 mistake once...
I'm really sorry to hear that

Quote:
Originally Posted by Mollers View Post
Swapping the props might help.
As long as you reverse the gearchange linkages in the control boxes too.
__________________

__________________
Downhilldai is offline   Reply With Quote
Old 01 November 2008, 05:50   #23
Member
 
Country: UK - England
Town: Mighty Penryn
Boat name: Little Joe.
Make: Avon Searider
Length: 4m +
Engine: Honda BF50
Join Date: Aug 2005
Posts: 8,841
Quote:
Originally Posted by Downhilldai View Post

As long as you reverse the gearchange linkages in the control boxes too.
Only if close quarter handling is a concern.
__________________
Mollers is offline   Reply With Quote
Old 05 November 2008, 06:14   #24
Member
 
Country: Australia
Town: adelaide
Boat name: tba
Make: custom
Length: 7m +
Engine: outboard,200+
Join Date: Mar 2008
Posts: 71
On light twin engine aircraft with counter rotating engines that both turn inwards.
the downward moving blade creates more thrust. So when one engine fails, the thrust from the downward moving blade is closer to the centre of the aircraft, reducing the asymetric effect, so less rudder is needed to keep the aircraft going straight.
Not all twins have counter rotating engines.
rm
__________________
r mcdonald is offline   Reply With Quote
Old 05 November 2008, 06:30   #25
exspyrd trayd membir
 
The Garfish's Avatar
 
Country: Ireland
Town: inn wiliks hed
Make: Redbay 6.5
Length: 6m +
Engine: Twin Etec 90hp
Join Date: Aug 2003
Posts: 962
Quote:
Originally Posted by Mollers View Post
Only if close quarter handling is a concern.
inn de troo spirrit ov innvestigativ jornalizm, i an i smels a storey.


spil de beens yew cawnegian nobwangir

garF
__________________
luk arfter numbir wan, downt stepp inn numbir too
The Garfish is offline   Reply With Quote
Old 05 November 2008, 09:23   #26
Member
 
Simon B's Avatar
 
Country: UK - England
Town: Leicester
Boat name: Vixen
Make: Ribcraft
Length: 6m +
Engine: Suzuki OB 175
MMSI: 235071839
Join Date: Jun 2004
Posts: 1,621
Quote:
Originally Posted by r mcdonald View Post
On light twin engine aircraft with counter rotating engines that both turn inwards.
the downward moving blade creates more thrust. So when one engine fails, the thrust from the downward moving blade is closer to the centre of the aircraft, reducing the asymetric effect, so less rudder is needed to keep the aircraft going straight.
Not all twins have counter rotating engines.
rm
Now this answers my earlier question.

Quote:
Originally Posted by BogMonster View Post
By the time the props touch the water on a plane you have usually got bigger problems to worry about
Remind me not to charter aircraft in the Falklands, their views on basic principals appear to be well err...very, very basic!!
__________________
New boat is here, very happy!
Simon
www.luec.org
Simon B is offline   Reply With Quote
Old 05 November 2008, 09:37   #27
RIBnet admin team
 
Nos4r2's Avatar
 
Country: UK - England
Town: The wilds of Wiltshire
Boat name: WhiteNoise/Dominator
Make: Ballistic 7.8/SR5.4
Length: 7m +
Engine: Opti 225/Yam 85
MMSI: 235090687/235055163
Join Date: Jul 2005
Posts: 12,645
RIBase
Quote:
Originally Posted by Simon B View Post
Remind me not to charter aircraft in the Falklands, their views on basic principals appear to be well err...very, very basic!!
Can't knock it for accuracy though
__________________
Need spares,consoles,consumables,hire,training or even a new boat?

Please click HERE and HERE and support our Trade Members.

Join up as a Trade member or Supporter HERE
Nos4r2 is offline   Reply With Quote
Old 05 November 2008, 12:00   #28
Member
 
Simon B's Avatar
 
Country: UK - England
Town: Leicester
Boat name: Vixen
Make: Ribcraft
Length: 6m +
Engine: Suzuki OB 175
MMSI: 235071839
Join Date: Jun 2004
Posts: 1,621
Absolutely not Nos!

I've got a thing about knockers...
__________________
New boat is here, very happy!
Simon
www.luec.org
Simon B is offline   Reply With Quote
Old 05 November 2008, 12:01   #29
Member
 
Country: UK - England
Town: Dorset & Hants
Boat name: Streaker/Orange
Make: Avon/Ribcraft
Length: 4m +
Engine: 50Yam/25 Mariner
Join Date: Apr 2007
Posts: 5,551
I thought that in the light twin ( aircraft) its more to do with airflow hitting one side of the rudder (as it scorkscrews on leaving the porp) & 'pushing' the tail round - some of the older twins if the 'wrong engine' goes on takeoff you are only going one way - down and left , or is that right ?

You can see the effect in water jets - the shaft of water trying turn after leaving the jet.
__________________
PeterM is offline   Reply With Quote
Old 08 November 2008, 07:57   #30
Member
 
Country: Australia
Town: adelaide
Boat name: tba
Make: custom
Length: 7m +
Engine: outboard,200+
Join Date: Mar 2008
Posts: 71
Quote:
Originally Posted by Blackroady View Post
I thought that in the light twin ( aircraft) its more to do with airflow hitting one side of the rudder (as it scorkscrews on leaving the porp) & 'pushing' the tail round - some of the older twins if the 'wrong engine' goes on takeoff you are only going one way - down and left , or is that right ?

You can see the effect in water jets - the shaft of water trying turn after leaving the jet.
If both engines turn in the same direction, if the engine that fails is the one that is turning towards the the fuslage. The engine that is still operating and producing alot more thrust on the downward moving blade is further from the centre line of the aircraft, it will need more rudder(and create more drag) to keep the plane staight. so climb performace will not be as good due to more drag.
On single engine aircraft, the prop wash does hit the vertical stabilizer and rudder on one side more than the other. So at high power settings(take off, climbing) right rudder is needed to keep the aircraft staight.
some light twins will not climb very well (or at all)at full weight on a hot day
regards
rm
__________________

__________________
r mcdonald is offline   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not 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 Off
Pingbacks are Off
Refbacks are Off





Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -5. The time now is 02:02.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.