alpha power limit

[daved]

Can anyone give a bit of advise on the amount of h.p an Alpha can take? I am thinking about a 425 h.p carb motor. I amd a very gentle driver off the line but I do like running flat out every now and then.. I have an 86' 22C
Thanks,
Dave

[Carl C]

My experience is limited here but I don't think it will last long.

[JamesT]

Can anyone give a bit of advise on the amount of h.p an Alpha can take? I am thinking about a 425 h.p carb motor. I amd a very gentle driver off the line but I do like running flat out every now and then.. I have an 86' 22C
Thanks,
Dave

I was told by Mercury that the HP rating for the alpha one's is 305hp i have a bone stock 22zx with a 350 mercury mag rated at 300hp and i have broke a few of them.But i don't baby it.I don't think it will last very long at all with 425hp in front of it.

[Rodger]

My SB 406 in a 16' popped a couple of Alphas. Never dynoed the engine but I'm guessing about 400H.P. I never did hard accelerations, just W.O throttle occasionally.

[mrfixxall]

Merc use to put a big block in front of them,i have a friend that has a 1987 baja 235 dvx with a Big Block and a alpha,it lasted for years but the drive had 1.36 gears in it..TMDOG is running a 383 with close to 500 hp through his SS drive,,as long as your easy on it and use redline shock proof gear oil it should last..

[Traveler]

Supercharged 383, over 500 ib-ft of torque from 2500 to 5800 on the dyno, classic 18. Have run it over 4 years with no breakage but some wear at the pins. Don't hammer it out of the hole or when it's out of the water. Frequent spells at WOT. Saying this is probably the kiss of death!

[Planetwarmer]

I have an all original 1987 454/Alpha 1 combo. 200+ hours, no problems yet. I replaced the gimble bearing for fun, and the u-joints were in great shape.

[osur866]

Supercharged 383, over 500 ib-ft of torque from 2500 to 5800 on the dyno, classic 18. Have run it over 4 years with no breakage but some wear at the pins. Don't hammer it out of the hole or when it's out of the water. Frequent spells at WOT. Saying this is probably the kiss of death!

What speeds you seeing with that set-up? You running 3 or 4 bladded props on the Alpha?

[daved]

Thanks for all of the info. I need to think about it before I place the order but I am leaning in the direction of making the switch.
Thanks,
Dave

[Fishermanjm]

make the switch dave or start buying spare alpha drives now

[Pismo]

3 blade props, lower pitch, higher end of rpm range, will help. Take it easy. Small block 425hp is easier on drive than big block 425hp.

[smidgen too]

Just my 2 cents,, Back in 1989 to 1991 my friend raced this APBA A class Magnum copy [@ 5500 lbs] with twin 450hp 350 chevys & Alpha drives. This boat won 28 races, one over all National high point winner,, and one National championship with only breaking one Alpha drive vertical shaft. And anyone who knew Ken,, knew he didnt do much mantinace other than oil changes on his drives. I believe back then Merc also put the 454 330hp & the 350 320hp EFI with the Alpa drive.

[MOP]

I also have a 22C it was originally a Tempest 300 w/Alpha some say 300 at the prop don't know for sure, it now has a 383 with a Bravo a mistake I have regretted ever since. For what it cost me to convert from the Alpha to the Bravo I could have easily replaced the Alpha four times with brand new SEI drives which carry a 3 year warranty!, not only that the bravo will cost you 3 MPH having a bigger case profile. Most people ruin their Alphas by hammering them out of the hole and soft shifting them. They like to be slammed into gear, soft shifting rounds the clutch dogs causing them to pop out of gear at speed!

[OFFSHORE GINGER]

Hey guys i have been trying to post this from the start with bad luck which never seems to come up ,and this site is ................ http://www.rlcboats.com/ (http://www.rlcboats.com/) .....or www.rlcboats.com (http://www.rlcboats.com) that advertise a 650 hp Alpha drive rebuild . Hey guy's i am only posting this for $hit's and giggles and welcome your replies .

[MOP]

Hey guys i have been trying to post this from the start with bad luck which never seems to come up ,and this site is ................ http://www.rlcboats.com/ (http://www.rlcboats.com/) .....or www.rlcboats.com (http://www.rlcboats.com) that advertise a 650 hp Alpha drive rebuild . Hey guy's i am only posting this for $hit's and giggles and welcome your replies .

The whole spiel is here some us have followed this guy off and on for a couple of years.

http://www.donzi.net/forums/showthread.php?t=64346

[JamesT]

I also have a 22C it was originally a Tempest 300 w/Alpha some say 300 at the prop don't know for sure, it now has a 383 with a Bravo a mistake I have regretted ever since. For what it cost me to convert from the Alpha to the Bravo I could have easily replaced the Alpha four times with brand new SEI drives which carry a 3 year warranty!, not only that the bravo will cost you 3 MPH having a bigger case profile. Most people ruin their Alphas by hammering them out of the hole and soft shifting them. They like to be slammed into gear, soft shifting rounds the clutch dogs causing them to pop out of gear at speed!

Actually i think you made the right decision,i went the SEI route and am now regretting it.I broke 3 of the SEI drives,and yes they do stand behind the warranty and replace them no questions asked,but you have to eat the shipping cost and wait a couple weeks to get the new one, and not to mention removing and replacing the drive.Next thing you know season has passed by and you've spent most of it working on your boat.I am switching to a bravo and still have around a year and a half left on the SEI warranty. I will glady sell the brand new SEI alpha to someone interested.

[The Hedgehog]

Actually i think you made the right decision,i went the SEI route and am now regretting it.I broke 3 of the SEI drives,and yes they do stand behind the warranty and replace them no questions asked,but you have to eat the shipping cost and wait a couple weeks to get the new one, and not to mention removing and replacing the drive.Next thing you know season has passed by and you've spent most of it working on your boat.I am switching to a bravo and still have around a year and a half left on the SEI warranty. I will glady sell the brand new SEI alpha to someone interested.

I have the 383 Bravo Combo and love it. Drop me a line, my dad may take the Alpha for his 4.3.

[mphatc]

MR FIXXALL gave the right answer . . REDLINE LTW SHOCKPROOF gear oil . . I used this on my 1986 Chapparal 2350SX, ran it HARD, lots of air time in big waves, never had a problem with the drive, but wore out two gimbal rings . .


Mario L.

[Planetwarmer]

Keep in mind, its not the high speeds that kills drives, its rough throttle techniques and the drive leaving the water.

[daved]

This is a lot of great info. It seems to me that with my driving style I should be ok with the alpha. I am easy on the take off and do not do wave jumping. My family has been talking about a better boat to spend the day on but I love this 22c. This is one of ther reasons why I am up in the air on spending 6k on a new motor. I think they got spoiled spending time on my last boat, it was a 2000 32' Regal and we loved it. We are going to the N.E Boat show to see if we like anything but I really want to stay with a Donzi. I have been checking out the zx line from Donzi and really like the set up on these. I tend to rush into things so i want to go slow.
On another note, I looked at an 87 22c I saw on CL in NH. The boat is in really good condition, no cracks at all that I saw. It has been sitting for a couple of years but has new paint so it looks good. The motor is a 7.4 with a bravo. I think he wants 12k with the 2000 ibeam trailer.
I think this is a bit high but might be worth a look.

Thanks,
Dave

[Carl C]

the drive leaving the water.
:yes: I'm sure that's what killed my Bravo X. The combination of a shorty lower and running 2-3 footers with an occasional 5 footer thrown in for fun is not kind to drives and you will not always be able to synchronize the throttle. I'm pretty sure that the guys who get the Alphas and even Bravos to live don't see a lot of air time.

[joseph m. hahnl]

Hey guys i have been trying to post this from the start with bad luck which never seems to come up ,and this site is ................ http://www.rlcboats.com/ (http://www.rlcboats.com/) .....or www.rlcboats.com (http://www.rlcboats.com) that advertise a 650 hp Alpha drive rebuild . Hey guy's i am only posting this for $hit's and giggles and welcome your replies .

AH Yes: Triple Digits and his chopped Alfa. You got more than a Giggle here :rofl:

[fegettes]

This has been an interesting subject for me since I am in the final stages of installing a 450HP 383 in to my Sport with the intentions of utilizing the original Alpha with a drive shower installed. I do not forsee hammering it out of the hole, and not really interested in running WOT that much, but to be able to cruise at a much higher speed at 3,000 RPM's.

My next subject is to find the appropriate prop for it.

Steve

[craigdskilling]

It looks like the 383 is the engine for the 18 donzi.I also just put a 383 carb into my donzi and love it last year with my alpha drive 1:50.ratio.I was running a 25p mirage plus labbed to a 5800rpm.with the 383 they like higher rpm but i didn't like it that high.I can't tell you the top speeds but it was fast for the short blast.I didn't want to take the chance that my drive could blow up so i am putting on a blackhawk drive this summer.so that takes that worry out of play i hope.If things go to plan i should have a a pretty fast donzi and kool looking i think.so if you are going to do a change there is lots of options.craig:)

[craigdskilling]

Sorry just read that it's for a 22 that works too.

[Conquistador_del_mar]

This has been an interesting subject for me since I am in the final stages of installing a 450HP 383 in to my Sport with the intentions of utilizing the original Alpha with a drive shower installed. I do not forsee hammering it out of the hole, and not really interested in running WOT that much, but to be able to cruise at a much higher speed at 3,000 RPM's.

My next subject is to find the appropriate prop for it.

Steve

Steve,
I know some of the guys here will think that a Hydromotive QIV would be hard on an Alpha drive, but they have wonderful cruising characteristics along with very good top end performance. A guy wrote me back about a set of them I sold to him last year that his cruising speed went up 8MPH at the same RPMs, and that it was the best $500 he had spent on his boat. Just a thought, Bill

[fegettes]

Steve,
I know some of the guys here will think that a Hydromotive QIV would be hard on an Alpha drive, but they have wonderful cruising characteristics along with very good top end performance. A guy wrote me back about a set of them I sold to him last year that his cruising speed went up 8MPH at the same RPMs, and that it was the best $500 he had spent on his boat. Just a thought, Bill

Thanks. I will start looking for one.

[8318]

I am running a Hydromotive 27 " 4 blade on my 1983 18.
Pushing it is a built up Dart 400 and a Alpha SS.
boat runs in the low 80s any time I want it to.
We tested over 10 props when I built and instaled this Dart 400 in the boat.
The Hydromotive was BY FAR THE BEST!!

[clayman]

What do you guys think about that guys cut down alpha drive? Is that a feasible option to create a shorter drive, or is he way out in left field? Cut, weld, shorten shaft, re-spine shaft, pick up 8-10 mph? I have decided after this weekend run with some other boats, I need more speed.

[clayman]

so is this "triple digits" guy full of S? took a 55 mph boat and hit over 100?

[smokediver]

Wow Clayman , longtime ! That trippple digit guy is a little out there but I havent met the guy so who knows .. As far as the alpha , I had a 383 in my 16 ... I went through 3 uppers , each one let go at 2500 rpm . I did finally put in the HD gearset and that held .

[clayman]

Id like to here from the Donzi owner with the 18 on his site. I am going to go on a quest to get 80 mph out of mine. I have enjoyed the boat for ten years with basically no problems and no breakage. I've only done routine maintenance. I am going to do some trial runs, document my speeds and settings, and start a new thread. I am going to stick with the alpha drive. I have an extra I am thinking I can experiment with, shortening, nose cone etc. I am also working on a external steering setup.
I thought it was funny on that guys site how he started out presenting it as a project on a budget, then quickly adds steering, then who knows how much on a new motor etc.

[hdsadey]

So what is the major weakness of the alpha? Lack of cooling in the upper breaking down the oil and scalding the gears and bearings? Is the bearings the problem or the gears? I'm very curious as to which parts are failing!

[MOP]

An Alpha can last a long time, it should have a shower and good oil. The biggest killer for "all" clutch dog drives is people that put them into gear slowly, babying them into gear rounds the clutch dog engagement dogs. Once the dogs round off enough the drives will slip in and out of gear at speed grenading the upper, I have seen many most of which blew at normal cruising speeds. Learn to snap them into gear with one clunk if you can hear a ratcheting sound you are shifting to slowly! These drives have proven them selves for many years, walk down the docks and look at the many fair sized express cruisers. You will see a ton with Alphas that have a lot of time on them.

[joseph m. hahnl]

So what is the major weakness of the alpha? Lack of cooling in the upper breaking down the oil and scalding the gears and bearings? Is the bearings the problem or the gears? I'm very curious as to which parts are failing!

Shock force. The gear set is relatively small. Big torque , big waves , hole shots with big pitch and"yes" also heat and oil break down. All can contribute to failure. I would also suspect that the alloy is slightly soft and shears.I'm not exactly sure what makes a Hd gear set stronger, but if I were to take a guess , the alloy and hardness has been changed. In the old days they put in a lower ratio gear 1:32 to compensate for big block torque. Today you can get an HD gear set for the 1:5 ratio. For High torque, a 1:32 heavy duty gear set should have longevity.

http://bpi.ebasicpower.com/c/MER4A/graphics/00000001/GLM11210.jpg (http://bpi.ebasicpower.com/pc/GLM11210/MER4A)

[younger]

From my experience I have had 5 alphas 3 gen I, 2 gen II. all but 1 had the 1.32 gears all behind built sbc from 350 to 415 cubes. When they were built I always put used gear sets that had run time on then and set them up tight babied them the first few hours. No hole shots or wave jumping, but lots of high speed runs. One of the advantages with the alpha is an internal cooler which I made. Take the top cap off the drive pull the casting rubber plug, drill the cap above the plug location on a slite angle forward. Tap hole for a 90 degree fitting pointing the fitting at top bearing in the cap. The drive always is getting cool water pumped from the drive water pump. A perfect 90 fitting is the brass one in the distributer cap of a merc dist. Engine cooling was never an issue. Remember at boat cruising rpm 2500-3500 is where most motors produce peak torque.

[younger]

Pics of alpha cooler. The removal of the rubber plug improves volume of water and cooling to the top of drive.

[mphatc]

All excellent comments . . younger, I like the cooler idea . . never seen that one before!

I'd like to add that what you use for lubrication is the most important . . Mercruiser lube is old technology . . you should be running a 100% synthetic gear lube.

In my last Alpha I ran Redline LTW Shockproof, changed it every year . . this boat was 2350 Chapparal that I ran hard, sold with over 400 hours 6 years ago, and still running strong in salt water with the same fluid program at 650 hours.

The boat that won the last Around Long Island race was a 30' Sonic with twin Alphas! An old boat that was run hard in that race!

Mario L.

[joseph m. hahnl]

you should be running a 100% synthetic gear lube.

In my last Alpha I ran Redline LTW Shockproof,
Mario L.





use redline shock proof gear oil it should last..


http://www.racerpartswholesale.com/images/uploads/4585_1707_large.jpghttp://www.racerpartswholesale.com/images/uploads/4587_1708_large.jpg

Which one is better? I'm thinking heavy duty:yes:

[biggiefl]

I ran a 1987 Baja 240 with a 454 pushing 400hp for 20+ years and NEVER had the outdrive apart. All good points here and the best is making sure you are off that throttle when you land or she won't last long. I ran into the driver for Team baja a few years back at the Sarasota races and he has the same boat(personally) as I did running 450hp with an alpha and gave me the same advice. He also said that Mercury would only rate the Alpha at 330hp(with 1.32's) due to warranty but they said off the record 450+ if you do as we have said. With 1.5's...dunno!