Bravo 3 vs. DuoProp - Showdown

[haulnazz15]

I'm interested in a more modern boat with counter-rotational props. I'm familiar with Merc, but I don't find anything particularly wrong with Volvo. Anyone have a recommendation between the two? I know the earlier B3's had corrosion issues, but this will be a late-model and will have a working galvanic corrosion system on it in addition to the fact that I don't boat in salt-water. Engine will most likely be an 8.1L package.

Pluses and minuses to each (drive maintenance, shifting smoothness, common problems) would be appreciated.

 

[JoLin]

Re: Bravo 3 vs. DuoProp - Showdown

At the risk of contributing to a 'Chevy-Ford-Dodge' debate, I loved the SX-series duoprop on my '99 Chris*Craft. Shifted smooth as silk, quiet, simple design, reputation for being extremely robust. Downside is that replacement props are very expensive.

Either is a great addition to a single engined boat as they eliminate prop steer and make it easier to handle in low-speed/docking maneuvers. Dumping it into reverse at idle speed is like applying the brakes on your car.

My .02

 

[haulnazz15]

Re: Bravo 3 vs. DuoProp - Showdown

Well, I know a lot of people like the shifting-smoothness on the SX's, but I believe the B3 and DP both have the cone clutch like the SX, so I'm not sure that the B3 would be any different. If it was alpha vs XS, it's no question the Volvo is probably a bit better technology-wise.

 

[QC]

Re: Bravo 3 vs. DuoProp - Showdown

You might want to check propset pricing. Going to move this to non-repair I/O

 

[haulnazz15]

Re: Bravo 3 vs. DuoProp - Showdown

Yeah, I wasn't aware of that forum. I just didn't want to post it in the Volvo or Merc I/O forum to avoid biased input, lol.

 

[QC]

Re: Bravo 3 vs. DuoProp - Showdown

Yeah it's new, and it is hard for all of us to pick the right place for sure. This belongs here, but putting my non-Mod hat on the traffic is fairly light.

What's your top speed target?

 

[HT32BSX115]

Re: Bravo 3 vs. DuoProp - Showdown

You can argue Volvo--Merc All day long..... Volvo builds really excellent drives.....but I would still choose Mercruiser.....


If you go to Ebay and check how many of each ( drives, parts, "stuff") are available used, the choice will be pretty clear.

I LOOKED and tried to find a VP BBC/DPS used for my boat below when I ripped out the POS King Kobra.

I found a LOT of Merc engines and drives (packages) locally. I NEVER have seen a Volvo engine/drive package for sale locally.

My engine/drive came from a local guy that had a tree fall on his 24' Bayliner while he had it stored in his backyard during Winter

I guess trees never fall on Volvo powered boats!

Yeah, I wasn't aware of that forum. I just didn't want to post it in the Volvo or Merc I/O forum to avoid biased input, lol.

It's still gonna happen though

Regards,


Rick

 

[QC]

Re: Bravo 3 vs. DuoProp - Showdown

I'm thinking you should look for one of these:

Prove to Rick that he simply can't see the boat for the trees . . . :facepalm: Here we go again . . . lol

 

[HT32BSX115]

Re: Bravo 3 vs. DuoProp - Showdown

I'm thinking you should look for one of these:

Prove to Rick that he simply can't see the boat for the trees . . . :facepalm: Here we go again . . . lol

Those are cool!

They have clutch packs for shifting like an auto trans don't they?

 

[Fun Times]

Re: Bravo 3 vs. DuoProp - Showdown

Once you need to do an impeller job, you will wish you had a volvo.

 

[45Auto]

Re: Bravo 3 vs. DuoProp - Showdown

Once you need to do an impeller job, you will wish you had a volvo.

Why is that?

Takes me about 10 minutes to change the impellor on my B3. Pop the serpentine belt (Bravo 3 pump is engine driven, not in the drive), remove the water pump faceplate, swap impellors, stick it back together.

I've never messed with a Volvo, but it's hard to imagine an impellor change being much of a factor in any drive decision even if it's instantaneous on a Volvo.

 

[45Auto]

Re: Bravo 3 vs. DuoProp - Showdown

I'm thinking you should look for one of these:

Aren't they only good for about 350HP?

I could probably get a complete spare boat for the price difference between a Yanmar and an SEI Alpha replacement!

 

[QC]

Re: Bravo 3 vs. DuoProp - Showdown

My point was if Rick thought finding a used DP was hard . . .

 

[HT32BSX115]

Re: Bravo 3 vs. DuoProp - Showdown

My point was if Rick thought finding a used DP was hard . . .

Oh....I never thought they were "hard" to find.....and it appears that they might be about the same price (new)

It's just if you go looking for one, for every "one" you find, you find about 10 Bravo III's.......

Aren't they only good for about 350HP?

I could probably get a complete spare boat for the price difference between a Yanmar and an SEI Alpha replacement!

That may be........ the difference in price might even be related to the YEN-USD exchange rate etc.....

Those are rated for 350hp diesel though....I'll bet they are VERY strong.... The idea of using (wet disc)clutch packs and hydraulic shifting REALLY appeals to me.....

Automatic transmissions have been shifting like that for as longer than sterndrives have been in existence. It's a well designed process. FAR better than cone or dog-clutches.

Plus, they can be designed to "give-a-little" in the event of a prop-strike.

Mercury and Volvo have probably NOT done this because of the added cost of hydraulic shifting.....

I've never messed with a Volvo, but it's hard to imagine an impellor change being much of a factor in any drive decision even if it's instantaneous on a Volvo.

Volvo sea-water pumps are engine driven and have been for many years....

 

[haulnazz15]

Re: Bravo 3 vs. DuoProp - Showdown

Well, it will be on a 30' late-model cruiser as a pair of twins. I have seen several with Volvo DP's and several with Merc B3's. Same engine really, on the same boat models. I just wasn't aware of any advantage/disadvantage between the two drive designs. I'm familiar with the Merc Alpha I's, and have done water-pump/shift shaft maintenance on those, but knew the DP/B3's were engine-driven. I would imagine top speed on these cruisers will be somewhere in the 40mph range, no faster than 50mph for a hull that heavy, so it should be well within the capability of these units. I suppose if I was breaking the 60-65mph barrier it wouldn't likely be with a counter-rotating drive.

 

[HT32BSX115]

Re: Bravo 3 vs. DuoProp - Showdown

I suppose if I was breaking the 60-65mph barrier it wouldn't likely be with a counter-rotating drive.

I do 57mph with my completely stock carbed 454 & Bravo III turning 4600 RPM (rev limited to 4700) .................

I am sure I'll be able go much faster if I put a LOT more HP under te hood....

If you were wanting to break 60-65 mph with a 30 ft cruiser, you would need Mercury Racing 750hp engines and drives !!!

 

[QC]

Re: Bravo 3 vs. DuoProp - Showdown

Yeah, I only asked because Merc recommends B1s above 60. I've never seen DPs on any type of serious performance boat. I have driven DPs at 55 a few times. All good to there.

 

[haulnazz15]

Re: Bravo 3 vs. DuoProp - Showdown

I do 57mph with my completely stock carbed 454 & Bravo III turning 4600 RPM (rev limited to 4700) .................

I am sure I'll be able go much faster if I put a LOT more HP under te hood....

If you were wanting to break 60-65 mph with a 30 ft cruiser, you would need Mercury Racing 750hp engines and drives !!!

I don't think a B3 mated to the 750HP engines would last very long, lol. Although twin 750HP merc's ought to give me one of the fastest cabin cruisers on the lake! I'd imagine the dry-sump six and herring props are more aligned with that engine package.