Re: Poll: Do think think a SE106/SE116 will handle more than 300 HP better than an Al
on a lighter faster boat, should be fine.
The only drives I've broken have been my fault (one water intrusion, another I didn't do a good enough job checking ujoints apparently). I've been running various combinations of merc and sei uppers and lowers for the past year or so behind a 400+ horsepower 383. A fair number of folks here do it and very seldom have problems. I'm far from easy on stuff personally. I will have cloer to if not over 500 horsepower when I put things back together this time and know of none guy on the river that's running close to 90 with a blown smallblock in front of an alpha drive...
My understanding is that even more of a help to the drive temp is running through hull exhaust so that you're not heating the hot exhaust gasses.
run good lube in it, check and change it often.
why would I run an alpha instead of a bravo? the main reasons are above, most small boats that you want to "overpower" will come with an alpha drive and so it's pretty major to change the whole drive assembly out. especially when it will be slower with the bravo drive or require more power to hit the same speed. bravo is a little heavier, has more wetted surface area and a little more mechanical loss than an alpha. and you can afford to frag a few sei drives for the cost of even a used upgrade.
the prop issue really isn't one. in the extreme of a 32" prop, you would have to be running over 100 mph with a 1.5 gear before you need that much pitch.
With 400 hp, we're talking more like 60s or 70s depending on the hull and the engine. For the standard gear ratios of 1.81 - 1.5 to 1 you're likely to wind up, that corresponds to 23" - 29" props. there are a lot very well designed props in those ranges that work well on an alpha drive. many available for very reasonable used prices.
I've now gone through prop selection on my current 17 1/2 foot, about 2300 pound 400 hp 383 boat with 1.32, 1.47, 1.65 and 1.81 gears and although it was fastest propped right with the 1.81 gear, have had it well into the 70's with each of the combos. Some of the props that have worked well include (and depending obviously on the gear ratio), 19" predator, 21", 23, and 25" laser 2, 22" solas, 27" mirage, 27" and 28" mach 4 sterndriver, 29" hydromotive intimidator, etc...
a big caveat to this is be safe. We had a collision here last weekend. I knew both of the guys from around. one of them died. Once you start going much faster and pushing things to the edge, make sure you think aobut things like using the safety lanyard and kill switch, having at minimum a steering stabilizer on your drive incase you break something (like the gimbal or steering assembly) going fast.
the accident this weekend has me rethinking some things in my set-up that's for sure... the collision was between an allison and an outboard checkmate... the guy in the allison didn't make it.
on the original question, I don't know... I do know that the upper gear sets in the sei drives i've had are pretty beefy and seem to hold up very good to wear....
just my personal experience and observations...
OH, and I should add that at least with my little boat, any of the above gear ratios when propped to put max hp near wot will easily pull skiers out of the water with less than half throttle... or stand the boat up in the water if you give it enough throttle from a slow start... have fun!!
