Randy Nielsen

iTrader: (4)

audacity, I would like to actually see if & how much water they actually pour on the drive. Changing direction of moving parts especially with a lot of hp does tend to build heat. Don't the bmax uppers have water jackets all around the upper gearset? I would think that would help more than spitting some water on the top needle bearing cap.

audacity

we did a LOT of testing with instrumented drives and data acquisition systems. cameras too! when driving at moderate speeds where the shower was providing water, the oil temps were very low anyway. hi speeds the shower had no water going to it. at 70 mph there was no water and the temps were ok...at 90 still no water with very hi oil temps! to have water flowing to drive at top speed actually slowed the top speed and the temps were not measurably cooler. we have even discharged engine water on top of the drive.

as a side note using a shower produced staining on the top of the drives and made it difficult to clean.

in the end the area where the pickup on the showers was removed for increased performance and the top plate with hole in was great for removing the drives! which i rebuilt drives EVERY TIME they were used, even if they only had 10 mins on them!

while i have yet to take temperatures on a BPM drive (Arneson) that has let than 2 qts in it and sees no water, spinning outrageous speeds with 2500hp going into it! the oil always looked good coming out.

Randy Nielsen

iTrader: (4)

I would take it then that with no pump in the drive the oil in the lower half stays cool because it is submerged & the oil in the top burns up because they can't really intermix with only 1 lube hole connecting them. I've never seen a #6 apart do they have some kind of pump assy to move fluid around? As far as cleaning goes I've almost given up because I have yet to find anything to cut through that baked on crap

audacity

goto home depot and get yourself some muriatic acid and mix it in with some water...stuff will fall off! it won't hurt ya but does burn like a biztch in cuts or a hangnail. lol

if ya wanna be nice to your drives...use a 6 blade rather than a 4. there is a significant reduction in vibration with adding blades.

change your oil often, not because it's bad but it will give you a chance to see whats coming out.

with every oil change your top and back caps should come off to have a look. even excessive wear can be fixed by flipping the gears and using the other side. much cheaper than blowing up a drive!

Randy Nielsen

iTrader: (4)

Been using muratic acid for years & the crap in the missouri still hangs on I have even soaked my props in the stuff & it is still a hassle to get everything clean. As far as gears go I read someone saying they just swap the drives side to side every year to swap the load on the gearset, plus don't you have to disassemble & reshim to flip the gears? I don't have all the special tools needed to set up a bravo, I do however agree that changing fluid often is cheap insurance to catch a problem before self distruction happens. What are your thoughts on the side to side swap idea?

audacity

no special tools are needed to pop those caps and take a look. and it's highly recommended...and an ideal way to fill the drive with oil.

i would not just swap drives without having evidence to support that decision. you could create more problems than you think you are doing good! ....but really if you see wear patterns on gears...what type is it...if the gear teeth are hammered then the chance of snapping it off running the backside is too great. some fretting, maybe ok, but the question is where is the material that came off and what else did it do?!....

people that know how much i've done with bravos always expect me to say that here are all these problems with the drive and here is what you have to do to fix it....truth is that almost always some small part would show VERY early signs of failing in a perfectly working drive. swap that part out and you're back in biz.

hey,,,drug boats are on discovery right now. lol

Randy Nielsen

iTrader: (4)

I'm watching the drug boat show right now. What I was understanding about swapping drives pertained to the load on thecase floor in one direction & loading the top cap in the other. As far as the thrust washers & needle bearings would that be the first place damage might happen that would be obvious? As far as the gears I broke a couple off another drive last year but caught the noise & shut down immediatly,disassembled upper & lower to clean & inspect for other damage,fortunately did'nt found filings or anything but am reluctant to just swap out another gearset without being able to check clearances & backlash,pinion depth those are the tools I don't have.I will not take my boat to any shop in the Omaha area because I used to deal with them with my own shop & they just want hang parts inflate prices & give you the once it leaves warranty void attitude.

audacity

u can always email me with question [email protected] . i'll b more than happy to tell ya what i know, if it can help ya out!

cheers mate

thirdchildhood

iTrader: (6)

Best answer!

waconda

Can you tell us what brand of showers you tested and on what kind of boats and the X on each of the boats tested. Were these stock applications or not?
Is there a thread on this forum or somewhere else you can point me to it, I would like to see the videos at the different speeds.