Reply
 
Thread Tools Search this Thread
 
Old 11 August 2005, 15:47   #1
Member
 
Country: UK - England
Town: London
Make: Solent
Length: 6m +
Engine: Mercury 150 Optimax
Join Date: Feb 2005
Posts: 13
New Props for 150 Optimax

I am looking for new props for my 150hp Optimax.

Currently running a 19" Laser II, looking for:

a) Something to get more speed

b) Something for more grip in tight turns and pulling up skiers etc

Aware that this will be two different props.

Advice and sellers wellcome.

Many thanks,

James
__________________
jimc is offline   Reply With Quote
Old 11 August 2005, 15:48   #2
Member
 
Country: UK - England
Town: Midlands
Make: Nautique
Length: 6m +
Engine: PCM 5.7l
Join Date: Oct 2003
Posts: 1,082
What rev's are you pulling at WOT with the 19" prop?
__________________
simmons0 is offline   Reply With Quote
Old 11 August 2005, 15:58   #3
Member
 
Nick Hearne's Avatar
 
Country: UK - England
Town: Bucks
Boat name: Blue & Ding Dong
Make: Ribeye,SR4 & Bombard
Length: 6m +
Engine: 115,50 & 15Hp Yams
Join Date: Feb 2004
Posts: 3,252
What speed are you getting at the moment?
Give Julie a call at steel developments, very help full!
http://www.steeldevelopments.co.uk/
__________________
Nick Hearne is offline   Reply With Quote
Old 11 August 2005, 16:03   #4
Member
 
Country: UK - England
Town: London
Make: Solent
Length: 6m +
Engine: Mercury 150 Optimax
Join Date: Feb 2005
Posts: 13
Getting about 5500 revs fully trimmed and can make 46 knots with 4 in the boat, looking to go above the elusive 50 barrier!!
__________________
jimc is offline   Reply With Quote
Old 11 August 2005, 16:07   #5
Member
 
Nick Hearne's Avatar
 
Country: UK - England
Town: Bucks
Boat name: Blue & Ding Dong
Make: Ribeye,SR4 & Bombard
Length: 6m +
Engine: 115,50 & 15Hp Yams
Join Date: Feb 2004
Posts: 3,252
Quote:
Originally Posted by jimc
Getting about 5500 revs fully trimmed and can make 46 knots with 4 in the boat, looking to go above the elusive 50 barrier!!
Clean & wax the hull , kick 3 people out!
Job done & saved £600 on new props
__________________
Nick Hearne is offline   Reply With Quote
Old 12 August 2005, 08:32   #6
Member
 
Country: UK - England
Town: Margate / Ramsgate
Boat name: Bumbl
Make: Scorpion
Length: 8m +
Engine: Yanmar diesel
Join Date: Feb 2002
Posts: 2,837
My Opti 150 max'es out at 5750, so you are not far off. The solent hull has a reputation for being quick but i'm not sure 50knts is attainable with a 150. Are you trimming right out to get these rev's?

I don't know a huge amount about different props but my simplastic view would say try a 17" laser II, try and borrow one if possiable. I don't have one i'm afraid.

I can make 46knts with a 21" laser II @ 5200 RPM and the same speed @ 5500 RPM with a 19", never tried a 17" so please report back if you try it.
__________________
Daniel is offline   Reply With Quote
Old 12 August 2005, 10:51   #7
Member
 
Country: UK - England
Town: Mighty Penryn
Boat name: Little Joe.
Make: Avon Searider
Length: 4m +
Engine: Honda BF50
Join Date: Aug 2005
Posts: 8,872
Props

If your pulling 5500 rpm and the opti maxes at 5750 then more speed cant be obtained. To gain the extra 250 rpm you'd need to fit either a smaller prop or one of a lesser pitch. This will give better pull out but less speed. Another trick is to lightly sand the hull with some fine wet and dry paper. 800 grit with soapy water is good. The top dinghy racers do this, it causes the hull it ride on a layer of minute bubbles which "releases" the hull and reduce drag. Waxing the hull tends to do the opposite and create suction between the hull and the water. It sounds as if 46 knts might be yer lot though.
__________________
Mollers is offline   Reply With Quote
Old 12 August 2005, 11:06   #8
Member
 
Nick Hearne's Avatar
 
Country: UK - England
Town: Bucks
Boat name: Blue & Ding Dong
Make: Ribeye,SR4 & Bombard
Length: 6m +
Engine: 115,50 & 15Hp Yams
Join Date: Feb 2004
Posts: 3,252
Quote:
Originally Posted by Mollulnan
If your pulling 5500 rpm and the opti maxes at 5750 then more speed cant be obtained. To gain the extra 250 rpm you'd need to fit either a smaller prop or one of a lesser pitch. This will give better pull out but less speed. Another trick is to lightly sand the hull with some fine wet and dry paper. 800 grit with soapy water is good. The top dinghy racers do this, it causes the hull it ride on a layer of minute bubbles which "releases" the hull and reduce drag. Waxing the hull tends to do the opposite and create suction between the hull and the water. It sounds as if 46 knts might be yer lot though.
So a sandy bottom goes faster hey
__________________
Nick Hearne is offline   Reply With Quote
Old 12 August 2005, 13:54   #9
Member
 
Country: UK - England
Town: Mighty Penryn
Boat name: Little Joe.
Make: Avon Searider
Length: 4m +
Engine: Honda BF50
Join Date: Aug 2005
Posts: 8,872
Sandy bottom

....may give you a rash also!
Quote:
Originally Posted by Nick Hearne
So a sandy bottom goes faster hey
__________________
Mollers is offline   Reply With Quote
Old 12 August 2005, 13:56   #10
Member
 
Country: UK - England
Town: Margate / Ramsgate
Boat name: Bumbl
Make: Scorpion
Length: 8m +
Engine: Yanmar diesel
Join Date: Feb 2002
Posts: 2,837
My osprey is anti-fouled, often wondered how much this knocks the top speed.
__________________
Daniel is offline   Reply With Quote
Old 12 August 2005, 14:29   #11
Member
 
Country: UK - England
Town: Mighty Penryn
Boat name: Little Joe.
Make: Avon Searider
Length: 4m +
Engine: Honda BF50
Join Date: Aug 2005
Posts: 8,872
Quote:
Originally Posted by Daniel
My osprey is anti-fouled, often wondered how much this knocks the top speed.
Next to nothing with a well applied "High speed" anti-fouling. A chunky missus onboard would be worse!!
__________________
Mollers is offline   Reply With Quote
Old 12 August 2005, 17:04   #12
Member
 
Country: UK - England
Town: Isle of Wight
Length: no boat
Join Date: Oct 2004
Posts: 154
Yes, wet & dry can help, however, use 1000 or 1200 grade. Also, you must rub fore and aft, not across the hull (this would have the opposite effect!). Personally, I not do it as you will never get that lovely glossy finish again.
__________________
rbw156 is offline   Reply With Quote
Old 12 August 2005, 19:19   #13
Member
 
Country: UK - England
Town: Mighty Penryn
Boat name: Little Joe.
Make: Avon Searider
Length: 4m +
Engine: Honda BF50
Join Date: Aug 2005
Posts: 8,872
Quote:
Originally Posted by rbw156
Yes, wet & dry can help, however, use 1000 or 1200 grade. Also, you must rub fore and aft, not across the hull (this would have the opposite effect!). Personally, I not do it as you will never get that lovely glossy finish again.
If a rib is used for what it is intended (they aint yachts), then the "lovely glossy finish" doesn't last too long anyway. Staining from being left in the water un-antifouled is the biggest culprit.
__________________
Mollers is offline   Reply With Quote
Old 12 September 2005, 20:41   #14
Member
 
Country: UK - England
Town: Lymington
Boat name: Farfetched
Make: Solent Ribs
Length: 6m +
Engine: 150hp Suzuki
MMSI: 235021048
Join Date: Apr 2004
Posts: 961
We made 48.9 knots with Kev from Solent at the helm and just me hanging on for dear life at her acceptance trials. Never got above 46.5 with me at the helm.
__________________
brucehawsker is offline   Reply With Quote
Old 12 September 2005, 20:53   #15
Member
 
Country: UK - England
Town: Mighty Penryn
Boat name: Little Joe.
Make: Avon Searider
Length: 4m +
Engine: Honda BF50
Join Date: Aug 2005
Posts: 8,872
I'm running a 19P Vengeance on my 150 Opti. It'll pull about 5300rpm which gives around 42knts on the gps. The pull out is instant and great for the kids wakeboarding. I'm in the process of buying a 21P for use when cruising. I cruise at about 3800rpm which gives approx 31knts with the 19P. Hopefully nearer 35knts for the same revs with the 21P.
__________________
Mollers 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 09:59.


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