New Bravo III 4 blade propset

[Scurvy Dawg]

We have a 2008 Rinker 246 R2 bowrider with the wakeboard setup. We run a full boat wakeboarding and tubing and modest cruising. Found info on the web for the a new propset similar to the Bravo III XR perfromance blades, New Bravo Three - Extra Blade Means Extra Performance.

HERES THE QUESTION. Since we run mostly watersporting and need just a little more power for the hole shot when pulling under load, should I change the propset for more accelaration? I'm looking for low end performance and cruising, not top speed.

Here's the set up: 350 Mag MPI Bravo III, 15.5 diameter 24 pitch prop set, top end 52+ mph at WOT (5000 prm), cruise at 28-30 mph, watersports at 17-19 mph.

Anybody have experience with this new prop set? Any info will be helpful. I see in engine tests at Mercruiser that Chapparal is running this set up on their SSX 236 with the 350 MAG. I also heard that Cobalt is making this "Next Generation Bravo III" standard on some of their boats. I will call Rinker and Mercruiser for more info.

[rhunter113]

I would be curious as well. We have a searay 270SD with a 496 and Bravo 3. We have a hard time wake boarding behind it. If this would improve the low speed performance it would be great.

I have 38 Special for the top end speed needs...

[bbladesprops]

In 1999, while still employed at Mercury Racing, we began development of a new set of B3 propellers. The reason we did this was Formula began mating 500 EFI engines to B3 drives on their sport cruisers. The second generation B3 props (still a 3/3 set up) was cavitation burning so fast we couldn't get 10 hours on the props before their would be a hole in the front prop blades. The new development produced 2 finalists. One set had a 4 blade front which truth be told was a mis communication accident. However, after much testing it was determined the 4/3 had the better cav. burn resistance and the performance was equally as good as the other new development set. What we found was the 3/3 original set was slightly faster still. However, the new 4/3 burned much less and had a slightly better mid range. We decided to release them under the Mercury Racing logo and it took till 2004-2005 to get it done. This is the time frame slightly after my leaving Mercury Racing. The decision to Hi Polish the props came from the management that took my place. Hi Polish looks pretty but isn't a performance related issue.

If a guy wants low end and mid range specifically, the 4/3 is the better choice. If bow lift and speed are the main concern, working the 3/3 is still the better choice. Unfortunately, I believe the 3/3 is going to go away for good.

Now, as far as the new 4/3 versus the Merc Racing 4/3, there doesn't appear to be much difference other than the finish and a bit of a geometry and cup change. Main line propellers has basically created a new propeller option to continue moving forward with new offerings in the market place. It has a duller finish and is priced to offer the consumer a option. And a Hi Polish price point to match the Racing XR version. The whole thing is kind of goofy in that main line has created a product to directly compete with the Racing product.

We have worked with the XR propellers here at BBLADES. We have yet to work with the main line 4/3.

Again, bottom line, 4/3 for low end, 3/3 for top end. Also, go down 1" of pitch if you go from the 3/3 to the 4/3.

Brett

[Scurvy Dawg]

Thanks. Looks like I'll be testing some props this spring. I'll be interested to see the difference at low end towing speeds in relation to the load. I tend to get some cavitation during sharp turns, wonder if that will go away with 4 blades. I would think performance and stability would increase at cruising speed as well, particularly at the Ozarks in rough waters.

[derekpfeiffer]

yeah i've also experienced some problems with some caviation during sharp turns but mostly at higher speeds tho.