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John B
07-25-2017, 09:42 AM
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

Ghost
07-25-2017, 10:30 AM
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

undertaker
07-25-2017, 11:54 AM
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:shades::shades:

Carl C
07-25-2017, 08:07 PM
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.

roadtrip se
07-25-2017, 11:56 PM
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

on_plane
07-26-2017, 08:52 AM
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

John B
07-26-2017, 04:24 PM
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/

John B
07-26-2017, 04:48 PM
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

on_plane
07-26-2017, 05:13 PM
I got it and replied to PM, but if you dont get i the reply my number is 716 316 6495

Thanks
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

roadtrip se
07-26-2017, 11:45 PM
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...

Pat McPherson
07-27-2017, 03:22 PM
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:yes:

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.

John B
07-29-2017, 10:49 AM
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-propellers/sterndrive/max5/

86112

CanadianEhTeam
07-29-2017, 12:37 PM
+1:yes:

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?

Carl C
07-29-2017, 01:33 PM
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.

yeller
07-29-2017, 03:49 PM
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 :eek:). AFAIK shorties would require another couple inches.

I have to agree with Carl, that you may be your over estimating your HP.

John B
07-31-2017, 08:26 AM
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.

Could be, as the engine was not dynoed. I think my problem is prop slip though. I had a good run yesterday with the same old 28p Hydromotive 3 blade as the Bravo 4 blade hasn't arrived yet. Ran 78 GPS @ 5,400 rpm bumping the limiter again, 3 people 1/2 fuel, trimmed 1/2 out. I calculate that as 18.3% prop slip, which is a lot.

I have to admit, at that speed it's a bit of a handful and I'm starting to think about hydraulic dual ram steering. Carl, you the same XR/IMCO setup, what steering do you have?

Pat McPherson
07-31-2017, 08:59 AM
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-propellers/sterndrive/max5/

86112

My boat will run 70mph GPS at 4800rpm with full load of fuel and 4 people. 73mph at 5000 rpm with just me and light on fuel. With the Rev 4, I can trim away any porpus at any speed; with my Mirage 3 blade the handling is not nearly as good.

A stock 28p Bravo is more like 26.5" pitch. Like I said, I don't like them on old school deep V boats. I did have good success with a BBlades modified 28P on my 97 24' Superboat.

MinxRaider
07-31-2017, 03:39 PM
Hi. Saw some of these past posts and wanted to ask if anyone had issues when they put the 2" shortie on your Donzi classic. I am getting major slippage/cavitation since I put the shortie on. I have a small supercharger on a 350 SBC. Should be making around 400hp but still questioning that. I tried a Mirage 21p and a Rev 4 blade 19p and both where very bad. Boat handled real sloppy too. I do have a Rev 23p that I could try but wondering if something else is wrong. Appreciate any info you have on this..

Pat McPherson
07-31-2017, 04:05 PM
Hi. Saw some of these past posts and wanted to ask if anyone had issues when they put the 2" shortie on your Donzi classic. I am getting major slippage/cavitation since I put the shortie on. I have a small supercharger on a 350 SBC. Should be making around 400hp but still questioning that. I tried a Mirage 21p and a Rev 4 blade 19p and both where very bad. Boat handled real sloppy too. I do have a Rev 23p that I could try but wondering if something else is wrong. Appreciate any info you have on this..

How far below the bottom is the prop shaft?
Are you running an Alpha SS or did you switch to a Bravo?

On my 22' the prop is 7" below with standard Bravo. Guys run 2" shorty with great success.
I owned a 20' Minx with 350 Alpha drive but never checked how deep or if a SS would work.

I think about 5" below the round bottom is a good spot for these boats.

CHACHI
07-31-2017, 07:50 PM
I had a Minx with with an Alpha S/S....gained zero.

I don't know how much shorter a Imco -2 shortie on a Bravo upper is over the S/S, but I know the S/S didn't work for me.

Ken

MinxRaider
08-01-2017, 10:24 AM
I am running a Bravo drive with the 2" shortie (replaced the original Alpha at the same height). The standard Bravo was close to 8" below the bottom so I assume I should be around 6" now. Unfortunately didn't get a measurement before the boat went in the water. Just seems to have a real bad effect overall and not sure a prop can fix it.. Putting tabs down made things much worse..

John B
08-02-2017, 07:51 AM
I just tried the stock 28p Bravo from BBlades yesterday and immediately felt the difference. The boat came up on plane much easier and at lower rpm, now about 2,200 rpm vs about 3,000 with the 3 blade 28p Hydromotive. It handled better in turns at cruising speeds and generally felt more stable. Max speed on this run was 80 mph GPS at 5,200 rpm with three people and 1/4 fuel. I only trimmed it out 1/2 way as it felt a little different than before, maybe more torque steer and I didn't want to push it with passengers on board. The boat likes the 4 blade with the shorty and I'm getting close to where I wanted to be but that's still more prop slip than I expected, I calculate 13%. I'd like to see RPMs up to 5,400. But I'll do another test solo and trim it out more before I try to reduce pitch.

John B
08-02-2017, 07:59 AM
I am running a Bravo drive with the 2" shortie (replaced the original Alpha at the same height). The standard Bravo was close to 8" below the bottom so I assume I should be around 6" now. Unfortunately didn't get a measurement before the boat went in the water. Just seems to have a real bad effect overall and not sure a prop can fix it.. Putting tabs down made things much worse..

Minx, I didn't like the feel of the shorty on my 22C at first. It took more patience on the throttle to get it up on plane and required the use of tabs, which it didn't before. As I learned how to "Tickle" it up on plane patiently I got used to it. I just put a 4 blade prop on and it's now much better (see post above). I'm now a full shorty convert. My prop is 5" below the V at the transom with neutral trim.

Carl C
08-02-2017, 03:49 PM
Good news! Hopefully you can squeeze out a few more rpm and mph.

Pat McPherson
08-03-2017, 12:47 PM
I just tried the stock 28p Bravo from BBlades yesterday and immediately felt the difference. The boat came up on plane much easier and at lower rpm, now about 2,200 rpm vs about 3,000 with the 3 blade 28p Hydromotive. It handled better in turns at cruising speeds and generally felt more stable. Max speed on this run was 80 mph GPS at 5,200 rpm with three people and 1/4 fuel. I only trimmed it out 1/2 way as it felt a little different than before, maybe more torque steer and I didn't want to push it with passengers on board. The boat likes the 4 blade with the shorty and I'm getting close to where I wanted to be but that's still more prop slip than I expected, I calculate 13%. I'd like to see RPMs up to 5,400. But I'll do another test solo and trim it out more before I try to reduce pitch.

Good News!
Test her solo with the B1 28p and record numbers at just on plane, mid range 3400ish, and WOT. You may choose to go for a 30p if planning to lab. BBlades has a good formula to lab/modify B1 props for more bow lift and that's what these boats need.
You may also want to test a round ear Hydro 4 blade and a 5 blade prior to labbing...

My 24' Superboat ran 78mph at 5000rpm with BBlades labbed 28p B1.

Pat McPherson
08-03-2017, 12:56 PM
I am running a Bravo drive with the 2" shortie (replaced the original Alpha at the same height). The standard Bravo was close to 8" below the bottom so I assume I should be around 6" now. Unfortunately didn't get a measurement before the boat went in the water. Just seems to have a real bad effect overall and not sure a prop can fix it.. Putting tabs down made things much worse..

A Bravo drive is a little longer than an Alpha and I'm guessing that a Bravo with 2" shorty is similar to an Alpha SS in length.

I would not think 6" below is too high but you could try a 1" spacer.
I would check drive alignment and make sure your steering is tight/not sloppy.

Greg Guimond
08-03-2017, 04:23 PM
I just tried the stock 28p Bravo from BBlades yesterday and immediately felt the difference. Max speed on this run was 80 mph GPS at 5,200 rpm with three people and 1/4 fuel. I only trimmed it out 1/2 way. The boat likes the 4 blade with the shorty.

You can get a Revolution 4 "XP" in 25.5 pitch. Might be worth asking Bblades about testing one out as a comparison as they run a touch stiff.

JParanee
08-03-2017, 09:52 PM
I'm running a 4 blade 26 pitch Bravo that has been labbed by BBlades

still breaking motor in and hopefully just worked out some carb issues I'll find out this weekend hopefully

so far it seems to get up okay and at about 4300 rpm just starting to trim it up it's hitting 65 so I am anxious to see what she will turn

snave8
08-08-2017, 09:48 AM
Minx, I didn't like the feel of the shorty on my 22C at first. It took more patience on the throttle to get it up on plane and required the use of tabs, which it didn't before. As I learned how to "Tickle" it up on plane patiently I got used to it. I just put a 4 blade prop on and it's now much better (see post above). I'm now a full shorty convert. My prop is 5" below the V at the transom with neutral trim.

As has been said before.......Each 22C is different to some degree.
I installed an IMCO -2" shorty on my Bravo 1X and the boat is better in every aspect. Handles much better, mid range porpoise is reduced, gained almost 5 MPH on top end and get's on plane just as easily as with the stock lower unit. My prop shaft is now about 5 1/4" below the bottom.
Was running a Bravo 1 26P and decided to try a 28P. The boat handles better with the 28, get's on plane effortlessly, and is 2 MPH faster on top end. I've tried several 3 and 4 blade props, and the Bravo 1 is hands down the best prop on MY boat.
Stock 496 non-HO with whipple reprogram, runs 72 MPH @ 2000' msl. with 2 people and 1/2 fuel.

Pat McPherson
08-09-2017, 12:30 PM
I want one, but not for $4500. Anyone know where to buy good used or new in $2000 range?

yeller
08-09-2017, 09:31 PM
Pat, I've been looking for the last few years, just so I know what the prices are when I finally decide to go that route.
Keep an eye on the classified and swap section of OSO. They come up occasionally in the mid to high 2's but go pretty fast.
Pretty rare to find them at 2k.

I've seen guys post a "wanted" in the swap section and get a couple responses from guys that weren't currently listing.

To get a good used one, expect to pay at least 2500.

roadtrip se
08-09-2017, 10:12 PM
Wouldn't do it. If you must, look at the OSO swap shop or Wilson Marine.
Try to go XR shaft. There are a few guys in the community who are IMCO dealers too. You get what you pay for, always.

MinxRaider
08-13-2017, 08:46 AM
A Bravo drive is a little longer than an Alpha and I'm guessing that a Bravo with 2" shorty is similar to an Alpha SS in length.

I would not think 6" below is too high but you could try a 1" spacer.
I would check drive alignment and make sure your steering is tight/not sloppy.

Pat I am running standard Merc steering do you think to run the shortie drive I need external steering? Also seems like everyone is using higher pitch props so I will try my 23 Revolution.

MinxRaider
08-13-2017, 10:10 AM
Pat I am running standard Merc steering do you think to run the shortie drive I need external steering? Also seems like everyone is using higher pitch props so I will try my 23 Revolution.

One other question someone said to switch the trim-in limit insert to get the drive tucked down more. Is that going to help my issues?

Pat McPherson
08-14-2017, 12:27 PM
Pat I am running standard Merc steering do you think to run the shortie drive I need external steering? Also seems like everyone is using higher pitch props so I will try my 23 Revolution.

I've read mostly that at speeds above 65mph that external rams are desired.
In my experience, if the gimbal and stock internal power steering is all in good shape with minimal play, you're probably good to low 70s. My boat and other that I know of run low to mid 70s with stock Merc power steering and cable helm.
External steering rams and full hydraulic helm is the way to go if you run hard and above 75mph...

As for the trim limiter, I run mine so that the drive will go all the way down past neutral. This helps mainly to get on plane quickly.

John B
08-21-2017, 06:29 AM
I tried a 30p Bravo 1 yesterday. With 2 people & full fuel it ran 80 mph, the same as with the 28p but at 5,100 rpm vs 5,500 with the 28p. It was a little too rough to really go comfortably so I only did one short speed run. I probably could have trimmed it out a little more if it was smoother and I ran longer. Bottom line though, I think the 30p Bravo is the right prop. It's a handful at 80 and I'll definitely be adding dual ram external steering and reinforcing the transom over the winter.

Ghost
08-21-2017, 03:07 PM
Nice, that's progress! Thinking with a lighter load, better water and fall temps, you might see 84 before the season ends.

John B
10-23-2017, 01:52 PM
Another update and improvement. I tried a Mercury Racing Max5 5-blade 28p prop and without really trying it ran 82.5mph @ 5,300 rpm, about 12% slip. I only trimmed it out about half way. The Max5 seems to really like to be trimmed out, you can really feel the boat respond to trim, but I didn't want to push it too much until I install Latham dual ram steering over the winter. The Max5 runs more efficiently (less slip) and also handles nicely. It steps right up on plane without tabs and turns nicely. This is my best prop so far. I hope this is helpful to someone out there.

http://www.mercuryracing.com/boat-propellers/sterndrive/max5/