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Thread: 850hp-900hp

  1. #21
    502procharger
    craig,
    sounds like we have the same motor. i would love to here about what you did to your bravo to beef it up. my boat is a 25' switzer. it is not that heavy of a boat either, i do not know exactly what it weighs, but it is not a tank. what kind of sppeds are you seeing with that hp in your boat? i see like 82 with my 600hp, and i have no idea what to expect with 850-900hp. any info is great.
    brian

  2. #22
    Craig
    As for the Bravo, I used Billet Marine's upper gears. They take stock Merc ones, weld the floor, debur them, polish them, perform several ritualistic chants and a few other things I had them put a steel tower in as well as their vertical shaft and prop shaft. I don't use the drive water pick-up to feed the motor, so I tapped the side of the drive case and plumbed a line from there to the Billet Marine top cap. I change drive oil about every 20 hours. No hole shots and try not to get the prop out of the water in the rough stuff eek!
    I'm running 1.36 gears. Speed, 30 pitch Bravo I've seen 106.3 @ 6000 rpm. With a stock 32 Bravo, 114.5 @ 5800. This was December @ Havasu. Here in Phoenix in July and 105 degrees and humid I hit 108.4 with the 32. I'd like to try a labbed 32 or a 34 next December at the Parade of Lights and see if I can get a little more mph.
    Craig
    [ August 29, 2002, 12:32 PM: Message edited by: Craig ]

  3. #23
    chaparral2350sx
    Gnarley is right they do help in the Hp deparment.The only thing to watch out for when running a dry sump oil system is cold oil. The high flow rates of the oil can posibly break the pump or cause internal damage. make sure the oil is good and warm before you really nail it. But they are the best way to oil a engine if you are going to turn lots of Hp and Rpm.
    Tom
    ...2 1/2 cents worth

  4. #24
    Dave F
    I didn't read everyones reply so if I'm saying something that's already been said I apologize.
    First, let me disspell some of the myths that I've been reading on the first 10 posts or so.
    Let me also say I'm not trying to step on anyone's toes here but there are some things that guys like us need to know.
    Myth #1:
    You, by no means, need a dry sump to push 900hp.
    2. With a Pro Charger (in this case)you do not NEED anything more than what the crate GM motor comes with to push the same hp.
    3. You will not NECESSARILY break a Bravo 1 with same hp.
    I know this because I've done it.
    Crate 502 stock bottom end, 8 qt pan.
    Crane Hydraulic roller valve train
    Merlin heads
    Single plane SINGLE 800 CARB Yes, I said single carb.
    Stage 4 Pro Charger 11# in the box, 9# in the manifold = ~900hp
    CMI exhaust
    All on a 4600 lb boat with a hook on the bottom and still did around 95 mph on a totally stock bravo 1.
    Oh! one more thing I did it on 94 octane and full timing too.
    NEVER A PROBLEM.
    Breaking your Bravo has alot to do with the amount of weight it has to push and how you treat it. IN MOST CASES.
    Alot of times guys break bravos due to the way they come out of the hole and another not as well known fact, when you jump waves and come out of the water and re-enter. Lots of stress there.
    PS the boat was an 87 242ls Formula.
    If you want to set up a PC feel free to email and I'll be glad to help you out.
    DAVE

  5. #25
    Dave F
    Oh ya. One more thing. Some time ago PC had an article in Hot Boat where they put 10# in a pair of 502's using a stage 4 kit. Dyno'd at over 1000 hp. Stock bottom ends.

  6. #26
    502procharger
    dave i am already runnung a procharger at about 600hp on a 502 with like 6 lbs of boost. it has been great. i am building a sec. 540 as we speak that is bullet proof. it is about 650 hp withiout the procharger so i figure 850 to 900hp with 7 0r 8lbs. i have a stock bravo 1 now and have never had a problem. i have the chance to pick up a imco for 4k or an xr used but in good shape for 4250. my boat is less than 4k so with one of these drives i should be fine. i was thinking of just keeping the bravo 1 until i bust it, but then it will be worth next to nothing. at least now i should be able to get a few grand out of it. let me know what you think.
    also i have my timming backed down to 30 deg and run 93. i have never had any sign of detonation. should i bump it up a bit?

  7. #27
    Dave F
    There is a place in Fla. (and I cant remember the name of it) that when, or IF, you break your Bravo you can send it and get a performace build up for under $2000. When I talked to them (last year) they said all parts would be like the Imco or other upgraded drives. I'll look back in my notes to see what their name is.
    It would be a good idea to buy a spare drive. That way if you do break you can be boating again in an hour. Send the broken one to get fixed and keep on boating.
    Now, why not just buy a B-max that wont break? Well they cost over $11,000. You could buy two drives, fix them both twice for that much.
    As long as you're not going through them every season then it'll pay for itself.
    BUT THAT'S THE GAMBLE.
    You can expect 900hp from a 540 with 8# pretty much no problem.
    As far as timing. What is the exact setup, Top to bottom and I'll see if I can recommend any timing changes for you. The smallest things matter.
    DAVE

  8. #28
    502procharger
    motor i am using now is pretty much stock except for cranr cam. fast glass elbows, nickerson carb. runs like a beast though.
    new motor
    540, scat billet crank, manely pro series rods, crane roller valve train, je pistons, 9 to 1. ported rec port gm heads, dart alum. intake,msd marine dist and box, cmi headers, manely severe duty valves, imco pullies and valve covers, shinny new blue paint. areomotive electric fuel pump with boost compensating regulator. thats about all i can remember. i do need advise on where the set the total timming though.

  9. #29
    Dave F
    I was actually more interested in the smaller details:
    Jet sizes
    T-stat
    spark plug
    cam specs
    Which PC (stage 3 or 4)
    and the static comp ratio, which you've already told me is 9:1.
    They are flat top JE's right?
    Octane available/willing/able to run consistantly
    some of these questions you may have answered but these are the specifics that matter.
    DAVE

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