​Bravo 2 to temporarily replace Bravo 3

DeepBlue2010

Lieutenant
Joined
Aug 19, 2010
Messages
1,304
Gentlemen,
I lost my Bravo 3 last summer to a submerged log. My plan is to rebuild my 454 and get a new Bravo 3X. However, I have a Bravo 2 with the same ratio (2.00) in my garage that I bought for my other boat to replace the Alpha. Can I run my 2855 on that Bravo 2 for a summer or two?
Usually, it is just the 3 of us (wife and son) on the boat with an occasional friend or two but mostly just us. If it is OK, what should I expect ? or prep for ? in terms of potential loss of performance and handling?
One more question, my B3 was propelled by dual 24P 3 blades each, what prop should I go for to power the B2?
 

mr300z87

Senior Chief Petty Officer
Joined
Sep 15, 2010
Messages
694
Hi first let me say I am no expert, but I do have experience with the B2 drive. My 21 ft invader (see signature file) was originally equipped with a B2 drive and I have documentation to prove it. Now I do know that B2 drives are not designed for 21 ft boats and it even had 3 in of the skeg cut off to make it work. Did it work yes the boat jumped up on plane and did 40 mph. I think I was running a 23 pitch prop but it came to me with a 25 pitch cupped prop. The boat is an 89 and it was used by the previous owner this way since new. The only down side I can see with this as a temporary solution is B2 props are expensive. So I think to answer your question yes it will work. I can tell you that I switched to a B1 and never looked back, even sold the B2. Mike
 

wrvond

Chief Petty Officer
Joined
Mar 2, 2010
Messages
597
Yes, you can directly bolt up the B2 in place of the B3. About the only difference you are really going to see is a bit of walking while trying to maneuver at low speed.
Don't know what is called for on your boat, but my "similar" Sea Ray uses a 17.5" 23P stainless prop on a B2, and it works just fine.
 

DeepBlue2010

Lieutenant
Joined
Aug 19, 2010
Messages
1,304
Thanks for the feedback guys. Just to clarify, I am aware that the upper unit of the two drives are identical so B2 will bolt in with no problem. I am specifically concerned with any potential power loss and the size of the prop for it. Has anyone done this before or any of our experts can give me some pointers?
 

wrvond

Chief Petty Officer
Joined
Mar 2, 2010
Messages
597
Between friction losses, torque required to spin two props vs. one, and cavitational losses, the efficiency of one system over another is pretty much a wash.
B3 owners/salesmen are quick to point out the better handling characteristics while docking of the one, and B2 owners/salesmen tout the greater dependability and cooler running of the other, but neither claims to get up on plane quicker or provide better top end speed. Overall performance is so close it is generally considered pointless to convert from one drive to the other without some external impetus such as yours.
It's more a case of the grass is always greener than anything else.
 

thumpar

Admiral
Joined
Jun 21, 2007
Messages
6,138
The Bravo 2 is generally meant for large heavy boats. The is why it has a large diameter prop. You are probably going to lose holeshot and some handling but otherwise I think you will be OK. Just keep in mind the Bravo 2 is longer when in shallow water.
 

HT32BSX115

Supreme Mariner
Joined
Dec 8, 2005
Messages
10,083
Can I run my 2855 on that Bravo 2 for a summer or two?
You absolutely can. It'll work ok but will not have the holeshot of the Bravo III......It would be better than a Bravo I because of the larger diameter prop. (holeshot is all about square inches of prop in the water pushing water) AND if you put a 4 blade on it.....it will help the holeshot.

The Bravo 2 is generally meant for large heavy boats.
Isn't a a Bayliner 2855 a "large heavy" boat by most standards?
To be sure the Bravo II is used on many different large heavy boats, but A 2855 should approximate that.


B3 owners/salesmen are quick to point out the better handling characteristics while docking of the one, and B2 owners/salesmen tout the greater dependability and cooler running of the other, but neither claims to get up on plane quicker or provide better top end speed. Overall performance is so close it is generally considered pointless to convert from one drive to the other without some external impetus such as yours.
It's more a case of the grass is always greener than anything else.
I beg to differ, I had a OMC (460) King Cobra engine and drive in my '87 21ft FourWinns Liberator and it was a complete DOG out of the "hole" but would run about 60mph once it finally got up on a plane.

I removed the OMG-460 and "drop-in" replaced it with a 97 7.4L Bravo III and the "Holeshot" difference was nothing less than spectacular!

I can now beat many ski boats out of the hole and even if they do beat me out of the hole (slightly) I blow by them almost immediately because of the incredible acceleration up to the 57mph top speed......

Yes, you can directly bolt up the B2 in place of the B3. About the only difference you are really going to see is a bit of walking while trying to maneuver at low speed.
Mine did that with the Cobra and still does it with the Bravo III. That's really more a common characteristic of a Deep-Vee hull being pushed from "behind" than the drive that pushes it
 

thumpar

Admiral
Joined
Jun 21, 2007
Messages
6,138
Try the prop you have and see how it does. It may be perfect or you may want to adjust but at least you have a starting point.
 

HT32BSX115

Supreme Mariner
Joined
Dec 8, 2005
Messages
10,083
Try the prop you have and see how it does. It may be perfect or you may want to adjust but at least you have a starting point.

Yes. Definitely try the prop that came on the drive and carefully note (drive-trimmed) top speed and RPM on a day lightly loaded with a slight "chop"....

If your engine turns rated RPM at full throttle, and gives a similar top speed (compared to your previous top speed) you're right where you want to be.

What top speed did you get before? is your 454 full throttle (WOT) RPM 4600?
 

DeepBlue2010

Lieutenant
Joined
Aug 19, 2010
Messages
1,304
Gentlemen,

I bought the Bravo 2 without prop so I don't have any prop for it. My 454 is carb and it is rated at 4600 WOT
 

alldodge

Moderator
Staff member
Joined
Mar 8, 2009
Messages
40,581
I think your biggest issue is finding a 24 pitch B2 prop, I'm finding they go up to 23 pitch with used. Ebay has several for sale in the $400 range (new $500 range). Have found new 3-blade at 25 but no 24's , also found 4 and 5-blade props.
 
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