Reply
 
Thread Tools Search this Thread
 
Old 05 February 2011, 16:12   #11
RIBnet supporter
 
gotchiguy's Avatar
 
Country: UK - England
Town: Dinard, Brittany
Boat name: Into the Red
Make: Osprey Vipermax
Length: 7m +
Engine: Evinrude E-tec 250HO
MMSI: 235 076 114
Join Date: Apr 2009
Posts: 1,948
RIBase
Quote:
Originally Posted by willk View Post
That's the result of a deep V and a 2.62m beam. Standard rigging on a Redbay, bear in mind that the Etec 90s are very slim

The crowd who commissioned mine, replaced her with this one, Déjà vu all over again, eh?
Are you going for another RIB then or as Polwart has suggested converting to the SIB on a full time basis?
__________________
gotchiguy is offline   Reply With Quote
Old 05 February 2011, 17:03   #12
RIBnet admin team
 
willk's Avatar
 
Country: Ireland
Make: Redbay Boats
Length: 9m +
Engine: 370hp
Join Date: Feb 2008
Posts: 12,925
RIBase
Quote:
Originally Posted by gotchiguy View Post
...Polwart has suggested converting to the SIB on a full time basis?
__________________

__________________
willk is offline   Reply With Quote
Old 05 February 2011, 17:22   #13
RIBnet supporter
 
gotchiguy's Avatar
 
Country: UK - England
Town: Dinard, Brittany
Boat name: Into the Red
Make: Osprey Vipermax
Length: 7m +
Engine: Evinrude E-tec 250HO
MMSI: 235 076 114
Join Date: Apr 2009
Posts: 1,948
RIBase
Quote:
Originally Posted by willk View Post
I'm glad to hear it!!
__________________
gotchiguy is offline   Reply With Quote
Old 06 February 2011, 04:58   #14
Member
 
Country: Other
Town: Stanley, Falkland Is
Boat name: Seawolf
Make: Osprey Vipermax 5.8
Length: 5m +
Engine: Etec 150
Join Date: Mar 2006
Posts: 3,688
Quote:
Originally Posted by willk View Post
That's the result of a deep V and a 2.62m beam. Standard rigging on a Redbay, bear in mind that the Etec 90s are very slim

The crowd who commissioned mine, replaced her with this one, Déjà vu all over again, eh?
If they carry on heading towards that rock at full moo they're going to need another one in about 5 seconds

Anyway mr willk I have a bone to pick with you - why didn't you sell your boat last year
__________________
A Boat is a hole in the water, surrounded by fibreglass, into which you throw money...

Sent from my Computer, using a keyboard and mouse
BogMonster is offline   Reply With Quote
Old 06 February 2011, 06:02   #15
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 gotchiguy View Post
Fair enough, there is no need to discuss the reasons, the single v twin debate has raged at much length in the past.

9D820 is the one to answer that really but from what he has said in the past, at these sort of HP levels, yes, twin 40s will be the equivalent of around 75hp~ish. However the fact that there means there is only one prop does mean that there is a little less grip and blade area in the water however the drag is significantly reduced.

To have the same power as your twin 2/s you'd need at least a 90 4/ whereas a good 2/ like an etec or opti would do it for slightly less. You will no doubt be aware of the weight saving with the 2/ and the fact that modern ones have the same fuel economy/no smoke/greater efficiency than a four stroke. I imagine that your two 40s are quite light and they probably would weigh less combined than a single fourstroke of the same HP (speak to 9D280 for the exact science), wheras the modern two stroke would be less than your two engines combined and you would see much greater efficiency and retain/improve the balance of your boat which you would not if you went the 4/ route.

It can be tricky changing from twins to singles, especially when central elephants trunks and holes need to be sealed properly.
The OP ought to pay little regard to this load of bollox.
__________________
Downhilldai is offline   Reply With Quote
Old 06 February 2011, 06:07   #16
RIBnet admin team
 
willk's Avatar
 
Country: Ireland
Make: Redbay Boats
Length: 9m +
Engine: 370hp
Join Date: Feb 2008
Posts: 12,925
RIBase
Quote:
Originally Posted by Downhilldai View Post
The OP ought to pay little regard to this load of bollox.
I figured that unless he'd been underwater since May last, he probably got the general picture there...
__________________
willk is offline   Reply With Quote
Old 06 February 2011, 06:20   #17
RIBnet supporter
 
Pikey Dave's Avatar
 
Country: UK - England
Town: South Yorks
Boat name: Black Pig
Make: Ribcraft
Length: 5m +
Engine: DF140a
MMSI: 235111389
Join Date: Feb 2008
Posts: 7,590
RIBase
A 6m Chinhook with only 80-90hp on the back of any combination/flavour, sounds a bit weedy to me, especially for carrying divers. Stick a single 150 on the back
__________________
Rule#2: Never argue with an idiot. He'll drag you down to his level & then beat you with experience.
Rule#3: Tha' can't educate pork.
Rule#4: See rule#5
Pikey Dave is offline   Reply With Quote
Old 06 February 2011, 06:36   #18
Member
 
blueboy758's Avatar
 
Country: UK - England
Town: Thornaby
Boat name: Storm
Make: Humber Ocean Pro 6.5
Length: 6m +
Engine: Suzuki DF 150
Join Date: Jan 2008
Posts: 335
i have a 5.3 with extra large tubes high bow and deep 'v' with an evinrude 115!!! goes like stink !!! and very efficient when eased back!
__________________
blueboy758 is offline   Reply With Quote
Old 06 February 2011, 06:41   #19
RIBnet admin team
 
willk's Avatar
 
Country: Ireland
Make: Redbay Boats
Length: 9m +
Engine: 370hp
Join Date: Feb 2008
Posts: 12,925
RIBase
Our old dive club 6.1 had/has the same 115 ficht. She fairly clipped along when lightly loaded, but a full compliment of divers (6-8) and kit meant that she was at WOT most of the time in the mid 20s

For 4 divers, I'd say 115 was enough, but 150 would have a big smile factor
__________________
willk is offline   Reply With Quote
Old 06 February 2011, 09:40   #20
Member
 
blueboy758's Avatar
 
Country: UK - England
Town: Thornaby
Boat name: Storm
Make: Humber Ocean Pro 6.5
Length: 6m +
Engine: Suzuki DF 150
Join Date: Jan 2008
Posts: 335
would that have had the right prop on? i've seen the same engine on a ocean pro 6.3 with 4 divers doing 43 ish kt's! even though i have been in boats all my life i'm just getting to grips with different props abnd how much better they can make things
__________________

__________________
blueboy758 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 03:18.


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