srq,
I can't remember the post, did I list the components of that gear?

It was an XR upper gear. Not sure when it was made and if they have made them the same since then.

Here is the list again.

Zn 1.7%
Ni 3.0%
Cu 7.3%
Fe 86.7%
Mn .5%
Cr .14%
Ti .11%

Dick

Thank you Mr. Tyce
Yes those are the numbers you posted a long while back. Glad you confirmed them to be an XR upper.
Today I'm searching locally for a lab that has the same XRF alloy analyzer. Hopefully I get repeatable results. I'll keep you in the loop.
Thanks again
Warren

Wouldn't it be less expensive and less head ache. If you just get a new drive that will handle the power and not continually break again and again and again.

:food-smiley-007:

No need for popcorn. That gesture was funny though and since I don't post much I guess I had that one coming. lol
In short, been building performance drives for 30 plus years. My Master Mercruiser # is FL0178M . To be able to achieve the "Master Tech" status back then one not only had to excel in all areas of technical professionalism but also had to be voted by the tech reps at that time for entry. Currently all I build is performance drives and lower units, had my hands on my first Bravo drive in 1984. I think you'll find my track record very adequate and hope to earn the forums respect over time.
I've been asking some questions lately to expand some engineering I'm doing on the Bravo XR drives. With some collaboration,not condemnation I believe I can come up with a few improvements that would be beneficial for some on the forum that won't break the bank.
Thanks in advance and hope to get a chance to meet a few of you.
Warren

So where have you been doing all this amazing work for the past 30 years?

I started in Orlando as a Mercruiser and Merc Outboard dealer for a good number of years and the moved back to Sarasota about 12 years ago where I build drives at Phantom Boat co. . Never said anything about amazing, I just like making Bravo's reliable and fast.
Warren

Personally I think your beating a dead horse. There are better options than a bravo and a cure doesn't make sense as every one is making money fixing them. So a real cure would be bad for business for all those shops who rely upon the revenue the repairs generated. Mercury knows this as they make tons off the bravo annuities.

Not trying to be a smartass (really). Mercury has such a huge problem with these drives XR/XZ. And they just keep ignoring it. Maybe a guy with your long term relationship with them would have some pull to get things changed. Or at the very least they would be willing to work with you to help them develop a "performance" drive. Because it sure would seem they do not have a person that gives a crap or has the knowledge to fix the problem. I wish you the best as I'm sure ALOT of other Bravo owners also.

Gaz, I'm going to try and stay on task to my original post but will take a minute to agree with you for the most part and I never really took any comments as derogatory so we're good here. I share the frustrations a lot of performance Bravo B1, XZ, XR owners have. I am a Mercruiser loyalist to the core and do believe the engineers for the most part did a pretty good job at listening to the bulk of reasonable complaints. The engineers and inside connections I once had with Mercury have long since retired and the new generation is a little more tight lipped so here I am going to have to do some reverse engineering to get the answers I want.. I will say Kudos to the engineers that took on the task of the original design bugs as these were addressed early on and so for the most part the Bravo drive is a fairly reliable outdrive for purposes intended. Where the loudest noise comes from now are boat owners exceeding the drives intended capabilities and yes playing in the performance field can get expensive. Case in point If someone's not breaking a drive then they're breaking a valve train or wiping out crank bearings etc etc , just hop from the drive forum to the engine forum and I think you'll get my point. Also you do have to throw in some boat owners trying to band aid a problem that should of been fixed correctly the first time. See if you've ever heard this scenario before. The technician feeling bad for the customer succumbed to the crying about the price of a set of gears to do the job right and gets blamed for the job coming apart earlier than expected in the end anyway. I'm sure quite a few techs here on this forum have been in that position before. Its a two way street here and as they say "good deeds never go unpunished."
Some Bravo XR's or XZ's are being pushed way past their HP design limits. For that I can't chastise the Mercruiser engineers they did their part. After all they do have product for the next horsepower jump, its called the NXT or a Speedmaster.
But again and again I still hear the Bravo bashing. Some aftermarket performance drive manufactures such as Imco or B Max and a few others have made some major improvements for this larger horsepower crowd. So if you don't like a Bravo go buy the product intended for the horsepower or task. They are a good products and help fill the dollar/horsepower gap. However these improvements eat horsepower and to be competitive in the classes of racing my niche is involved in the Bravo XR seems to be the best choice. Its the fastest and fairly reliable if built correctly. The Bravo XR's on my build and maintenance plan (minor gear inspection during the middle of the race season) seem to go two full race seasons before the gears finally come to what I deam "end of reliability". As a race only drive this can easily fit into a serious racers budget.
Now for the over 650hp crowd with heavier boats your mileage may vary. But as you know a few hardcore Bravo builders out there see some serious horsepower attached to their work. They're not stock and I applaud there persistence in building a better mousetrap. These are the individuals I'd like to share ideas with as "trial and error" are time consuming and costly.
So I'll wind up here by saying thank you to the ones that have sent emails with their observations

So I said my peace, I hope I didn't offend anyone, my niche is narrow and I'm not trying to solve the worlds problems. I just have a few questions for the serious minds on this forum and I have a few tools, jigs and observations that I made in the past that a few just may find helpful.
Thanks to all
Warren

Now back to the original questions :