Reply
 
Thread Tools Search this Thread
 
Old 09 July 2014, 07:45   #21
Member
 
Country: USA
Town: Portland, OR
Make: Zodiac F470
Length: 4m +
Engine: Suzuki DF25EL
Join Date: Jun 2013
Posts: 231
Particularly higher RPM at lower height does not add up. Even if performance suffers at excessively high motor position because of ventilation. Engine is free to spin even faster.
__________________
SIBRider is offline   Reply With Quote
Old 09 July 2014, 18:56   #22
Member
 
Locozodiac's Avatar
 
Country: Other
Town: Lima-Peru
Boat name: Nautile
Make: Sea Rider 450 Rib
Length: 4m +
Engine: Tohatsu 5/18/30 HP
Join Date: Sep 2007
Posts: 1,998
Stubborn Sibrider,

Knowing having a different type of inflatable than the post was meant for, why don't you post your own findings instead of taking for granted my water tests and keep contaminating my near whole post with your issues.

If you are happy with your combo performance which seems not, Alleluia. May the Northern Waters be with you...

Happy Boating
__________________
Locozodiac is offline   Reply With Quote
Old 11 July 2014, 20:28   #23
Member
 
Projectile's Avatar
 
Country: Canada
Boat name: WB465
Make: Zodiac
Length: 4m +
Engine: 2013 ETEC 30
Join Date: Dec 2012
Posts: 256
Locozodiac:

In your experience, after sea trials with SIBS, what is the usual range of heights of the AV plate relative to the bottom of the transom that usually produces good performance and the type of lower end water flow that you appreciate?

I'm thinking that my ETEC 30 will have to sit with AV plate about 2 inches below bottom of transom on my WB465 to get rid of ventilation. Is that something that you commonly find, or would that be unusually low, in your experience?
__________________
Projectile is offline   Reply With Quote
Old 14 July 2014, 18:28   #24
Member
 
Locozodiac's Avatar
 
Country: Other
Town: Lima-Peru
Boat name: Nautile
Make: Sea Rider 450 Rib
Length: 4m +
Engine: Tohatsu 5/18/30 HP
Join Date: Sep 2007
Posts: 1,998
Proyectile,

Let's see if we can work this out together, I'm more than willing to do so. Will need to forget all about AV plate sitting on a dry installation as all engine owner's manuals blindly recommends. Dry engine setups most times doen't work properly once boats are tested on water at speed/plane.

Regarding inflatables for a perfect setup you have to deal with tubes diameters, transom heights and engine brands, all of which doesn't match between fabricators. Imagine all engine brands fabricating a dedicated engine that matches all inflatables sib/rib brands models.

Go to the other side of the pond and read this new post, has new info added, let me know if you fully understood at least the plain AV plate brand theory starting second post.

Opt Engine/Transom Height - iboats Boating Forums

Happy Boating
__________________
Locozodiac is offline   Reply With Quote
Old 14 July 2014, 21:35   #25
Member
 
sparky666's Avatar
 
Country: UK - England
Town: Looe/Fowey
Make: Honwave 4.0
Length: 4m +
Engine: mariner 20 4 stroke
Join Date: Oct 2013
Posts: 46
Honwave 4.0 with 20 hp merc 4 stroke on the transom splashed like a shower , raised the motor 18 mm , no more splashing and now hitting 6000rpm a gain of 200rpm
Downside some cavitation on cornering and in choppy seas also my hole trim settings only give higher or lower than 90, I opted for higher as I don't like to plough
Great topic that through my own Experience totally accurate
Keep up the good work
__________________
sparky666 is offline   Reply With Quote
Old 14 July 2014, 22:00   #26
Member
 
Locozodiac's Avatar
 
Country: Other
Town: Lima-Peru
Boat name: Nautile
Make: Sea Rider 450 Rib
Length: 4m +
Engine: Tohatsu 5/18/30 HP
Join Date: Sep 2007
Posts: 1,998
Sparky,

Good to read it worked near perfect for your setup. Just for the reccord, the splash was over or back transom ? If with aereation on close turns try different shim heights like 10 mm.

Check visually water flow height, must skim right under water deflector plate, with different minimum shim heights try to match that ideal settting.

Merc's are rebadged Tohatsus, that's why with splash issues too..

Happy Boating
__________________
Locozodiac is offline   Reply With Quote
Old 15 July 2014, 02:44   #27
Member
 
sparky666's Avatar
 
Country: UK - England
Town: Looe/Fowey
Make: Honwave 4.0
Length: 4m +
Engine: mariner 20 4 stroke
Join Date: Oct 2013
Posts: 46
I'm a big fan of running a high engine, my old eurosport with a 90 2 stroke had the cav plate on top of the water and it was perfect
Bit it was a lot more stable and had a clean hull so cavitation was never a problem and it always got plenty of cooling water
The sib has a more unreliable underside that tends to mess the water up (all that air and turbulence )
Good compromise boat though
__________________
sparky666 is offline   Reply With Quote
Old 17 July 2014, 20:21   #28
Member
 
Locozodiac's Avatar
 
Country: Other
Town: Lima-Peru
Boat name: Nautile
Make: Sea Rider 450 Rib
Length: 4m +
Engine: Tohatsu 5/18/30 HP
Join Date: Sep 2007
Posts: 1,998
You won't know the real performance difference if you have not tried it out, try a 10 mm shim and test same, unless you already have bolted that engine to transom. The ideea is to take the max HP out from portable engines and ligh sibs.

Happy Boating
__________________
Locozodiac is offline   Reply With Quote
Old 18 July 2014, 04:53   #29
Member
 
Projectile's Avatar
 
Country: Canada
Boat name: WB465
Make: Zodiac
Length: 4m +
Engine: 2013 ETEC 30
Join Date: Dec 2012
Posts: 256
Hi Loco,

I understand what you're saying.

I asked you a clear and straight forward question in my last post in this thread. Do you know the answer?
__________________
Projectile is offline   Reply With Quote
Old 08 June 2019, 08:43   #30
Member
 
Country: UK - England
Town: Cambridgeshire
Boat name: Nimrod II
Make: Aerotec 380
Length: 3m +
Engine: Yam 15 Tohatsu 9.8
Join Date: Nov 2007
Posts: 8,264
>>>If you could instantly modify the transom height, which of the 3 lower leg heights (pic 2) would you choose for top boating, what kind of water performance would you expect to achieve with the chosen one ?


Re the question above here is your thread Locozodiac with lots of information.
__________________
Fenlander 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




All times are GMT. The time now is 10:13.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2024, vBulletin Solutions, Inc.