Bravo 3 to Bravo 1?

[ELIMINAT THIS]

How much am I looking at for the lower? Is the gear ratio determined by the lower or the upper?
$750 obo I will post pics next week.

[U.T.B.A.V-Drive man]

This was my problem switching from the Bravo 3 to a Bravo ZX. This is on a cat type hull (Warlock deckboat). For the Bravo 3 they cut the hole lower to put the X dimenson down. When I put the ZX on, the center of the prop was 6 inches below the hull, which is 3 inches to much. Now I'm looking for a shorty or put the Bravo 3 back on. If the Bravo 1 lower case is shorter the the Bravo 3 and they match up, why didn't the so call pro's tell me. If I were you I would call the boat builder and ask what the X dimenson is, and tell him what your doing.

[Don7070]

This was my problem switching from the Bravo 3 to a Bravo ZX. This is on a cat type hull (Warlock deckboat). For the Bravo 3 they cut the hole lower to put the X dimenson down. When I put the ZX on, the center of the prop was 6 inches below the hull, which is 3 inches to much. Now I'm looking for a shorty or put the Bravo 3 back on. If the Bravo 1 lower case is shorter the the Bravo 3 and they match up, why didn't the so call pro's tell me. If I were you I would call the boat builder and ask what the X dimenson is, and tell him what your doing.
Thanks a lot. That's what I wanted to make sure of.

[Havasu47]

The Bravo I and Bravo III are EXACTLY the same dimension from the crankshaft centerline to the propshaft centerline. The Bravo III's are sometimes mounted lower because they are designed for driveabliity, not performance. If the x dim is too low for a B I it is too low for the B III.
His question was: "What does it take to change it"?
Check you propshaft location in relation to your hull bottom. Call your boat mfg and ask them if a B I will give you the performance gains you are looking for with the x dimension you have.

[U.T.B.A.V-Drive man]

The Bravo I and Bravo III are EXACTLY the same dimension from the crankshaft centerline to the propshaft centerline. The Bravo III's are sometimes mounted lower because they are designed for driveabliity, not performance. If the x dim is too low for a B I it is too low for the B III.
His question was: "What does it take to change it"?
Check you propshaft location in relation to your hull bottom. Call your boat mfg and ask them if a B I will give you the performance gains you are looking for with the x dimension you have.
47, With the B3 and the 454 Mag the boat jumped on plan without any bow lift it would tach out @ 5000 RPM and run close to 60 MPH. After I put in the HP500 with the ZX drive with a 28 pitch then a 26 pitch prop the boat had a vary hard time getting on plane with out nurseing it and driving back and forth. It would pull the motor down so bad it would sputter and back fire through the carb. I even bought a Hydromotive 5 blade 25 pitch, it was a little better but I could only get 4200 RPM's and 60 MPH. I put on another Bravo 1 22 pitch and it came out of the water OK and got 5100 RPM @ 70 MPH. So if I want to run a bigger pitch prop I have to raise the X dim. Just for fun I'm going to put the B3 back on to see what it does with the HP500. You are right the B3 was made to hall people not to go fast.

[U.T.B.A.V-Drive man]

I put the Bravo-3 back on. It brought the boat on plan with no problem. The good part is I got the motor (HP500) to it''s red line RPM (5400) + 400 more. When I shut it off the boat speedo was @ 70 and climbing.

[duffster]

I have a B3 in my Essex21 with a 502EFI and the holeshot speed is out of control. Zero to warp in seconds.
I put the Bravo-3 back on. It brought the boat on plan with no problem. The good part is I got the motor (HP500) to it''s red line RPM (5400) + 400 more. When I shut it off the boat speedo was @ 70 and climbing.