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Conquistador_del_mar
10-06-2013, 02:45 PM
Has anyone solved an extreme leaning problem by changing prop rotation on a Bravo or Volvo drive deep V hull? I know that it is recommended to turn the same direction prop as the driver seat, but has anyone had better results on the leaning problem by switching to the opposite direction rotation prop? I read somewhere that hull and drive combinations sometimes work out better in the opposite direction. Has anyone experienced this?

mphatc
10-06-2013, 06:56 PM
Bill,

I had an extreme leaning problem with the Corsican, finally solved it with a new prop from BBlades . . numerous props exhibted the same issues, and this was not why I went to BBlades.

The Corsican was left steering with a Bravo turning left, I never tried a RH prop.

Mario L.

Carl C
10-06-2013, 08:03 PM
Here is my take on this. To correct the listing at slow to moderate speeds you drag a little port tab. As speed increases and you raise the drive, the positive trim angle of the prop cancels out the torque steer and you can raise the tab completely as you raise the drive. Now with reversing the prop direction would the opposite not be true? That is, you might run flatter at lower speeds without tab but as you trimmed the drive up the prop torque effect would induce listing and you would need to drag some tab. This does not sound like a good thing to do since you need the tabs out of the water for top end. The only boat that I know of that has done it is the Ilmor 22 (not Ted's) that keeps popping up for sale because of handling problems. I would personally never consider doing that.

Conquistador_del_mar
10-07-2013, 12:30 AM
Bill,

I had an extreme leaning problem with the Corsican, finally solved it with a new prop from BBlades . . numerous props exhibted the same issues, and this was not why I went to BBlades.

The Corsican was left steering with a Bravo turning left, I never tried a RH prop.

Mario L.

What type prop lessened the lean? Have you also read where some boat/drive combinations do better with changing the prop rotation?


Here is my take on this. To correct the listing at slow to moderate speeds you drag a little port tab. As speed increases and you raise the drive, the positive trim angle of the prop cancels out the torque steer and you can raise the tab completely as you raise the drive. Now with reversing the prop direction would the opposite not be true? That is, you might run flatter at lower speeds without tab but as you trimmed the drive up the prop torque effect would induce listing and you would need to drag some tab. This does not sound like a good thing to do since you need the tabs out of the water for top end. The only boat that I know of that has done it is the Ilmor 22 (not Ted's) that keeps popping up for sale because of handling problems. I would personally never consider doing that.

I used to think that changing rotation would simply make the boat lean the same in the other direction, but I have read that this is not always true due to inconsistencies in hull and drive factors. I am asking if anyone has experienced this to be true.

Pat McPherson
10-07-2013, 08:46 AM
My buds 29" Fountain runs a left with steering on the right. My last boat, a 280 Velocity came to me spinning a lefty but I switched it to a righty because RH props are easier to come by. I doesn't hurt to try running a lefty, and on a Bravo it's an easy swap. Every boat is a little different, some handle better, some not. On a narrow boat like our Donzi Classics, I would run the rotation that counteracts the weight of the driver. Some high power boats are setup to counter act the torque of the engine rotation. One thing to consider is that a lefty spinning Bravo loads the top cap and the drive may not last as long as if spinning righty.

Conquistador_del_mar
10-07-2013, 07:31 PM
My buds 29" Fountain runs a left with steering on the right. My last boat, a 280 Velocity came to me spinning a lefty but I switched it to a righty because RH props are easier to come by. I doesn't hurt to try running a lefty, and on a Bravo it's an easy swap. Every boat is a little different, some handle better, some not. On a narrow boat like our Donzi Classics, I would run the rotation that counteracts the weight of the driver. Some high power boats are setup to counter act the torque of the engine rotation. One thing to consider is that a lefty spinning Bravo loads the top cap and the drive may not last as long as if spinning righty.


Thanks Pat,
I think the IMCO Extreme drive I am running has a stronger top cap that might hold up if I end up going left from now on. I will report the results as soon as I try the left prop. Bill

Greg Guimond
10-08-2013, 11:36 AM
This will be an interesting test to watch with the LH prop approach for sure.

joseph m. hahnl
10-08-2013, 05:35 PM
:confused: I thought a left hand prop was made for a counter rotating engine. To run a left You have to reverse the cable and run the gear set in reverse:frown:. The Minx lists only when it comes off plane , and a hard steer in to it, keeps it some what level:tooth:. I think pitch and torque would be the prime suspect , and I reckon a prop with more slip would help:biggrin.: Or Use more trim to slip the Prop.:kingme:


What is the prop you using?

Conquistador_del_mar
10-08-2013, 09:05 PM
:confused: I thought a left hand prop was made for a counter rotating engine. To run a left You have to reverse the cable and run the gear set in reverse:frown:. The Minx lists only when it comes off plane , and a hard steer in to it, keeps it some what level:tooth:. I think pitch and torque would be the prime suspect , and I reckon a prop with more slip would help:biggrin.: Or Use more trim to slip the Prop.:kingme:


What is the prop you using?

You can turn either direction props with older Volvo Pentas or Bravo drives by simply changing the shift connections since they are both cone clutch design drives. In my case, I have tried RH Bravo 1 4 blade prop and a Fusion 4 prop with both making the boat lean heavily to the left. My drive is a IMCO Extreme with the same lower foot as the shortie, but mine is regular length. This is on my 28' Warlock deep v hull.
I was hoping to hear if anyone had solved a leaning situation by simply changing prop direction.

mphatc
10-08-2013, 10:09 PM
What type prop lessened the lean? Have you also read where some boat/drive combinations do better with changing the prop rotation?




I used to think that changing rotation would simply make the boat lean the same in the other direction, but I have read that this is not always true due to inconsistencies in hull and drive factors. I am asking if anyone has experienced this to be true.


I ended up with a Hydromotive Quad IV that I had BBlades trim down the OD on and reduce the pitch as best I can recall. As I think about it I also found that the boat was hugely different in salt water!!! So much that I didn't enjoy the freshwater boating after a weekend of salt! And that wasn't the Marguritas effecting me:)

I ran various props all LH, including a few out board props . .The worst prop was a Mirage , one of the quicker ones was a $50.00 chopper I found on Craigslist!

Hull and drive factors . . you must have an absolutely tight gimble , you don't want prop torque to twist or angle the drive.

Greg Guimond
10-08-2013, 10:57 PM
The specific tolerance of the drive angle is a key piece of data.

joseph m. hahnl
10-09-2013, 05:02 PM
I ended up with a Hydromotive Quad IV that I had BBlades trim down the OD on and reduce the pitch as best I can recall. As I think about it I also found that the boat was hugely different in salt water!!! So much that I didn't enjoy the freshwater boating after a weekend of salt! And that wasn't the Marguritas effecting me:)

I ran various props all LH, including a few out board props . .The worst prop was a Mirage , one of the quicker ones was a $50.00 chopper I found on Craigslist!

Hull and drive factors . . you must have an absolutely tight gimble , you don't want prop torque to twist or angle the drive. You'd think the 3 blade Mirage would have less list than a 4 blade.:lookaroun: What pitch:confused: The 21p on the Minx is a little small now. It slips like crazy:biggrin.: A new prop is in my near future :kingme:

Pat McPherson
10-09-2013, 07:50 PM
You'd think the 3 blade Mirage would have less list than a 4 blade.:lookaroun: What pitch:confused: The 21p on the Minx is a little small now. It slips like crazy:biggrin.: A new prop is in my near future :kingme:

I've got a 25p if you like to try it...I ran a 23p mirage on my Minx with 300HP.

One prop that might work well on the Warlock is a Hydro P5X. It worked great on my 24' Super; I just didn't want to spend the $900...

Conquistador_del_mar
10-10-2013, 12:59 PM
Mario,
I find it interesting that the Hydromotive ended up being the best prop (with mods) on your Corsican and that the Mirage was the worst prop.

Pat,
I am going to take out a few friends on Sunday and I am torn between trying the new RH 5 blade Cutting Edge 27P that I bought a year ago or a LH Hydromotive Q IV 27P. This afternoon we will finish the steering system repair of the swivel pin/steering arm replacement so I might take it out for a trial using one of them before Sunday. If it didn't work, I can try the other on Sunday. Did you have a 24' Superboat that the Hydromotive P5X worked so well on? No negative aspects running the 5 blade prop?

I should mention that the gimbal ring has always been tight so any problem with leaning was not related to the outdrive twisting or leaning - the steering problem we are fixing was the loose upper steering arm which is also unrelated to the boat leaning since it is not a factor in drive angle, etc.

Pat McPherson
10-10-2013, 08:38 PM
Back in the days I had my 24X7, I ran with a fellow with a 600HP 24' Pantera and another with a 500HP 24' Condor. We swapped props around and tested a number of Hydro and Merc props from BBlades. The Condor was set up with the prop shaft about 4" below the bottom and both my Superboat and the Pantera had the prop shaft about 5" below.

We found the best props in their stock form were the Merc Rev 4 and the Hydro P5X; low slip, great overall lift, and vary stable.
The Merc M+ worked OK on my Super; the other guys didn't like them. The M+ was the fastest on my boat and a labbed 27p pushed my stock 502Mag powered 24 Super to 78mph.
The Merc B1 was OK but not great in stock form. BBlades altered one for me to add bow lift and it worked well.
No real luck with Hydro props other than the P5X.

I ran the modified 28p B1 but would have bought a Rev 4 if one come in 27p or a P5X if I hadn't gotten sticker shock.
The other guys ran 25 or 26p Hydro P5Xs; they seemed to be just as fast as any of the 4 blade props. The Pantera would run 80+ and the Condor topped out at about 75.

I also tested props with a fellow with a 525EFI powered 30' Superboat. The P5X and BBlades modified B1 were the best props for the boat as well. Why not a 28' Warlock...;)

I'd bet a P5X would be a great prop on a 22' Classic with a shorty.

Conquistador_del_mar
10-11-2013, 02:17 AM
Thank you Pat for taking the time to make such a detailed post about your prop trials. I will use all this information and report what I find thru testing on the Warlock. Bill

Greg Guimond
10-11-2013, 10:56 AM
Both the Superboat 24 and the Team Warlock 28 are 24 degree deadrise straight V's I believe and both narrow beam. Pat, did you 24 have even a small pad on the bottom? My 21's did but when I drove an older 24 Superboat I seem to remember that is was a straight V to the transom with no pad.

Pat McPherson
10-11-2013, 11:16 AM
Both the Superboat 24 and the Team Warlock 28 are 24 degree deadrise straight V's I believe and both narrow beam. Pat, did you 24 have even a small pad on the bottom? My 21's did but when I drove an older 24 Superboat I seem to remember that is was a straight V to the transom with no pad.

The newer 24' Supers have a small step and larger strakes but no pad. I recall the Pantera bottom had the V clipped off for maybe the last 8" but I woun't call it a pad.

Conquistador_del_mar
10-11-2013, 12:43 PM
The newer 24' Supers have a small step and larger strakes but no pad. I recall the Pantera bottom had the V clipped off for maybe the last 8" but I woun't call it a pad.

Wouldn't that bottom on the Pantera be called a notched transom with the concept that the drive and prop get cleaner water?

Pat McPherson
10-11-2013, 02:19 PM
Wouldn't that bottom on the Pantera be called a notched transom with the concept that the drive and prop get cleaner water?
No the transome on the 24' Pantera was not notched; the V on the bottom was simply flattend for the last 6-8 inches. Some 28' Panteras do have a notch; which is much like removing the last 8 inches of bottom/running surface to give "clean water" to the prop.

Greg Guimond
10-11-2013, 03:09 PM
The 1997 24' Supers have a V al the way

Thanks. The Team Warlock 28 and your old 1997 Superboat 24 could present Bill with an interesting science experiment for propping. They both are 24 degree straight V's, both are narrow beams, although I believe the Superboat 24's to be a little narrower, and neither have a delta pad bottom. The Left Hand prop experiment will be telling.

Greg Guimond
10-11-2013, 08:49 PM
Some comments on a hull that leaned ........


After our first take-off andhuge lean, Andy handed the helm over to me to see if it was driver error. I attempted to use the tabs to correct thelow speed lean, but what you end up with is a very sensitive, over active taband a boat that reacts big time to small tab movements. The boat leans to thestarboard side on take-off, so even with a small amount of down tab on thestarboard side it will throw it over to lean to port pretty hard. Not having any real feedback, I felt we hadto make some big changes. This boat was originally equipped with Bennett tabsand when they mounted the Dana tabs, they just siliconed over the old Bennettholes. I spoke with Andy and he agreedto let me move the tabs in a more traditional spot. We proceeded to move thetabs to run parallel to the keel compared to running parallel to the waterline. Due to how sensitive the boat has been to the trim tabs in the past, Ifigured I would start with my loaner 12 X 17 bottom plates. At this time I alsothrew a left hand rotation prop on the boat. Because of the type of shifter theboat is equipped with, it is easy to simply drive the boat in reverse for thetime being to see if it helps.

Went to the lake. Took off, the boat lean was 95 percentgone. Not knowing what fixed the leaning problem, it could have been thereverse pitch prop or the new tab placement. I immediately went back to thetrailer, ripped the tabs off on the launch ramp and went back in the water.Took off, no lean. So great, problem 1 is fixed. The boat takes off like anormal boat now. I decided to run it out with the left hand prop on it to seeif that would help the upper end problem with no tabs. The boat is still reallysquirrely on the top end. So no luck there. Back to the ramp, put the tabs backon, back in the water. Boat takes off great, I could notice that the boat wasmuch more sensitive with turning even with the tabs all the way up. I proceededto run it up and at about 78 I got another dose of very dangerous chinewalking.

We simply could not win on the top end. The boat is sostable from take-off to 65 mph, I just could not believe it could get sosideways within 5 MPH. At that point, wewere out of options. I put the tabs back where they originally were, installedthe longer bottom plates, and went back to the lake. With the bottom endleaning problem fixed, and the upper end as stable as we could get it, we drivethe boat where it likes to be driven.

Conquistador_del_mar
10-12-2013, 12:25 AM
Greg, thank you for passing along that info.
Since Mario had some good results correcting his Corsican lean with a Hydromotive Q IV, I called a friend today who is going to loan me a RH Hydro Q IV 27P to run on Sunday if the weather holds. After hearing Pat's take on running a Bravo LH possibly pushing the top cap bearing too much, I thought I would try the RH Hydro before trying a LH Hydro.

Greg Guimond
10-12-2013, 08:38 AM
Might as well get all the props on board and your wet suit and spend tomorrow "wet swappin" each of 'em for the tests! Nothing like back to back results.