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Thread: 22 Classic - Prop advice

  1. #1
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    22 Classic - Prop advice

    I have a 1990 22 Classic I've been messing with for a few years. It started out with a 330 hp 454 OMC King Cobra and now has a 600 hp 540 ci with Merc XR Sportmaster and an IMCO 2" shorty. After experiencing fueling problems most of last season with the new engine / drive setup I really only got it running properly this season. With the IMCO shorty it's harder to get up on plane but I'm getting used to it. Running a Hydromotive 3 blade 28 pitch prop I see 78 mph GPS at 5,400 rpm. I'm a little disappointed as I was expecting 80+. I think it is bumping the soft limiter at 5,400 so am looking to increase pitch. After looking at all the prop options my head is spinning. I'm looking for advice from anyone with experience with an IMCO shorty 80 mph+ boat. I don't mind a little chine walk and don't want to sacrifice much speed for handling. I may try a 4 blade or even a 5 blade just to see though, maybe trimmed up high they may give good speed? Here's a subset of what I see as options. Once I have the right prop I'll have it labbed. Wisdom from the group is much appreciated.

    3 blade:
    Hydromotive Intimidator III 29 pitch 15.5 diameter
    Mercury Mirage+ 29 pitch 15 diameter
    Turbo TXP 29 pitch 14.75 diameter

    4 blade:
    Hydromotive Intimidator Quad 4 29 pitch 15.5 diameter
    Mercury Pro Max 29 pitch 14.75 diameter

    5 blade:
    Mercury Racing Max5 29 pitch 15 diameter
    Mercury Maximus 30 pitch 15.25 diameter
    Hydromotive Intimidator P5 29 pitch 15.5 diameter

  2. #2
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    Handful of guys here run 22s with XR drives and Imco 2" shorties. Pretty proven setup and I expect you'll get lots of good help. I agree that I'd expect you to get over 80, though if it's all only been tested in the hottest and most humid part of the summer, perhaps not. In anticipation of more dialogue with those guys, couple questions come to mind.

    Did you you actually get dyno testing that showed 600hp or was it just built with that as a goal?

    I presume you have 1.5 gears? I ran your numbers and it sounds like you're slipping a LOT. More than I'd think you want. Here's that result if it helps with the prop planning: 18% slip at 5400, 1.5 gears, 28" pitch and 78mph

    Regards,

    Mike
    "I don't have time to get into it, but he went through a lot." -Pulp Fiction

  3. #3
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    In your four blade catagory you should try a labbed 30P bravo prop, you might even be able to turn a labbed 32P bravo if 600 HP is a solid number. I am totally stock on my 22 (496 HO) and run a bravo/shorty setup 1.50 gears and turn a labbed 28P bravo 5100 @ 75mph. I know a few guys who run kind of stock Merc 502 & 500, 525 EFI (blue motors) with the same drive combo and they are running labbed 30P bravo. Bravos seem to work real well handling & top end wise IMO.

    The three blades will be a bit harder out of the hole with the shorty compared to the four blades (I have no issues getting out of hole with my setup). Might be a little faster, but from what I have heard and seen over the years do not handle like the four blades (bravos)

    Undertaker

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    I second the 30p Bravo 1. They are over-rated in pitch. I'm running a stock 525, bravo XR, Imco -2", 30p bblades labbed Bravo 1. Low to mid 80s. Bumping rev limiter in perfect conditions.
    Lake St. Clair, Lake Huron, Lake Erie, Lake Oakland

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    John, I have been running this set-up in various forms for a long time.
    I have taken the liberty of revising your target list, based on my testing.
    You should be shooting for 9-10 percent slip. And forget about top end calculations on most slip calculators. Hope it helps and good luck with your testing. They all run different...

    3 blade:
    Mercury Mirage+ 29 pitch 15 diameter
    Turbo TXP 28 pitch 14.75 diameter

    4 blade:
    Hydromotive Intimidator Quad 4 27 pitch 15.5 diameter
    Bravo One 26 pitch 14.75 diameter

    5 blade:
    Hydromotive Intimidator P5X 26 pitch 15.0 diameter
    Hydromotive Intimidator P5 26 pitch 15.5 diameter
    Hering Bravo 5 Blade 25 pitch, 20 degree rake, 15.0 diameter

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    Ive got a bravo 30P rh I would like to sell, if interested. 450.00 + shipping in original box. Basically new. Used 3 or 4 times on my 22, too much prop for my application.

    PM me if you want to discuss

    Paul

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    Thanks for the help guys.
    I calculate the 18% slip number as well, that's too much.
    Brad from BBlades finally got back to me and he also recommended a 4 blade Bravo. He said with that high slip number a 4 blade will probably add speed as the slip improves. He steered me to a 28p to start and that's on its way. If there is still too much slip with that he recommended a 1" spacer in the drive to lower the prop. Right now with the 2" IMCO shorty the prop center (nose cone point) is 5" below the bottom of the V at the transom in neutral trim. Is that too high? The XR Sportsman was mounted using the holes left by the prior OMC King Cobra. The engine was built by Corretti racing. It wasn't dynoed itself but was built to the same spec as many he has done that dynoed 625. He does a lot of these. I'll report back after trying the Bravo.


    http://www.correttiracingengines.com/
    Attached Images Attached Images

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    Quote Originally Posted by on_plane View Post
    Ive got a bravo 30P rh I would like to sell, if interested. 450.00 + shipping in original box. Basically new. Used 3 or 4 times on my 22, too much prop for my application.

    PM me if you want to discuss

    Paul
    Hi Paul, Thanks, I'll take that. I tried to PM you but it does not seem to work, I see nothing sent.

    John
    c 732 618 0766 jburke79x@gmail.com

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    I got it and replied to PM, but if you dont get i the reply my number is 716 316 6495

    Thanks
    Paul

    Quote Originally Posted by John B View Post
    Hi Paul, Thanks, I'll take that. I tried to PM you but it does not seem to work, I see nothing sent.

    John
    c 732 618 0766 jburke79x@gmail.com

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    John, a couple of scattered thoughts..

    I was able to run 80 on demand with a 500EFI and shortie. The 500 was rated at 470 HP.

    My prop recommendations were based on what you are achieving now with the Hydro 3 blade. Reality? With a 9-10% slip number and 625 HP, you should be breaking 83-85.

    Your prop depth is close to mine. Spacing down a shortie defeats the reason for having one. There are a ton of guys running IMCO shorties here, without adjusting the stock depth.

    I like Brett Anderson's testing program, but his whole commercial program seems to be based on selling labbing services to make Bravo Ones work. My preference is to find a prop that runs without a lot of customization work. It's also easier to fix or replace a prop that hasn't been highly customized. I run a Hydro P5X in stock form and it works great. Been there done that with lab work in the past.

    Food for thought...

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    Quote Originally Posted by roadtrip se View Post
    I like Brett Anderson's testing program, but his whole commercial program seems to be based on selling labbing services to make Bravo Ones work. My preference is to find a prop that runs without a lot of customization work. It's also easier to fix or replace a prop that hasn't been highly customized. I run a Hydro P5X in stock form and it works great. Been there done that with lab work in the past.
    Food for thought...
    +1

    I don't like the Bravo 1 prop in it's stock form on these old school V bottom boats. Not enough bow lift without modification.

    The best stock 4 blade is the Merc Rev 4 but unfortunately they only come with max of 25p. After testing many props, I run the a 25p Rev 4. My boat is powered by stock 502mag and stock B1 drive set deep, like 7" below.

    I loved running the P5X on my two 24X7 boats. I've not tried on my 22' Donzi but I'm sure it would run great.

    In your shoes, I'd try a P5X 27 or 28p. They cost like $900 but that's about the same as a BBlades Labbed Bravo 1.

    Don't add a spacer, 5" below is plenty.Both of my 24X7 boats were set 5" below from the factory. Many many guys running the shorty and Donzi built a few years/models with the prop at 5" below.
    Thank you, Patrick
    1994 18' Classic 350Mag Alpha

    Previously owned Donzis -
    1996 22' Classic, 502Mag Bravo
    1987 20' Minx, 350Mag Alpha
    1975 18' Classic, 350Chevy Volvo 280

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    I'm still waiting for the 28p Bravo 1 to arrive to test.
    In the meantime roadtrips numbers are starting to make sense to me. With 9-10% slip 28p could be too much. I made a handy HP, Speed, Pitch calculator in excel, seems I'd need about 750 hp to turn that wheel properly at 5,400 then I'd be going 87 mph. I would link it here, but the forum doesn't accept excel files. If anyone would like it PM me your email

    Pat - good input. I wonder how the new Mercury racing Max5 would work?
    http://mercuryracing.com/boat-propel...erndrive/max5/

    Donzi calc.png

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    Quote Originally Posted by Pat McPherson View Post
    +1

    I don't like the Bravo 1 prop in it's stock form on these old school V bottom boats. Not enough bow lift without modification.

    The best stock 4 blade is the Merc Rev 4 but unfortunately they only come with max of 25p. After testing many props, I run the a 25p Rev 4. My boat is powered by stock 502mag and stock B1 drive set deep, like 7" below.

    I loved running the P5X on my two 24X7 boats. I've not tried on my 22' Donzi but I'm sure it would run great.

    In your shoes, I'd try a P5X 27 or 28p. They cost like $900 but that's about the same as a BBlades Labbed Bravo 1.

    Don't add a spacer, 5" below is plenty.Both of my 24X7 boats were set 5" below from the factory. Many many guys running the shorty and Donzi built a few years/models with the prop at 5" below.

    Tried to pm you Pat but you box is full. What type of speeds are you seeing with the Merc rev4 and your stock 502? Does it still have the midrange porpoise?

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    Quote Originally Posted by John B View Post
    I'm still waiting for the 28p Bravo 1 to arrive to test.
    In the meantime roadtrips numbers are starting to make sense to me. With 9-10% slip 28p could be too much. I made a handy HP, Speed, Pitch calculator in excel, seems I'd need about 750 hp to turn that wheel properly at 5,400 then I'd be going 87 mph.
    All props are not equal in pitch rating. The Bravo 1 is over-rated by at least one pitch number. I spin a BBlades labbed 30p Bravo 1 behind a stock 525, also with Bravo XR/Imco -2" lower. The 525 usually dynos around 540 hp. I bump the rev limiter at 5,400 rpm in ideal conditions. It sounds like your hp numbers are a little optimistic.
    Lake St. Clair, Lake Huron, Lake Erie, Lake Oakland

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    If you have an honest 600hp, then 80mph would be no problem. At that HP, I'd think a 28" on a shorty would be way under propped.

    With my 496HO/Procharger, I had probably 550hp, give or take. With the stock Bravo, I ran a 28" Mirage +, 28" Tempest +, 27" Hydromotive Q4. All would run close to or brush the rev limiter (the odd time I could get it up there ). AFAIK shorties would require another couple inches.

    I have to agree with Carl, that you may be your over estimating your HP.
    Why is faster never fast enough.

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