Best prop for an Alpha SS... ???

[Lenny]

Folks, I have a labbed cleaver, a modified MERC part, and a new TXP. The TXP moves a ton of water, (23R) and provides for a high speed cruise but at the cost of 600 rpms at the top. (4400) The Cleaver spins out to 5000 and hooks up well but NEITHER one provides the type of BOW lift I would like. (21 I believe) I play in sometimes large following seas and I like this ability in a prop so that I can "hop" to the back of the next or at least have a power influenced "bow up" attitude available from the throttle.

These props are on the ALPHA SS.

Does anyone have a recommendation of something I can spin that does provide good bite, handling AND bow rise (with trim) ?

Stock 350, (Stainless Marine, Edelbrock Performer, Barry Grant 650)

[BigGrizzly]

Lenny, you are going to encounter several situations. 1) the SS does not trim as well as the deeper drive. 2) there is always a trade off. 3) Your boat didn't like the Lightning which has more bow lift. The only option that see would be a 4 blade to help with the trim Maybe a bigger diameter. There is another option, Try a Turbo I. If that didn't work there is the Solas Scorpion or Lexor, with the biggest diameter that will fit. For me I would use a deeper drive. The real problem is no one has experimented your situation so Data is very limited. In no way will that Merc SS fly like the old Volvo s. I have gotten this complaint more then once. Lenny knows what I mean. Unless you have spent a lot of time in both style boats you can't even compare it.

[mrfixxall]

lenny see if you can get a hold of a mirage +21x15 :)

[Lenny]

Grizz, I am also bolting on the Stern Jack so I might be able to modify the "angle of the dangle" a bit with the large setback.

[BigGrizzly]

It might work, Let us know. Now you are really on uncharted water with a stern jack and a SS.

[Trueser]

Lenny,
Gus ran one of my 26 Mirage plus on his 18 with an Alpha SS. He did 75 MPH on GPS, his best speed ever.

Needless to say he wants to buy it off of me.

I still need to test the pair on my 28.

Send Gus a message and he will give you the specifics.

[Rootsy]

I liked the Hydromotive Quad IV O/T on the 16... Doug Lovins runs the same prop on his 18 / SS and he'll also run a regular ole Mirage from time to time...

[Lenny]

I liked the Hydromotive Quad IV O/T on the 16... Doug Lovins runs the same prop on his 18 / SS and he'll also run a regular ole Mirage from time to time...

Isn't the OT an outboard prop and the Quad IV the I/O prop?

[HallJ]

Lenny,

What trim tabs are you running?

Jeff

[Lenny]

Standard Bennetts, 8 1/2" length (bow to stern) x 12"s port to starboard.

[Rootsy]

Isn't the OT an outboard prop and the Quad IV the I/O prop?

yeah.... it has more rake and cup than the full sized quad IV. Gives a bit more lift. It's also 14 3/4 diameter. the exhaust hub is smaller in diameter than your gearcase bullet but that isn't an issue. Hydromotive stakes a black off ring on the exhaust hub so that you don't get air / exhaust over the hub. Fits a standard 1" propshaft.

I have a new 23" sitting on the shelf I am not going to be able to use... I've run it once or twice and that's it...

[HallJ]

Lenny,

Have you modified them to retract more?
This may help your quest for more bow rise.

http://www.donzi.net/forums/showthread.php?t=33672&highlight=trim+tabs

It works.

Jeff

[MOP]

Lenny I am with Rootsy, a 4 blade will hold the bow higher, I noticed quite a bit of difference on the 22. My boat is 1/2 MPH faster and handles better with the 4 blade then with any of the 3 blades I tested.

Phil

[Rootsy]

Phil,

I like the 4 blade O/T for the stability as well as performance it gives in this application. A Quad IV, Quad IV O/T, Bravo I, etc, while all being 4 blades will all have different geometry and therefore give different performance results.

[BigGrizzly]

Like I said this is a try thing. What people are missing is what you want. Living by and doing 80% of my driving on the ocean I can trlate to the following sea deal. Try one if you can find one. MOP get your butt up to Lake George And I will bring something just for you to try.

[BUIZILLA]

Have you modified them to retract more?
This may help your quest for more bow rise. of course.. :wink:

and yes I ran every prop known to man already.... M and the M+ is a chine walker of sorts, labbed M+ was a stern lifter.... labbed cleaver was fastest, TXP was an overall dream...

[Lenny]

of course.. :wink:



Tabs are NOT an issue here. They are up where they should be on the transom. About 1/2" up on the glasswork, and a lot more in the angle when fully retracted. They are NOT in the water.

Rootsy, what is the 23R? An OT?

I'm interested in giving that a shot.

I think the stern jack is going to yield some pleasent surprises.

[DONZI]

My experience with just bolting on the Alpha SS on my 22C and props.
23 Cleaver= some cavatation,lil trouble getting on plane at times.
24 Labbed Cleaver=lil faster,some cavatation while trying to maintain slow cruise speed & torque over when letting off from full speed.
23 Turbo 3 blade=better planing & handling ,still some cavatation at slow cruise speed.
24 Turbo 4 Blade=Overall the best. (pic. below).I actually could'a used a smaller pitch for RPM'S sake. But it gave me great mileage.:)

Installed Stern Jack w/ SS drive. This gave me the best of both worlds.No more cavatation.
High drive height with full range of Trim. The fastest set- up i've had on the boat so far.
Since then as ya know, it's back to those un-charted waters that i love so dearly.:smash::)
Be careful with those lil part's when installing the S.Jack. Fragile and may not be available for replacement.

Keep in mind the 22 also being heavier than the 18. So apples to oranges maybe.
Like Grizz said, trial & error !

SS, Safely in storage for the man in Miami.

[osur866]

Lenny, I know the Alpha SS is 1" shorter and hydromaitclly different than an Imco -2" drive but what I have found is simialer to your results most of the props don't carry the bow or the bow simply doesnt carry as well with the shorter drive, I too reduced the stern weight by 83 lbs by adding Stainless Marine exhaust which also made the boat run flatter, I've found for wfo runs I only need about 1/4 trim and the boat will run faster when the nose is not way up, I think because the stern is sucking down so much, but when running in rough water I'm able to give more trim and carry the bow at the cost of top end speed. I to liked the txp for over all but for top end I have a labbed mirage plus on which really does a good job of carrying the bow without uncontrolled chine walk, I feel this is due to the diam. of the 29p when I ran a 25p m+, with a smaller Dia. it was night and day different, I really think it is the attack angle when adding or running a shorthend drive on the 18 hull. Steve

[Rootsy]

I'll agree that the 2 cleavers I ran on my 16 / SS combo were up there in speed, not far off from the 4 blades... But the mid range cruise speeds sucked donkey balls...

[BigGrizzly]

Steve that labbed Mirage+ as you stated is way different then the M+ you did on the stock drive. Another thing is pitch, this also has a major affect on attitude of the boat. for instance if you had a 25 pitch on a boat and geared it to accommodate a 30 of the same style the boat would handle different especially to bow lift and stern lift/squat. I have not measured the prop shaft hight difference between the SS and the Imco 2 inch shorty, but I am surprised that is 1 full inch shorter then the Imco. If this is true wow. The other part is Lenny wants the boat to run with bow high for ocean only. The boat he has is great in the rough I have seen it in the nasty. What he wants is roller flying in a following sea. This is quite different. He wants a roller coaster ride. As for Rootsy and his boat. for him the4 quadIV was good. He never got to try the TXP or Fusion because his boat broke the prototype TXP showed up at Cumberland. I will guarantee that he will try them on his new project- I will see to it.:wink:

[BUIZILLA]

the SS is 2 3/4" shorter than a stock Alpha...

[BigGrizzly]

BUIZ, then that would make it at least 1 inch shorter then a 2 inch shorty on a stock Bravo installation. That answers a lot of questions on shorty applications I have encountered. Here it seems here they go for the 3 inch shorty applications. I have pulled my hair out on a 2 inch thinking it was a 3 inch shorty. Thanks for the info. I know YOU did the home work. It seems that last inch is a monumental difference! At least on two identical 24 foot V hulls on this lake with the same engines-within 15 Hp of each other(modified of course) measured on the same dyno.

[BUIZILLA]

IMO, the labbed cleaver with the stern jack will give best WFO speed and handling, the TXP will be the best midrange and *overall* best handling.... the round ear's with the stern jack are a hit-miss thingy,,,, unless the tab's are used

[Sam]

I've tried a lot of props with my 16/SS combo. I found that the Hydro OT was the best prop to date. I had mine tweaked to 24.5" dia..............good luck Lenny.

[Lenny]

Tomorrow I am putting the boat in and driving it out at 2000-3000-4000-and whatever it can turn, all trimmed up, GPS etc and making a baseline chart and using a digital transit for hull angle. Yes, really. :) as in degrees on the deck in front of the guages.

I am running the TXP and the labbed Cleaver.

The Stern Jack goes on on Friday. I will get the new numbers next week. Same fuel/driver/passenger and GPS. All the same.

Tiny little Lake here for this, thus two people. I will run out of water by the time I check the GPS and trim it some more and check again... then you all know how that ends up. :rolleyes:

[BigGrizzly]

Sam what other props have you tried? the TXP was released about 2 years ago as was the Fusion4. I am not doubting your opinion in any way shape or form. It is just that More and more people going in a different direction with newer designed props, especially on the shorter drive heights.