Knot 4 Me

I always let my drives drain overnight, including the oil in the reservoir. I've never had a buildup of gunk in the bottom of the reservoir doing it this way so I've never had to clean one out when switching from Merc HP to Amsoil. Someone mentioned 2 quarts? Maybe it has been too long since I used the old hand pump and quart bottles (have a 3 gallon pressurized container now) but I swear it was almost 3 quarts to fill a Bravo and the reservoir. I've been running this for years with good results but I am under 500 HP in everything I run it in.

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Black Baja

iTrader: (2)

I'm over 2qts with a complete drain and fill as well.

Borgie

iTrader: (22)

And you know what, it's not hurting a thing. So many people under maintenance their boats. Gear oil, even Severe Gear is pretty cheap considering. I say stick with what makes you feel good!

Borgie

iTrader: (22)

The amsoil AGM is awesome, however it seems to be well suited to boats under the 500hp range as you've stated. Anything higher and SG is the best candidate.

I know some guys add Lucas to Amsoil and other gear oils. IMO this is a terrible practice. The chemists formulate these oils with a specific additive package, and a product like Lucas or any other will only serve to interfere with said additive package.

By all means, do what makes you feel good, just know that plenty of data points to "most" additives being of no benefit, and sometimes detriment. If you research Severe Gear you will find it doesn't need any help from an additive...

MILD THUNDER

iTrader: (3)

I agree, except the cheap part. If I had a single bravo that only held a few quarts of lube, you betcha I'd be changing it quite often. But when you need a 5 gallon pail to change the lube on your drives, and another 5 gallons for your engines it gets a little pricey! Therefore I decided to run the Mystik gear lube. A 5 gallon pail is very reasonable. I'd rather change it twice as often, if not more, than running a more expensive lube, and leaving it in there a long time.

Side note, since I been running the mystik 85w140 in my speedmasters, I have eliminated the small amounts of metal fuzz i was getting on my magnets before. Makes me feel good!

MILD THUNDER

iTrader: (3)

You make some good points. I know you're up to date on your lubricants. My question is/was, regards to "application calling for". Lets say a Bravo one was designed to be used with engines making 525HP or less (just guessing dont know merc's max rating on them), but you are putting 700HP thru them. You are no longer in within the specified usage range, for that drives application. There are tons of guys out there running much more power thru their drives than they were originally designed for.

With that being said, my question was earlier this year, about going to a heavier lube, helping or hurting. Mine isnt a bravo, and I havent had oil analysis done, but, switching to a heavier oil, (and different brand at same time), has helped eliminate magnet fuzz between oil changes. I think for now, I'm gonna stick with the heavier oil.

However, If I was running a stock Merc engine, with stock drives and what not, I'd run what they recommend for the most part. I'd love to figure out a way to install some temp gauges on my drives. I think that be a cool pair of gauges to monitor while out there running hard.

Borgie

iTrader: (22)

Pertaining to "applications calling for" reference that I made prior, it's pointed to automotive/light truck applications mainly as Amsoils 75w-110 is technically closer to a 75w-90 in viscosity than their synthetic 75w-90 offering is. Hence 75w-110 is usually the proper viscosity in many applications.

Severe Gear is neither endorsed nor recommended by Amsoil in any marine applications, even though many have validated it through hundreds of hours of use. Amsoil only markets and backs up their AGM offering for this kind of application understandably.

I think heavier viscosity oil can in some applications help. The heavier viscosity oil usually helps not because it is just merely "thicker", it's more a function of starting out at a higher viscosity allows said oil to shear down to let's say a 75w-90 viscosity after use. You can see where this is perfectly acceptable, as most drives call for the 75w-90 oil, whereas starting out with a 75w-90 that's NOT shear stable, might put the oil at a final sheared viscosity of let's say 75w-60 for example... Now the oil is below what the design of the outdrive requires.

I'm not saying this is happening in your situation as UOA'a would be required to establish loss of viscosity through shear. I can however say with confidence that many synthetic gear oils (severe gear being one) are shear stable by nature, while conventional gear oil is not in pretty much every case. Changing it more frequently (conventional) usually makes this a moot point, unless the application is experiencing very high shear forces. In summation, there are too many variables to really say for example " I switched from 75w-90 to a heavier gear oil and now its wearing better". The reason I say this is, diffences between formulas of said gear oils used.

Metal in an engine or gearbox will by nature "shed" material until wear in. After it usually slows way down until the machinery either fails or is retired. Not doubting your findings to this point, just saying they don't say with any confidence that heavier oils are the ticket until further research is done.

MILD THUNDER

iTrader: (3)

Good info. In regards to your last paragraph, I see what you are saying and i agree. However, my drives, currently have 240 hard hours on them behind decent power. They are well broken in by now. Since Ive owned them, I've ran several different brands of lube, some conventional, some synthetic, (merc lube, amsoil, mobil 1 and some cheapo fleet lube) but all 75w90 until this year, when I switched to the 85w140 mystik. I ALWAYS got a bit of magnet shavings/fuzz on the drain plugs, until this year. I am happy to see that, or not see that I should say lol.

I dont think the heavy gear oil is for everyone. I only really went heavier after talking with some guys who had drives like mine, with bigger power, and noticed their intervals between rebuilds, were extended a bunch after switching to the heavier oil. They went from 75w90 to 75w140 amsoil. In my wet sump #4's, with 800hp a side in a 11k boat that sees quite a bit of extended hard running and rough water shock loading, I kinda like it. I have no proof besides the magnet inspections, that its working better though. I am however, gonna stick with it for now. Plus its red in color, and who doesnt like colored fluids. I run Valvoline Racing synthetic engine oil, which is blue in color. Red Type F trans fluid, and now red gear oil. Its all about the color man!

Any updates on the engine build progress? You ever get it finished up?

Borgie

iTrader: (22)

Well it's hard to argue with guys having tear down results with big power and using multiple oils, only to find the best for their application is the heavier viscosity product. I have always liked mystic grease, just never used their gear oils. In reference to the colors, bahaha, that's hilarious man. Why aren't you running royal purple motor oil?!

My project.... Oh boy where should I start... Well the good news is the short block is assembled and I have all of my parts including Holley MPFI from HAXBY. My wife and I bought a new build with an attached RV garage about 12 mins from the lake about two months back, so I have been busy moving everything, organizing, wiring the house.... It never ends man. And any time off I have is usually spent with my son or working on other people's boats. Speaking of, I sold the Mirage, so the last bit of fiberglass has to be finished off before the new owner can install his power.

MILD THUNDER

iTrader: (3)

Royal purple? I'd rather run a mix grape Kool aid and olive oil. :-)