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Need drive help
Im about to install three 555 ci. engines in a 42 cig, the engines r producing around 640 hp and 665 torque. it is a 1990 with wut i believe are original drives. What is the minimum drive i could run wiht this boat. Also what would be required in switching to some used #3 speedmasters(costs, speed loss). I am very easy on the drives, but i dont want to be breaking drives every weeked waiting to be able to use my boat.
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Re: Need drive help
what are your original drives? bravo or trs? # 3s will be tough to get parts for and you'll have to move the motors forward for trannies.
i dont think you need to go to #3s. why not go with custom built XRs or Konrads? you could probably get away with stock XRs, but you'll need to be easy on them. 20, 000 for drives,+ 6,000 for transom assemblies bravo shop, max machine worx, teague, billet can all beef up xrs for your needs |
Re: Need drive help
There is a new Xr coming out for the new 600 called the xxr. may be just what you need.
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Re: Need drive help
xxr? sounds like what we ALL need!!! :D :D
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Re: Need drive help
they are bravos, so is the only tihng i need to replace the drive itself?
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Re: Need drive help
Originally Posted by 375stinger
they are bravos, so is the only tihng i need to replace the drive itself?
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Re: Need drive help
If you are easy and smart you will be fine with your bravos, asumming no air time. I ran 950hp with bravos on a 42 fountain with very minimal problems.One gear set and a couple of shaft, Replaced with imco parts when broken and no future breakage. I did ease onto plane and drove reasonable, I did race just about every weekend though, 110 mph. Just my experience.
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Re: Need drive help
Well, you could take the chance, but examin your gimbles closely for any sign of stress or cracking, replace your gimble bearings. And I would have the drives torn down and rebuilt, just to be sure. all it takes is one bad bearing to take out the entire drive. bearings are cheap for piece of mind.
good luck |
Re: Need drive help
Stinger,
There are several options open to you. If MTI says he could make a set of regular Bravos live with that power in front of a standard Bravo on that big of a boat, I believe him, but also commend him!! 42' of boat is quite a load and I have seen people break drives in all kinds of combinations and if they are not careful they can break every weekend. Knowing what will break a drive helps. You can upgrade your drives to XZ or XR gears and upgrade the lowers to XR large shafts, or a mix of after market shafts that will improve their chance of survival. Proper set up and assembly is another important factor. I, from experience, would recommend upgrading to the HP gimble. That is an important link to the back of the boat and when it fails it can be violent. You can also buy new XR drives and the install kits for them that go into the transom assy. You can also look at the Bmax, Konrad, Arneson, etc. Depending on the condition of what you have, you can go several routes. Upgrades, new, etc. No one wants to toss money away, but done right the first time and care when driving and you can save money in the long run. IF someone has had good luck with this combination, as MTI says, you can have the same luck. I would suggest tearing down the drives to see what you have, then go from there. If you have some one local do it, find someone that actually works on High Performance drives and measures the case and sets them up for proper lash of the upper gears. Most just assemble per the Merc manual and dont really do justice to the end product. I hope this helps. If you have any more questions, fire away or feel free to email me. Dick |
Re: Need drive help
how much labor is involved in tearing down a drive, also if i were to strengthen the drives which parts would you replace, or if i were going to rebuild the whole drive what places will rebuild the whole drive with xr parts?
thanks |
Re: Need drive help
First off, you have to make sure your case is in tact. Labor to just tear a drive down and rebuild is probably around 350-400 each. if you need parts, that would be extra.
Basically, you would want to replace all your internals to XR gears. I believe the upper gears and larger input shaft will cost around $1,500.00 and I would recommend a Bravo shop vertical shaft. They run around 650 ea. but they are bullet proof. The lower gears and larger prop shaft will probably be around $1,000.00 So, total will be somewhere between 3 and 4,000 per drive. A good price on a brand new complete XR is around 6,000- 6,500 ea they usually run 7,500 - 8,000 New transom assemblies cost around 3,000 ea plus labor to install. The best price I have seen for a complete HP transom assembly was 2,795 ea. So, if your bravo cases are still good, you can upgrade to XR internals. If you shop around, you can trim those numbers quite a bit. There are quite a few shops that do good work on Rebuilds. the Bravo Shop Max Machine Worx Teague Custom Marine Dollar Marine TNT Billet and many more. |
Re: Need drive help
Bruce is right on with the numbers.
Depending on the condition of the upper cases, if they are good, you can reuse the input yoke and small ujoints. They are not a point of failue usually. Install XR gears and all new insides. Add a good top cap and you have a good upper unit. There are several aftermarket clutch shafts that are stronger than the Merc piece, but if you are easy on the drives as you should be, that isnt the weakest point. The vertical shaft in the lower is more prone to failure. I would put a good vertical shaft and the XR prop shaft and bearing carrier and all the parts in the lower. New bearings through out, start out fresh. I am have been building drives for over a year now and have had some big boats with big power to see what does fail when they are not concerned about breakage. If you would like to have an idea of different packages, give me a call so we can discuss it. It is hard to view the variables in text.. I am home after 5pm usually and you can give me a call if you like.. 616-335-8446. If nothing else, I can give you food for thought and an idea of what it might cost you to do what you want.. Dick |
Re: Need drive help
could i use the bravo x drives if i drove very careful, and i dont think im gonna be out of the water that often. i have seen bravo x drives for sale new around $4500, which woudl be less than rebuilding some 15 year old drives wiht new parts. The x drives are rated to 525 torque, i no that bravo ones are rated to 400 horse and can be used up to around 575 if you are careful. Do the x drives have as much room for extra power?
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Re: Need drive help
The X drives have the same lower componets as your bravo's. The only difference is thicker floors in the gears and different thrust bearings. You can upgrade your uppers to the X gears for around $1500. That gives you all new upper components. The X drive only gives you the better upper gears and heavy duty ujoints, so then you need the conversion kit to install them to the transom assy, another $100 or so. The XZ has the good lower components added to the X drive.
Go to http://go-fast.com/mercruiser_bravo_sterndrives.htm and they explain the differences between drives. You can mix and match components and build a better drive than the XZ and have more room for margin, like your talking. The x drive wont be much more than you have. Your best in my opinon to build the best drive you can in your situation. The Bravo drive isnt very happy on the bigger boats. Yes you can make it live, but the heaviest duty bravo will last longer. I have build several XZ style drives and the guys around here can make them live. They prefer them to the XR gears that wear quicker than the XZ. But if you need the strength of the XR gear, then you have to live with the 200-250 hrs life expectancy.. Dick |
Re: Need drive help
Dick,
I replaced my entire B1 when I added a B&M 250. At the time I researched it I came to the conclusion that with 620 HP in a light boat the XZ may live longer. This was from discussion with several people who said the XR gears wore quickly and developed a great deal of heat. That along with some rumors that the XR could suck up a fair amount of HP compared to the XZ drive led me to believe the the HP went to creating heat since the bearings and lower were all the same. If I had the opportunity to swap gears during an inspection tear-down should I consider going to the XR gears? |
Re: Need drive help
My xr gears at 135 hours were starting to scallop,they had about a .004 thousandths ridge/indentation on them. Max machine said i could probably run them another 100 hours from my description but i changed them for insurance against breakage. Pushing 750 ft lbs( give or take a little) of torque with 30 pitch prop im 4500 lb boat,Smitty
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Re: Need drive help
Since I've been on that boat, my suggestions:
1) Use regular bravos and keep replacing them every time they break. Then when you're tired of that, sell the boat. They'll only have to live long enough for the test drive then. 2) Get a basket full of money and buy new HP gimbals and buy new XR, ZX, XYZ, whatever....drives, only to discover they're still bravos and thaey still break. 3) Or if money's not a problem, upgrade to SSM IIIs and never worry about breaking stuff. The added weight wont have much effect on that hull. 4) Or............... for that same basket of money that it would cost for the bravo upgrade, or less, you could do what I would do. Buy 3 used SSM gimbals, rebuild them yourself. Glass and recut your transom yourself. Buy 3 rebuilt SSM IIIa. Then find the rest of the mics parts (ie trannys, driveline, steering) used and rebuild/install them yourself. You'll end up with a reliable boat that you fully understand how it's rigged and how it works. Any time you throw a lot of new parts in a boat more than a couple years old, you end up with a boat that costs 2-3X what it's worth. Gary |
Re: Need drive help
i think ill probably keep the bravos and wait for them to break until i get the boat done, and will see how it goes this summer. by the way, did the boat sink in salt or fresh water, can you give me any details please?
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Re: Need drive help
Bad Dog,
If you are not having any problems with the XZ gears as far as beakage is concerned, I would stick with them. I have several drives out there with the XZ gears and they are doing fine. Wear is not an issuse with them persay (sp). But when they do go, they go. It is so hard to tell what torque is going to let the bravo live in certain situations. My friend is running a standard Bravo drive in a 5700lb boat, with a big motor, I know is over 800hp and the drive has lived for 5-6 years with on rebuild. He is good on the sticks, but still!! Gary, Your right, it sometimes is easier to just swap it all out.. but I think a new boat is a cheaper route to go.. then get the #6's! But an inspection rebuid on them is not cheap either... Moral of the story.. boating costs!! Enjoy it if you can.. Artic, scallops in the pinion gear on an XR is an indication that the gear may be soft. I have heard pro's and con's on the subject, but finding a gear with the ridges and then replacing it, then no scallops.. tells me something is soft??? I think you did good replacing it when you did.. that fine metal in the drive oil is very hard on the bearings!! And when there is metalic glow in you drain lube, tells you if it is wearing, I believe. So clean oil means good things.. Stinger, You make the call. What ever you are happy with. These are all suggestions and need money to go forward with. I am just passing on my limited experience. I have maintained a 50' Hustler with 575's and the XR drives would break fairly often. Then it seems like they quit failing so fast. I think it was the man on the sticks type of deal. So you can make them live, but an inspection tour will let you know what condition the bearings are in etc. Then if you did want to upgrade, you could make a decision. I am very flexible with parts and can put together what I think would be a sensible package. If you so choose to do that.. The more you talk to people the more knowledge you will gain to make that decision.. I hope this helps. Dick |
Re: Need drive help
Originally Posted by Mr Gadgets
Bad Dog,
I have maintained a 50' Hustler with 575's and the XR drives would break fairly often. Then it seems like they quit failing so fast. I think it was the man on the sticks type of deal. So you can make them live, but an inspection tour will let you know what condition the bearings are in etc. Dick There are several shops out there that will do a good job on the drives. I have had Mr. Gadgets/Dick go through/rebuild my Bravo XR One drives (32' A/T with twin 680hp engines). He has an elaborate set of micrometers capable of being able to mic just about any wierd angle that you can think of----and he is not shy to use them! He mics just about every part on the drive for proper blueprint, and assembly. |
Re: Need drive help
My understanding is that it took on water at LOTO. But before it even went under, at the owners dock, a salvage Co took it! They assessed an ourageous price on it and expected the owner to pay the salvage fee, a percentage of assessed value. Anyway, ended up in courts, very messy.
But the boat is VERY heavy and I dont think the original 540s were easy on the bravos. Big boats and bravos dont mix. BTW can you tell I'm not a bravo fan? :p |
Re: Need drive help
Kaama,
Thanks for the plug!! I am slowly moving into the new space, gearing up for the summer rush! How's your project coming any way? Gary, You are right.. big boats and bravo's is a compromise for sure. It sounds like Stinger wants to give it a try anyway. It sounds like there was a history to the drives ability to hold up. If that is the case, he could be in for an expesive learning curve. But there are things that can be done to help. I have seen shafts break, and teeth break and towers and all kinds of damage. I do believe you can build a drive that will live for a while any way, depending on driving habits. If it wears out, thats not too bad, but if they break all the time, well the money is better spent on something bigger and stronger than the bravo. Any way you look at it.. three motors, big boat, will cost big money to maintain. No getting around it. I think what Stinger is looking at is a starting point. Check the drives out to see what condition they are in and hope he can make them live for a reasonable amount of time. That 50' Hustler is keeping drives on it for some reason now, and I dont think it is because of the build quality of my drives, I think the guy is doing a better job of driving it. It does have XR's on it, but no after market shafts, so things can be improved some. I dont want to disillusion anyone about a miracle Bravo drive, but they can be setup to do better than they are in stock condition. If Stinger's boat has regular Bravo's on it then he does have room to improve.. Will it solve the problem?? Without a good history and intial inspection we wont know. Stinger, if you want to give me a call and talk about this, I would love to give you my .02.. Like I said before the more people you talk to about the subject the better idea of who to pick for your drive man. I personally spent a lot of money trying to find a good drive man.. and decided to do it myself. I have had alot less trouble with my standard Bravo with XR gears in it since I rebuilt it and set it up!! The next time I need to replace my XR gears because of wear, I may just step back to the XZ gears. I will cross that bridge when I get there.. Again, I hope this helps you in making your decisions on how to proceed with your new boat.. Dick |
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