Big Block Billy

Give Kurt ( BIGGUS ) a call and he will work with you...
He came out twice from Maine to Long Island to run the boat and help us get things right. Do you think if you bought 2 speedmaster #6 , that Merc would send someone over to help iron out any problems at their expense(WHILE GIVING US HATS AND T-SHIRTS! ) ! I really doubt it !!!
Once you have been around the Konrad drives you will kick yourself for playing with anything else ! They are that good !!!

Strip Poker 388

But with the Konrad he will have to change up steering,add the transmission which adds weight,do you have to move the motor forward?Tail pipes? also what is it warrantied to hp wise?isn't the cost in the low $20.000.If Smitty blows up drives a few times a year he fixes it him self at prob max cost 1000.00 .I think Smitty is a good bit above the HP rating

articfriends

If I had it to do over again I would buy a Konrad drive or b-max and re-rig my boat but its not in my non-existent budget at this time.I haven't had a max worx part such as a shaft or a upper failure in 3 1/2 years though,2 seasons with 950 hp and 2 with 750. I have spent about 200$ on gear oil and 500$ on bearings, lower gears and a couple of different types of metal treatments this season plus my time which I have had abundance of since losing my day job in june. When the lower gears start to chip up I start seeing metal in my oil and tear drive down,I have never been dead on the water from it. I have almost 20,000$ wrapped up in the initial purchase price of upgrading my drive and my sparemax worx drive that I will never get back out of them but my spare hasn't been on the boat this season and was only on boat for 1 week last year while getting a set of lower gears from Mr gadgets so its still like new.Luckily I have never blown a drive to the point it was worthless,the housings on my drive are going on 7 years old. I will be continuing my lower gear experiment and will NOT be trying to turn a 5 blade prop again as its pretty evident it stresses my drive to the point of almost instant failure. There is good info to be had from what I'm experiencing-on a single v around 900 hp at the prop shaft a 5 blade prop is going to guarantee drive breakage from a upgraded bravo but if a set of lower gears can be made to hold up and you stick to labbed 4 blades you can easily go 200 plus hours as I have done on the rest of my components,Smitty

Big Block Billy

I investigated the Konrad option but didn't want to invest 20,000+ in upgrading my boat to Konrad. The boat just isn't worth it...
Konrad makes an extension box that houses the transmission and everything inside the engine compartment is in the same place and actually exhaust and mounts and everything else can be used from the Bravo setup.
I actually went and bought a Bam 1000hp rated Cyborg tranny on ebay !
With the extension box the boat behaves like a larger boat and lifts the boat higher, kind of making up for the added weight of the heavier drive and transmission.
There's nothing like the smooth operation of the shifter with the tranny ,as opposed to shifting a Bravo.
I ended up buying an Imco drive and a stainless gimbal ring, Hd helmet, etc.
I figure I can easily take the 540 out and put a stock 454 mag and a Bravo drive if I am ever going to sell the boat.

mcollinstn

cryo treat is not a HARDENING process.
It is a process that is designed to even out the molecular bonding in an alloy.

Each alloy has a different cryo profile just as it has a different heat treat profile. Cool rate, soak temp and duration, and warm rate are different.

The whole goal is to even out the structure cause normally an alloy has a mixed bag of molecular bonds in it. We all know a chain breaks by its weakest link, and metallic fractures all occur at the point of a misbonded molecule. It's just like mixing Ovaltine in your milk. Normal method ends up with floating clumps of chocolate dust (I like the malt flavor best). Think of cryo as something that slows down the electrons and allows them to hold hands better, then when it warms back up, they are still holding hands.

You can cryo before heat treat, and then heat treat.
You can heat treat and then cryo.

the whole idea on cryo is to eliminate the weak spots in the structure. Not to make it hard.

mc

articfriends

My understanding was it would stabilize the grain structure of the base metal below thae hardend surface. MC-let me run this by you for your professional opinion and advice in case you didn't read the whole thread. My boat has a 900 plus hp/ft lb tq motor,with the exception of recently running a 5 blade prop,I am getting over 200 hours on the shafts and upper gears without any parts breakage/catastrophic failure. The lower gears after 20-40 hours break thru the factory surface hardening and start to get chipped up putting metal in my oil. They are a 8620 near net forged steel with a surface hardening of about .010 to .015 deep. When they start to chip away they get porious little craters in them down to the softer base metal. I had them rockwelled and the surface was at about 60-61. I sent a set thru a heat treating process to deepen the hardness thinking it might help there life. After 17 hours they were chipped up exactly the same as the oem's,only difference was the little craters were much deeper because surface hardness was thicker. I next had a set deep freeze treated then surface finished,I'm pulling them out today after shearing off a different component this weekend from overloading drive trying a 5 blade prop that loaded boat very hard so I'm not sure how they are holding up other than I haven't see any metal in the oil yet. Other than a new gear from a stronger alloy or bigger gear thats helical cut to spread load on several teeth at once instead of just 1 tooth do you have any suggestions? Maybe you could build us some gears out of a super alloy like a 9310 and make a small fortune ,thanks for any input or advice you may have,Smitty

SB

Run more rpm , ie: shift that same power to a higher rpm Time for each tooth being loaded is less. Gear manufacturers actually have this as part of their calculations.

Big Block Billy

Bam has a treatment for gears.
I believe they shot - peen them too.... BBB

mcollinstn

smitty,

Sounds like a point contact lube film failure. If your surface is 60+ then that's about as hard as you can expect without really bizarre things like TiCN - Titanium Carbo Nitriding (which might actually be a good surface treatment to try). So your surface hardness is substantial. If we assume that the underlying root material is NOT deforming (but we know that it IS), then the spalling and flaking HAS to be coming from lube film breakdown. If we add the known deformation that is taking place, then while it is still a lube film breakdown, it is not automatically the lube's fault, because the deformation is allowing the load surface to minimize to a smaller area of load application. No lube can live at a point contact.

So we have fluid lube (gear oil) and surface self-lube (smoother, harder, and less friction) do be concerned with.

You are already running the "proper" fluid lube.

So how much do we rely on IT, and how much do we rely on self lube surfaces?

If we rely on the fluid, we need to keep microporosities in the gear face to "transport" the lube into the contact area. Mirror polishing is counterproductive to this. If we rely on surface self lube, then the more polished it is, the better off we are.

Problem #1 in micropolishing gears...
You'll never polish at exactly the correct geometry for even load application. This is why gears with a little bit of runtime are better to start with. BUT gears with low power runtime will not polish in the same manner as gears under high power (the deformation comes back again).

there's just no perfect solution.

My guess?
Start with good forged gears. Have them inspected.
Cryo them properly.
Run em shimmed properly a few hours and load em pretty good once.
Heat treat them for surface hardness.
Send them to a tool coater for TiCn.
Cryo them again.

Cross your finger, toes, and buttcheeks.

mc

crazy canuck

Smitty I've been following this topic since it began I have two TRS drives sitting on the garage floor with new gears ,bearings etc just waiting to go back together antisipating your findings .I agree with
mcollins about the cryo treating ,being a machinist by trade i have worked with all types of exotic steels, different types of heat treat
procedures.I once worked for Rolls Royce(Parsons) steam turbines they used alot of exotic steel they would import from England .They used to Nitride alot of their components ,you can't mess around when dealing with a Nuclear powered steam turbine !I now work with Dana heavy metal stampings they nitride all their forming dies for wear and it works .Since you have become the out drive " Ginea pig" try nitriding the gears after the cryo and the iso-rem finishing .
Mark