Just 850's

Must be the No compromise boat? I should have put 2 and 2 together. Sweet boat just the last I heard it ran in the upper 90's. Fast no matter what though!

Trip Chief 850s. They are almost identical to my K/E engines I had in my 46. (different head mfg and cam profile)

Curious if the other mfg's you mentioned have the same build procces for the lowers as John does prior to assembly?

Like Sax says..... "Just PSI blowers" :lolhit:

John at the bravo shop might have some tricks for his lowers. Max machine worx, imco, all american drive survice, all claim they have special tricks to. These tricks still do NOT make xr gears bullet proof. XR gears are junk no matter what. NONE of this makes any difference if the MAIN POINT of the thread which is what is a economical way to upgrade his drives. Well the most economical way that gains him strength at the best price, and easiest would be a SCX upper and use his SC lower. There will be no negative side effects.

I don't know why you are bringing me into this but from my point of view you are BAGGING on my product. You claims of too much $ and sticking out the back of a boat some 12" makes you sound very wrong. Then arguing about it with members? Are you selling BMAX drives? If so, please state your position and please do not use my products as your spring board to attempt to make a BMAX look superior.

Bmax has been on the boat since April, gears have about 40 hours on them so far. Best mph so far is 133.8, Swinging a 34 pitch Maximus with a 1.30 ratio. Still have yet to really run it out as I'm still dialing in the setup with the hull.

28' scarab excel-

Datalogger shows 46 to 133.8 in 14.4 seconds, within 2280', with the throttle never exceeding 77%. So far I've spun a 34 pitch Maximus through a 1.30 ratio to 6200 rpms. The prop speed is so high that the blades spread out and forward. I started with about .700" clearance between the tip of the blade and the upper after we cut off the cav plate, and it carved almost .500" out of the upper with the tips of the blades. Working on finding a new prop to test out, something a little less prone to stretching...

I'm impressed, is your lower gear set a 17/19 then? The 15/19 1.50 gears I run used to last 10-12 hours with a little over 1000 hp and ft lbs of tq, I stretched this out to 40-60 hours or so by experimenting with different processes and settled on cryo/iso rem finishing along with premium synthetic oil (currently running the bravo shop stuff but was running Amsoil). I did switch to 1.36 lower gears that were cryoed, isoed and dlc coated this year and was eager to see how they held up but then I sheared off a billet vert shaft which destroyed everything in the lower including the case and gears so I am back to running the 1.50 gears. Im asking about your set-up because I am always curious in what works out there and what don't. I sheared off a billet prop shaft turning alot less prop too so you are doing pretty good, Smitty

Except the sc lower's still use merc xr gears which can and do fail under high tq and load, I would buy the scx lower too and turn up the power if possible to be really bullet proof, IMHO, Smitty:drink: