What makes a Bravo III outdrive better than Bravo I I

Sure would be nice if the people would update their signature so we would not have to guess the type of boat they have.:smt101 How hard would it be:huh:
 
I went from a 240 sundancer with alpha 1 to a 240 sundeck with a bravo 3. I usually dock with the port side to the dock. With the alpha 1 I could approach the dock at an angle and turn the wheel all the way to the right and hit reverse and the stern would spin right around to the dock. With the bravo 3 the stern will not spin around with this same manuver. It requires mostly forward gearing and steering to get parallel to the dock.
 
IMHO - it has more to do with the different hulls than the out drive. The BIII is going to get alot more bite than your Alpha did.

I went from a 240 sundancer with alpha 1 to a 240 sundeck with a bravo 3. I usually dock with the port side to the dock. With the alpha 1 I could approach the dock at an angle and turn the wheel all the way to the right and hit reverse and the stern would spin right around to the dock. With the bravo 3 the stern will not spin around with this same manuver. It requires mostly forward gearing and steering to get parallel to the dock.
 
I went from a 240 sundancer with alpha 1 to a 240 sundeck with a bravo 3. I usually dock with the port side to the dock. With the alpha 1 I could approach the dock at an angle and turn the wheel all the way to the right and hit reverse and the stern would spin right around to the dock. With the bravo 3 the stern will not spin around with this same manuver. It requires mostly forward gearing and steering to get parallel to the dock.


I make a similar maneuver with my 270 AJ and BIII. I have no problems with the rear end tucking in against the dock when I turn the wheel and engage reverse. Works when approaching from either direction. Maybe it's just practice, but I can approach the dock, turn, engage reverse, and snuggle up to the dock without any back and forth or multiple steering inputs.

It's a huge improvement from my previous 22' Larson with Alpha. With that one it was definitely harder to dock, and due to the rotation of the prop, more difficult to dock when approaching from one direction than the other (can't remember which way).

As chuck said, hull design likely has significant influence on slow speed handling and docking.
 
If I understand it correctly, A B-II drive is a single prop drive for twin applications. It's designed for to handle high-torque applications to move big boats, like a big cruiser or houseboat. It can swing up to a 20" prop (big!).

B-II drives are an upgrade from the original Alpha series. As mentioned, they have dual props on a single drive, and are intended for single or dual engine applications. They have better handling than a single prop drive, but can't handle the same torque as a B-II drive. Max prop size is 16".

I've never actually seen a regular pleasure boat use a B-II drive. The vast majority are Alpha drives, or B-III drives. A 260 Sundancer isn't going to have a B-II drive - it's not the right application.
 
If I understand it correctly, A B-II drive is a single prop drive for twin applications. It's designed for to handle high-torque applications to move big boats, like a big cruiser or houseboat. It can swing up to a 20" prop (big!).

B-II drives are an upgrade from the original Alpha series. As mentioned, they have dual props on a single drive, and are intended for single or dual engine applications. They have better handling than a single prop drive, but can't handle the same torque as a B-II drive. Max prop size is 16".

I've never actually seen a regular pleasure boat use a B-II drive. The vast majority are Alpha drives, or B-III drives. A 260 Sundancer isn't going to have a B-II drive - it's not the right application.

My 95 Campion had a Bravo 2. Quite a few cruisers of that day had the Bravo 2. The B3 was new and more expensive and more complex than the Bravo One and the B2 so the B1 and B2 were used until the B3 became more proven IMO. The B2 is much stronger than the Alpha. Other than gearing, the drive is virtually the same as a B1 and B3 right down to the lower unit. The B2 swings a larger prop, but is geared lower so the prop spins slower. Those two things made the stern walk effect much more pronounced in single engine B2's like my Campion. It backed in a circle if the helm was straight. The prop torque list while underway was more pronounced too. My deep V Campion cruiser needed almost full tab on the port side only to hold the boat flat while underway. The props are a lot more expensive than an Alpha, but similar to B3. Less market and more metal. I bought a Merc stainless B2 prop and it was CAD$1200 at a time when a stainless merc Apha props were more like $400.

That said, in a dual engine cruiser, I would not hesitate to buy a Bravo 2 set up.
 
yes a marvel of engineering and beautiful when shiny and new. It's a real strict service program that's required to keep them that way. Iv'e owned one and experienced great performance on My 270 Dancer. Iv'e also repaired dozens of them.The issue is a strict service interval as it pertains to corrosion. The advantage that the twin prop set brings to performance is also part of its increased corrosion potential. The huge low pressure developed by the twin prop and the fact that itself is a gigantic cathode , leaves it very vulnerable to corrosive loss if any of the system safeguards are ignored. The bulk of the corrosive loss takes place right where you would imagine ;on the lower case and then migrates to the trim cylinders. Mercruiser realized the problems years ago and changed the design to include additional anodes on the anti cav plate and even the prop nut to counteract the corrosive potential. I have worked on a lot of these over the years and the only reason you may experience this terrible loss is if you neglect the anti corrosion system . As soon as you are in the sea , loss can begin . In fresh warm water here, I would perform twice yearly anode changes on customers with magnesium anodes, check the Mercathode system and continuity system and dress the enamel when needed. As for the machinery in general , its very efficient in moving boats along especially on medium size single cruisers . I do recall backing down in a straight line as well,but repairs are quite expensive both in internal parts due to their complexity ,as well as corrosion remediation if left unchecked .If possible don't keep them in the water when not in use.
 
oops old post
 
B-II is way stronger and used in higher HP vessels as well as larger heavier vessels. My 270 DA has one and it is bullet proof and I would never trade it.

MM
 
B-II is way stronger and used in higher HP vessels as well as larger heavier vessels. My 270 DA has one and it is bullet proof and I would never trade it.

MM
When looking to upgrade from the pre alpha in our 245, the B2 seemed to come up the most in this neck of the woods. Actually see quite a few have switched from the B3 to 2 as well after having the corrosion issues. The big foot print has added much better low speed maneuverability and hole shot. Lower min plane speeds as well. If pulling hard out of the hole it will pull to port pretty good. Never really thought about it but I guess it is more of the stern walking starboard. Easy to compensate for when you know it is coming though and not an issue if powering up slowly. Pretty happy with it.
 

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