Props

***coxgreen*** · 05-08-2008, 01:44 PM

For those considering...

I have a '97 Shabah Z210, 250hp Alpha 1, that struggled a bit to plane out. I put a Mercury High Five stainless prop on it, with the same pitch as my 3-blade, and my boat jumps right out of the water and haven't noticed any loss of speed at WOT.

Prior to changing the prop I considered Hydro-foil. I'm glad I went the prop route instead.

The best $300 I have spent (was patient and waited for one to show up on Craig's List).

***indykoch*** · 05-08-2008, 03:30 PM

That's great! Although I've never heard of a 5 blade keeping the same top end as the 3 blade of the same pitch. I'm glad it worked out for you! Are the diameters of the 2 props the same?

My first suggestion would have been Smart Tabs. I'm a firm believer in those things! Better hole shot, better ride (seems to "cut" through the waves MUCH better), less low speed wonder, etc.

But if this worked as well... great! Thanks for sharing.

bpfirrman · 05-08-2008, 05:07 PM

I currently have a SS 14.5 x 19p on my 180 shabah with 190hp 4.3. I have a hydofoil as well, what prop should I get to add top end and still maintane hole shot? My boat planes super fast in just a few seconds but I want a little more top end. I was thinking of a 4 blade 20 pitch to maintane hole shot but add few MPH to the top, would that work?

***mikeyt*** · 05-08-2008, 06:08 PM

Increasing your pitch to 21 will increase your top speed and lower your top end rpm by about 200-300. For example, if you are hitting 47-48 mph at 5000rpm right now a change to a 21 pitch prop should increase your top end to 50-51 mph & drop your rpms to around 4700 - 4800 at top speed. A 4 blade, 20p SS prop will likely give you a top speed of 49 - 50mph and have your rpms at 4800 which will give you a little more top end without sacrificing any of the grunt and it should give you a little more mid range pull. The thing is to keep your rpm's within the recommended range for your motor. The 4.3 has a range of 4400 to 4800 rpms.

Understand though this doesnt apply 'right to the tee'. Each boat (even though they may be the same size / motor) can be just a little different but the above will be a close guideline. I have the same combo as you and have installed a 4 blade - 20p SS prop & this is what i am expecting.

As for the hydrofoil, i'm with Indykoch. Smart tabs are better.

bpfirrman · 05-08-2008, 06:58 PM

I will see what kind of MPH I get this weekend. Last week with 4 people and full tank I was only getting about 40mph and 4300 RPM, but when I took the boat out of the water I noticed that the prop was damaged(damn driftwood). It was also the first time the speedo was working(clogged hole). I pick up the repaired prop tomorrow and it will be just me and wife this weekend and only 1/2 tank. If I am not happy with the performance this go round I will put the prop on craigs list and upgrade.

***mikeyt*** · 05-08-2008, 07:11 PM

40 mph & 4300 rpm is quite low for the combo you have. Mine had a 3 blade aluminum 21p prop and would consistently hit 50-51mph at 4850 rpm. What i lacked was some low end & mid range grunt which the 4 blade - 20p SS prop should provide in spades.

You would be best to measure your speed with a GPS though. Boat speedos are notorious for being just 'a lttle off' although if your prop is damaged to a moderate degree it will affect your performance.

***180diablo*** · 05-08-2008, 07:44 PM

I don't have smart tabs installed on my boat, but I have been around here long enough and on another boating webpages to know that Smart Tabs are the way to go.

Bpfirrman, dump the hydrofoil, install I think the 60lb vs 80lb actuators for the smart tabs and enjoy them.

I personally think those hydrofoils look dorky on a sterndrive.

btw - my boat goes 33-35 speedo mph... 14p / 3 blade prop.

***mikeyt*** · 05-08-2008, 09:01 PM

Quote:

Originally Posted by 180diablo

I don't have smart tabs installed on my boat, but I have been around here long enough and on another boating webpages to know that Smart Tabs are the way to go.

Bpfirrman, dump the hydrofoil, install I think the 60lb vs 80lb actuators for the smart tabs and enjoy them.

I personally think those hydrofoils look dorky on a sterndrive.

btw - my boat goes 33-35 speedo mph... 14p / 3 blade prop.

a 14 pitch prop ?? are you sure ?? I would have thought you would run a 17p or 19p. No wonder ya only do 33-35mph with that 3.0

***dwmax*** · 05-08-2008, 10:57 PM

180 diablo my old boat was a 18ft cobia bow rider 1988 3.0 OMC IO and I had a 17 pitch 3 blade ss prop on it and that thing would do 45mph and still jump right out of the water on take off you should honestly think of upgrading to a 17p propI think you would like it better