Someone learn me about Mercruiser drives please....
 

OK, so I'm a long time gear-head whose been road racing motorcycles for the last 12 years or so. I've had a life-long aspiration to have a "cigarette" boat (note little "c", though I would never rule out a Cigarette either!). So....I'm thinking sometime in the next two years or so, I'm getting one.

As far are Merc drives go...

a) why does everybody seem to hate on the TRS drives? These were drives I remember from back in the day of Scarab 38 KVs and Donzi Crossbow 33's...were there reliability issues or was it because the external transmission was a power hog? Or are they just old?

b) Speedmasters - how about the 3's, 4's, and 5's? They all mount on the same gimbal...yes? Reliability? Parts availability? Prop availability?

c) Bravos....are any of them worth having? What is the part of the drive that tends to fail under high power motors (bevel gears, gimbal bearings, cone gears, etc)? Is it power or torque that kills them? What is the power/torque threshold where they are no longer reliable?

I'd suggest that you spend some time with the search function. There is alot of post about bravo mishaps. Of course SSM drives have issues as well, but not to the extent B1 drives have. I does not matter much which B1 you have. If you put more than rated power i.e 600 hp, though them they will go boom at some point. Even drives that run the rated power between 500-600 hp have a limited life. I am here talking about the XR and upgrades. As you can imagine, B1, B1X are no better. There is no comparison between Arneson/SSM drives and Bravo's. It's a completely different league.

The most common failure is the upper gears. But lower gears, tower, top cap failure, both vertical and prop shafts break too. Also the billet ones. Can you get an Arneson, Indy or SSM V/VI boat, do so.

Just my 2c's

When it comes to the TRS I believe their heavier duty than a Bravo. TRS was the drive to have before they made the Bravo if you planned on building up your motor. They do take more poweer to turn them and with the transmission you loose about a foot of space in the boat. They stopped making them in '93 some parts are not as readily availiable as a bravo. You can usually still find them though if you know where to look. Lot of complete drives for sale out there. I have 3 myself.

Found a site that has some specs of the Bravo lineup ( http://www.perfprotech.com/store )... basically Bravo 1, 1x can take no more than 400 HP and Bravo 2 and 2x can take no more than 450 HP. From y'all's experience, does this sound accurate or just internet "opinion"?

How the TRS / TR's and Speedmaster II's...I'm finding some more internet "knowledge" that leads me to believe that maybe the SpeedmasterII are nothing more than TRS uppers with a "speedmaster" lower on them?...

Thats about it...

This section has hundreds of threads with all the info you could ever want to know. Just start going backwards in the pages and you will find everything you want to know.

As Griff said, do alot of reading on this site. What you'll find is that the Bravo specs quoted above are considered the max for ultimate reliability, but that many are running far above that, and even Merc put out (and warranted) some combos running well above those figures. Reliability becomes lower and attention to driving style becomes more critical as HP goes above 450-500.