What type of Alpha Drive? SS?
 

I bought an 87 Donzi Z25 with an Alpha drive and a 454 mag. Is this an Alpha SS or some other version of the Alpha?

looks like it has some sort of hydrofoil connected to the cavitation plate...

It does.

It's a Cobra Edge Pro Planing and Stabilizer Plate.

That is indeed an SS drive. Rough sand cast finish on the upper is a good givaway along with the CLE lower. The hydrofoil was probably to help the big boat plane with the short drives takeoff leverage (lack there of).

Do you want to sell it. JOHN

Fixx
 

their was one on speedwake a whyle back,dont know if its still available..their was a few on donzi.net also..

http://www.speedwake.com/newclassifi...p?product=1946

I am looking at a bravo 1 setup right now. If I can get it at the bravo at the right price I would want to sell it.

This drive has been great. No wave hopping or hard hole shots. I respect the torque of a BBC and know that it is my weak link. The Cobra Edge Pro Planing and Stabilizer Plate gets the boat on plane quickly but it does cause some drag. A bravo 1 would be a better fit.

Fixx
 

If you plan on getting anywhere near the speed with the ss drive you will want to look into a imco -2'' lower under the bravo upper..If you stay stock bravo then you will loose around 5 mph on the big end..

Would using an imco 2" lower keep me from having to do less transom work to mate the 454 to the drive?

Nothing to do with any transom work. He's talking about using a -2" lower unit (2" shorter lower unit) connected to a Bravo upper.

no the lower has nothing to do with mating to the engine you need to find a complete bravo with the gimble you'll have to pull the engine to install it all I think it should mount right up to the existing cutout I think you just have to drill two holes to mount it but you will have to run a seawater pump off the engine since your alpha has the pump in the drive unless you plan on running more power then what you currently have it may not be worth it

To go from an alpha to a bravo I'll need to drill 2 other holes and trim a little to mount the transom plates,right? Just want the x factor to stay the same. The ss is 2 or 2.5 inches shorter. The stock bravo would be deeper than the ss. My thinking was that to line everything up I might have to trim more of the transom.

I'm not exactly sure of what transom work is needed to change over gimble assemblies from a alpha to a bravo. If I was going to do this I would first put a straight edge against the bottom of the boat running back past the prop shaft and measure how much lower the prop shaft is below the bottom of the boat. Then I would install the Bravo and see what it measures to. Then decide if you want to go with a shorter lower unit. The Bravo is for sure going to be running deeper but if your talking about raising the gimble assembly in the transom to keep the same X it wouldn't be worth all the work as you would also have to raise the engine.

To change over to a bravo it's going to probably cost more than the boat is worth. A used bravo drive and transom assembly will be at least 5K. Then you have the water pump issue and if you go to a shorter lower unit that will be probably another 3K for a used one. And that's just for starters. Personally I would just leave that alpha in there. It's been there 24 years now.

Mr picklenjim, You just helped me make up my mind. The alpha will stay and the dream of taking off like a bat out of hell will just have to wait. Thanks. This is my 1st I/O.

give me a pm also when you want to sell the alpha

I think you have made a wise decision. This would be a good excuse to upgrade to another boat though. However it would be hard to part with that Donzi, their a fine piece.


I see the old Mississippi River Rat Plowtownmissle chimin in. What are you runnin one of them alpha's on that "Loose Change" boat ?

3 times its been on the river and I'm a river rat already? lol :drink:

Yeah, just an alpha1gen2 on it. It was stone stock this year but I've got a few things planned for it next year.

Dont give up yet.
I bought my boat complete minus engine for $4500
That included Bravo and external steering. I could have removed the drive and steering and still gotten most my money back for boat and trailer.
That would put me at 2500 for drive and trailer. Your SS will sell for at least that if not more. Then all you need is a couple grand for a used -2 imco.
My neighbor Doug (boatally insane on here) bought a complete boat with a fresh 454 and a Bravo for $3500, sold motor and trailer for $3000 and ended up with complete Bravo setup for $500
There are a LOT of deals out there if you have money in hand and the Alpha SS is so rare that people will pay top dollar for them even in these hard times.
Alpha to Bravo swap will take you an afternoon if you have all the parts and tools you need.Except for the hole for drive fluid the boats transom stays the same.

Personally I would not do the shorty lower until you actually run it with the bravo drive.
You may not lose mph if your current setup was never optimized prop wise.

I would have a GOOD drive guy go thru the drive.
If the gears are stock, have him put in the HD 1.50 gear set, and set up clearances carefully.
You can get rid of that wing plate by adding a touch of cup to the prop to help with getting on plane. Change drive oil every 10 hrs., and add a simrek drive shower, be sure to tell them it's an SS. Properly taken care of, these drives are not as weak as people think!
See pic to the left....

Hard to tell from the picture but is that a "Mirage" prop? If so, a Mirage Plus may help you getting on plane. The Mirage Plus has added cup to the prop tips. Helps getting on plane and carrys the bow a little better.

Fixx
 

I dont know it this would apply to your boat but the hydromotive OT 4 blade which is a out board prop works the best on a alpha SS drive..But thease props are being used on a 16' and 18' donzi classics with ss drives..

may want to do a search on donzi.net or inquire about it,theirs allot of info at this site on your boat,from what i read its not the fastest hull so you might just be pissing in the wind on props..

I had Mirage plus and it was still very hard to get on plane. I had the diameter brought down to 20.2 and just a little more cup added, it made a huge difference, boat planes faster, and mid range cruise is excellent. It's no rocketship but for the way I use the boat it works for me. Best top speed has been 65 with the current props.

The prop is a Mirage 23p. I found the numbers 86K112 on the lower, looks like there were 2 other digits in front of the 86 but I can't make the out. I think the the 86 is the year but I don't know what the K112 stands for. Anyone know?