high hp bravo 1 questions

[weekend@burnies]

going to run 625 hp thru a bravo 1
If you have done it let me know your experiences
any mod suggestions would be appreciated
it's a 1999 b1
thanks

[Ratickle]

How big of boat? Hull type and weight.....


I've done it, 633 HP through a B1, but on a 2450 lb boat with a semi-vee, not a deep vee.

[weekend@burnies]

27' fountain think its around 4900

[Ratickle]

You're really close on weight...

http://www.boattest.com/boats/boat_video.aspx?id=275

[weekend@burnies]

so with 70 gallons of fuel all the oils and four passengers and cooler prob around 6000-6100 lbs
I know it's going to be pushing it to the limit and it won't be if it will be when .
just wondering how long others have gone.
hoping to at least get a season out of it .

[Ratickle]

We'll get some more input, but my guess is it better have the best oil, Bravo Shop maybe. A really good cooler, and a guy that's pretty careful on the sticks.....:)

[weekend@burnies]

thanks ratickle

[Bilgerat]

Make it live by bolstering the top end, Need to really put a goal and a budget together before you can answer this question. I have personally ran a twin 900+ hp boat on stock spiral bevel geared uppers with IMCO bottoms. Did it break every now and then It would tear up the small bearings in the top between the gears. But Most don't beleive it.
Anyhow if your not chaning the gears to XR or even if you are, Have Max Machine Worx install their big tower in the case, and use their billet 2" top cap, with 7/16" studs. This along with the solid pinion shimming kit will keep your upper gears aligned properly under higher hp, and that's the big key, they also have a suggested concoction of oil that we have used with decent results, but Merc HP gearlube works great as well. Even if you choose not to get the tower installed, at least stick their top cap on and do the pinion shims. You said its a single Fountain is it turning a Left handed Wheel?? they often do, and if it does it is driving on the gear that is against the top cap, very important, to get some rigidity in there and not let the gears deflect from one another.

[Ratickle]

But do you think he could get a year's worth of use out of it the way he has it now, or does he have to make strength improvements to get it to even last a year in your opinion?

Why do Fountains turn left hand rotation? Most single boats have right hand rotation to offset the engine torgue....

Left-hand rotation propeller is one that will move a boat forward when it turns counter-clockwise when viewed from the back.

72718

[Bilgerat]

Let me start with I do generally like Fountain boats. Usually a single left is to offset something that is amiss on the bottom. for instance a 29' Profile (old ones ) always came with a single left hand wheel to try and make up for the Hughnormous hook on the starboard side, which was just past the mid ship rocker and next to the smaller hook on the port side. I have just noticed that most of the Single Engine Fountains I have seen are single left hand wheels.
The length of time left in the drive I would say can't be assumed. One has no idea what the inside is like now. I would probably have the thing inspected and know wether or not you are using a nice good drive or a crummy wore out one to start. But definite places to start on upgrades are good coolers, good lube ( fresh clean ) and then let the upgrade options start to spill in. Again, budget, and goals. You know XR gears are nice, do you NEED them? Not Necessarrily. Most of the tore Up drives I see are all XR Geared, but also mostly on heavier boats with even more power, and sometimes attached to a throttle arm driven by Bud Light and the guy in the boat next you. The guys that don't have trouble have quality sensible upgrades, good driving habits and do routine maintenance, including an occasional tear down to catch wore parts before they break.

[John P]

going to run 625 hp thru a bravo 1
If you have done it let me know your experiences
any mod suggestions would be appreciated
it's a 1999 b1
thanks

This can be done with a few upgrades as mentioned but the drive must be set up in a different manner to be able to handle the power. ( this is not in a merc book) One more upgrade I would do is a HP clutch shaft that will also accept the longer bearings in the case and cap.

[C35]

sometimes attached to a throttle arm driven by Bud Light and the guy in the boat next you.

.

funiest thing ever posted on a board- ever. anywhere.

this is goin on a tshirt for sure.

[weekend@burnies]

thanks for all the input, I believe it's turning a rh wheel . it's been a few months since I've seen it.
this project started due to a scorched bank of cyl's in the 454 mpi .
looked all around for a 525 found a fresh rebuild that's been warmed up to 625 . the budget ceiling is near but can be raised .
the main goal was to get it back on the water, but projects tend to grow haha
would love to put one of your drives on John P but thats looking more like next year

[John P]

We make HP shafts for Bravo drives also.

[Ratickle]

Okay John here's the question:


If you were on a tight budget for the current year, had the 625HP engine installed...

What is the minimum you would do to the outdrive to get through season #1, before sending it to you for season #2? (Assuming you would be cautious on the sticks completely through the first year).

[John P]

Okay John here's the question:


If you were on a tight budget for the current year, had the 625HP engine installed...

What is the minimum you would do to the outdrive to get through season #1, before sending it to you for season #2? (Assuming you would be cautious on the sticks

completely through the first year).

I guess if it where me I would take the drive apart and do an inspection on the internals and replace as needed and then put it back together along with hard shimming the upper pinion bearing set and setting the back lash to a clearance that would support the 625 hp. And then use a gear lube that can handle the heat of a bravo and I would put on a Simrek drive shower if it fits with the current steering. This is as basic as you can do with out spending a ton of cash.

[Ratickle]

Do the early B1's use shims? Weren't there some that didn't use shims? Or am I thinking of something else?

And then send it to you as soon as it can get into the budget.....


I can't believe it would hold up to hard driving at all.....

[John P]

Do the early B1's use shims? Weren't there some that didn't use shims? Or am I thinking of something else?

And then send it to you as soon as it can get into the budget.....


I can't believe it would hold up to hard driving at all.....

You can use the newer bravo parts in older drives.
As far as holding up there are a ton of old 42 Fountains out there with twin 500's and B1 drives so if it is set up correctly it will help it with stand the added horse power.

[weekend@burnies]

Thanks for the advice, I really appreciate it.
John I will be calling for a drive shower and some drive oil in the near future

[Ratickle]

This may be something you don't want to answer, but;


Why the Simrek vs. some of the other showers out there?

[John P]

I have see the difference in the oil life after installing this brand. I'm not taking anything away from the rest as long as they are spraying any water it has to be better than nothing. So for the ease of installing and efficiency it just my choice of shower.

[Wayne Pennell]

I'm running 650+ Hp on a 2004 B1x with no issues with about fourty hours on it. My boat empty is about 4500 lbs maybe 6000 loaded up.

[Bilgerat]

simrek's spray most water on the side and back of the case where the case is thinner and in contact with the lube inside. Those that just bounce some water off the top cap do not transfer near as much heat.

[Ratickle]

Thanks. I've got to put one on the Marlin's new shorty I guess.....

[osur866]

600 HP, 2,800lb 24* bottom 80hrs of use 2006 Bravo 1 upper Imco lower drive shower no issues thus far.

[Ratickle]

That's nice to know. How hard do you drive it????

[osur866]

That's nice to know. How hard do you drive it????

I run it pretty hard, have about 80 hrs. on the current set up, 460 total hrs on the drive, I spin it up to 6,000 rpm and it sees 5,600-5,800 often :)

[osur866]

It sees it's air time as well, one thing to consider here tho I only run 3 & 4 bladed props I think sometimes this is overlooked when people want their Bravo's to last behind bigger power.

[Ratickle]

I do know the Bravo's with 4 blades on Black Thunders have had some issues before guys like John figured out how to help them....