Smitty

iTrader: (1)

Has anybody broken a 1.36 ratio Bravo drive ?? If so give me the details of your setup : I.E. How much power, V or Cat, how heavy of a boat etc.

I'm just about done putting my motors back in and I have 775 hp and 840 ft lbs torque. I know the 1.50 ratio drives don't last long with this power level but I haven't heard of too many 1.36 ratio drives dying, probably because they are far and few but I am just curious.

SCRAPMAN1

Start Saving Up For A Stack Of Spares. The Power You Speak Of Is Way Past The Bravos Capabilities. To Answer Your Question The 1.36's Break Just As Easy. The Weight Of The Boat And The X Dimension As Well As Driving Style Has Alot To Do With It. I Have A Friend With A 30' Cat With 600 Hp Per Side And 1.36 Bravos That Has Gone Through 3 Drives In A Year And A Half Driving Conservatively. I Have A 50' V With 1.36 Bravos On 575s That Has Eaten 4 Drives In Two Years Driving Conservatively. One Heavy Boat One Light Both With 600 Per Drive Both Break Them. Hope This Helps.

jdnca1

Convert to the "X" style gears and either Teague prop shafts or the "BIG" Mercury prop shafts. The "X" gears are far surperior to the old style...I know several running this set-up on single and twin engine cats behind 800+ hp blower motors with very few issues....no sissying around either, they run them hard.... I know of one set that went 230 hrs.

As scarab stated, the driving style, X dimension, and weight are big variables....none of them will take flying in and out of the water at will......

I'd have to say that most boats with big blower motors I know of run 1.36 drives, mainly due to more prop selection before running out of pitch.....

Steve Snider

The question is how long until the Bravo breaks not if...It doesn't matter what or whose gears are in the gearcase. The Bravo design of three upper gears will not sustain that kind of horsepower very long. Imco went to the concept of adding a idler (fourth gear) and it works. Unfortunately the outdrive will not shift so a transmission is required mounted in the extension box. I used to make a lot of money rebuilding Bravo drives when I had my own shop up north. I ran a 800 hp Eliminator Cat and broke a couple 1.36 drives myself. Once I was trying to back off the trailer at a shallow ramp and snapped the input shaft. All I can say is baby the drive..ease it on plane and bump it up a little at a time-rough water and airing out the drive will make it grenade when the prop reloads. Best of luck though...