Imco extreme advantage
 

Does an Imco Extreme Advantage 1998 year drive have straight cut XR gears or spiral Bravo 1 type gears?
How does it compare for strength over a standard XR?

The IMCO gears are straight cut and a little bigger aswell as the clutch and bearings.

I will let you know about the strength. I blew one of my bravo 1 uppers and got the old style imco. I am running over 700hp per so we will see:evilb:

It would be strange if they used the Bravo 1 gears but maybe the XR wasn't out yet.

I believe they are Bravo style gears with thickened floors like the x drives have.

In 98, I dont believe the thick floored gears or the XR gears were out yet. It is possible it has the Imco modified thin floor gears.. They welded the floor and bead blasted and reheat treated them.. The X gears are a better gear, but they all have the same helical cut teeth..
Correct me if I am wrong, but I think all the X stuff came out in 2000?

Im not exactly sure when the x stuff came out (I want to say 2001) but I can tell you that as Dick says,a 1998 imco is going to have the old thin floored gears that are maybe welded up then then ground back down as that was the best you could get in the 90's in a bravo,Smitty

Hi Dick.Lowers are going just great.Next race 5 weeks away.So the 98 Imco isn't going to be a real strong upper thats comparable to an XR?Thanks for your reply Smitty.

I have the IMCO extreme's with the ibeam cases. They break. Just XR gears. I'm sure they are newer than what you are looking at.
I think the problem is with the gears in general. Personally, I think the material is not the best & no matter how strong the case, the gear is the problem.
Someone needs to build a "real" gear with "real" materials.

According to the experts the later XR gears are much weaker than they use to be.Easy up and real easy down isn't working.I just recently tore a tooth that destroyed a new upper unit.
Dick who posted previously feels the new IMCO scx is the way to go.Just hard to get around the initial $.
Thats the way i'm headed though.

SSM #6 drives my friend.

The only way to fly...

Yup. Just hard to put them on a boat under 35' without some major surgery & major expense.

Not to mention, on a boat like mine (28ft w/ twins) all that weight would damn near sink the ass end.



Darrell.

Has anyone ever tried to sell an XR Gear set that was not Merc

Not sure, but it would be interesting if a company like Weddle (sp?) would come out with a stronger version. I know there is a market for them.


Darrell.

I think there's a market also. Imco, Teague and Max are all using Merc XR gears in their "beefier" drives. The drives are upgraded all around the gears, but the gears still break. I recently say an Imco SC with one tooth snapped off like someone posted before.


How much would you pay for a gear set with a 1 year warranty?????????????? I know I'd pay a little extra.

Me too.There is a post on here about outdrive gears.To cut it short what makes a good gear?When you think about it, it nearly always seems to be gear failure.What would a Titanium gear be like?

What does a #6 weight?

IIRC, it is like 520lbs if you include the whole transom assembly.

Not really sure. But I know that Weddle has the ability to improve on the stock Merc stuff for sure. It would really be interesting to know if anyone has contacted them about this. Merc charges about $1600 for XR gears, So ya know there is money being made. Here is something interesting. My Bravo drives have been buily by Max Machine Works (MMW). The have the steel towers, and steel floors, IMCO shafts and such. Basically everything you can do to a Bravo. BUT They installed the Helical upper gears. Not sure why, but seems they may have known something??? Anyways, it seems like a stronger( both material and design) aftermarket XR gearset, would be a very profitable venture for a company.

When did you have you're drives done by MMW?
It is strange they didn't use XR gears unless there is a reason for not putting them in a Bravo 1 case.
The early IMCO's had alot of failures if you read the posts on here.

I'm working on designing a new upper gear set for an XR drive.

Should know more in a few weeks.

Straight or spiral?

Well hurry up & I'll test them to destruction.:lolhit:

They will be the straight gears as used in the XR drives, but hopefully will hold up to at least 800 hp.

And I will be testing them personally with a big heavy boat and 800 hp and 900 ft lbs :eek::eek:

Smitty,the current XR gears are forged? and made from what sort of metal?
Is/will a billet gear be stronger?
Who do you think in your opinion makes or modifies the best currently available gears?
Does getting "more tooth contact"like the bravo 1 spiral gears as oppose to the XR style help?
I just wonder if the Bravo 1 failures related to HP are attributed to the gears or is it the towers,shafts etc letting them down whereas if a reg Bravo1 was given all the upgrades the XR gets with a huge set of spiral gears.

My biggest challenge is to get a stronger gear in the same space as the current gear occupies.

Helical gears would be stronger, but the teeth are to narrow now and there is no room to get bigger.

The current rash of failures are due to the quality of the metal used in the gears along with the fact that they are 2 piece gears. That hub that holds the brass ring is welded on.

Billet gears might be stronger but they cannot be CNC'd right now because of the hub.

That's all I can say for now. I am on a mission to get something made that will hold 800 hp and last more than a season !!!

Go Smitty... GO!!

If you can get this project accomplished...
you will sell a ton of them.

Chris

Not Smitty but I'll have a shot at answering.
Replies above in red.

Also in the report I commissioned, FWIW,

Comments on

"Material Identification of Damaged Bevel Gears'

'Two damaged gears, one a straight bevel gear and the other a helical bevel gear..were submitted for metallurgical examination primarily for material identification purposes.'

'Metallurgial examination has revealed that the bevel gears had both been manufactured from a low alloy case-carburising steel....
Cross-sections of teeth taken from each gear showed that they had been case hardened to an approximate effective case depth of 1.1mm,ie minimum case depth at which the hardness remains above 500HV. Both the material and heat treatment, including the case, is considered satisfactory for this application and not likely to have been contributory in failure.'

Steve

To answer the OP question,
Year 2000, serial # OM100000 and above was when the X, XZ and XR were introduced.
So a 1998 model would have the old style gears, ie, helical bevel, thinner floor, different bearings and small U-Joint yoke, unless, of course, it has been upgraded.

Steve

The boat is a 98. I think the drives were originally done in 2000 or so By MMW. They were refreshed in 04 before I purchased the boat. The drives have held up very well behind the 800's, but... the boat isn't very heavy. I do run 1.36 gears and 36p Bravo props, so it does see some serious stress. I did have one issue last year, but it was due to a broken top cap. Knock on wood..... they have been very reliable for me.


Darrell.

The problem I see with building a gear set,either upper or lower,is when you have a gear cnc machined vs net forged or near net forged the root strength is signifigantly LESS so any gains from a superior alloy will be lost as far as root strength. I spent alot of time and some money trying to get lower gear sets built until I found out unless they are forged there will be less root strength. I think to get any where with the lowers you need to spend 50,000$for a short run IF the 5000$ protypes held together,with the current market it is out of the question. As far as uppers you could easily spend 250,000$ getting forging dies made,prototype gear sets,r&d time, a small production run,etc,etc and still would they be superior to the current merc stuff and how many years would it take to sell enough of them to ever re-coup your cost?,Smitty

Totally correct

and as was shown in the 'Konrad' post, even they are using Merc lower gears.

Steve

My goal is to make the upper gears any way possible so that they are stronger than what Merc currently offers. The new stuff from merc is crap. I know I can get some forged gears made that are stronger and not 2 piece like mercs are.

A Merc gear is getting evaluated right now.

"A Merc gear is getting evaluated right now."

I've heard there being made from used TRS cases,thats what the one i broke looked like anyway.

Getting confused with 'Smitty' and 'Articfriends' here....anyway,

If you read what I answered in post 28, when I had an XR gear and helical gear analysed on October 19 2007, the XR gear was from a 2007 box, OW and up, the material identification debunks the 'new Merc crap' and even goes so far as to say the material is satisfactory....not the best but...

IMO, you would need access to the Mercury dies and have the gears forged from a 'better' material.

The 2 piece gear bit, I have never had a thick floor gear fail there unless it had a broken tooth.

I am not a Merc dealer or lover of their policies and would appreciate them supplying a higher quality gear.

The only way I see it happening is from Mercury, so unless you can convince them, break out the bandaids.

Steve

Steve

Thank you for your input and comments !!

I am reverse engineering the gears to aid in the making of dies. In my area we have seen more failures of the most currently manufactured gear sets. I feel the material used is sufficient enough for say 500hp, but of course most of us have much more and I am sure if the gears are made of a different or better material, I will get what I am looking for.

And also I keep breaking teeth off at the root along with the other guys as well. I feel that the air gap behind the tooth that is there since the hub that the brass ring screws onto is fusion welded, is an area of possible weakness that I plan to eliminate with my gears.

I guess we will see what I come up with.

Thanks again !!!

Smitty,

Good luck and keep us posted, with good results and a reasonable price you will sell heaps.

Steve

Smitty any progress?

Wouldn't it just be cheaper to buy a IMCO SCX upper.. with the 5"+ gears.. and be done with it?

They are about the same cost as replacing three sets of upper gears... and IMCO is reporting no failures to date.

Chris