Reply
 
Thread Tools Search this Thread
 
Old 11 December 2013, 14:41   #1
Member
 
Join Date: Jan 2013
Posts: 195
Setting up Twin Outboards

My winter project is to fit a second Honda 50hp to my 5.5m RIB (just had new tubes).

I have searched for hints and tips but drawn a blank.

Can anyone offer and advice or point me to a useful thread.

I have done this before many years ago and think that things have perhaps moved on a bit.

Questions that spring to mind...
  1. How far apart should the engines be?
  2. At this power I assume they do not need to be counter rotating?
  3. Do I really have to pay upwards of 250 for a tie bar?? (FleaBay)
  4. Will bolting the controls together be straightforward ?(having looked - it looks easy)!
  5. Would you feed engines from separate tanks? This seems sensible to me because I want to maintain a safety margin by having two independant power trains.
    Does anyone know if Honda publish any guide? (can't find one ).

And, just for fun. She currently does 26 knots two up. Any suggestions how fast she'll go when the second 50 is added? (all other things being equal).

I should add at this point that my motivation isn't (just) speed. I want the engines to work a little less hard and really like the safety margin afforded by two engines. Oh - and it will look good! (I know, I know)

Thanks in anticipation

Ian
__________________

__________________
j.i.wilson is offline   Reply With Quote
Old 11 December 2013, 14:58   #2
Member
 
Country: UK - England
Town: Looe
Make: Delta
Length: 4m +
Engine: Mercury
Join Date: Apr 2004
Posts: 1,335
Honda will have a minimum spec size for the distance between the engines to allow for the engines to turn and for the props not to effect each other, if you can get a manual it will be in there or if you can find a good honda dealer they will be able to help you out. You won't need counter props on those engines in fact you can't buy counter gearboxes for those engines! Tie bars yes they are crazy money I'm after one for my 90's. And now unfortunately I'm doing this on my phone and can't see your other questions so that is all from me!
__________________

__________________
Black Dog Marine
www.blackdogmarine.com
Turbodiesel is offline   Reply With Quote
Old 11 December 2013, 15:01   #3
Member
 
Country: UK - England
Town: Looe
Make: Delta
Length: 4m +
Engine: Mercury
Join Date: Apr 2004
Posts: 1,335
I'm back after reading the post! The controls will be pretty straight forward just double them up! Fuel tanks you can do either really but I would have two tanks one feeding each engine for safety, and two fuel/water filters.
__________________
Black Dog Marine
www.blackdogmarine.com
Turbodiesel is offline   Reply With Quote
Old 11 December 2013, 15:07   #4
Member
 
Country: UK - Scotland
Town: Argyll
Boat name: Helena
Make: Birchwood
Length: 5m +
Engine: Inboard Diesel 250hp
Join Date: Jun 2011
Posts: 116
I'd agree with rob on this one controls will go together no probs and as you suggested run engines on separate fuel tanks. I'd also look at using twin batteries too and put an emergency link in incase of emergencies and don't forget the earth link. One thing when deciding on width apart is to check distance first then see if you can get a tie bar to suit without major modification.
__________________
peterwhite 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 04:39.


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