Repower Questions, Alpha One Horsepower Rating

[greg82255]

Hello,

I currently have a 1986 Formula 206 Spyder with a Merc 260/Alpha One. It does about 50 on a good day, but I'd really like to get some more speed out of it (60??). The engine has 800 hours, and I don't want to invest a lot of $ into an old motor, so I am thinking of buying a long block at the end of this year and taking the good parts from my old motor (obviously only the ones that will bolt up), and replacing necessary parts. I've heard good things about long blocks from Rapido Marine, Jasper, and Michigan Motorz. Any thoughts on which one is best, or if there is another out there that is better?
I also really don't want to replace the Alpha drive if I don't have to (more $$$). I've heard they're rated for up to 300 HP, but I've also seen people running 454s with them. How much power can I really put into an Alpha drive, and what will happen to it if I run it over its specified limit? I've remanufactured 350's with 315 hp at the crank(probably vortec?). Would that be ok? Also seen 383 strokers with 350-400.. that would be ideal, but not if I'm going to ruin the drive. Any thoughts/concerns please post. Thanks in advance

 

[mkast]

Re: Repower Questions, Alpha One Horsepower Rating

Big blocks using an Alpha used 1.32 to 1 gearing instead of the 1.5 to 1 for the small block.

 

[greg82255]

Re: Repower Questions, Alpha One Horsepower Rating

If I can find an alpha with a 1.32 ratio, could I use a 383 stroker with it? I don't mind bolting on a new drive, it's the transom assembly that I don't really want to remove. I think I could buy a new alpha and sell mine without spending too much $.

 

[emilsr]

Re: Repower Questions, Alpha One Horsepower Rating

Big blocks using an Alpha used 1.32 to 1 gearing instead of the 1.5 to 1 for the small block.

They also were only 300-ish horsepower big blocks turning less than 4500rpm and they only did that for a year or two. There are lots of them still around though.

 

[Don S]

Re: Repower Questions, Alpha One Horsepower Rating

Alpha I's are rated for 300 hp.

 

[greg82255]

Re: Repower Questions, Alpha One Horsepower Rating

I've found a remanufactured vortec engine with 295 hp. Could I use my 1.5 ratio alpha or would I need to find a 1.32?

 

[mkast]

Re: Repower Questions, Alpha One Horsepower Rating

They also were only 300-ish horsepower big blocks turning less than 4500rpm and they only did that for a year or two. There are lots of them still around though.

330 horsepower, if they only lasted a year or two, how can there be lots of them still around?

 

[Don S]

Re: Repower Questions, Alpha One Horsepower Rating

Do you realize that Mercruiser came out with the Bravo drives because the poor little Alpha drives just don't put up with high torque and horse power very well.
They will work as long as your throttle hand doesn't go crazy. But that kind of defeats putting in the bigger engine doesn't it.

 

[greg82255]

Re: Repower Questions, Alpha One Horsepower Rating

I suppose you're right. I'm looking at a lot of $ to get a bravo setup, so I'll probably just get the 295 HP Vortec. If I can find a bravo setup really cheap, I'll get it, but I really doubt that will happen. I assume you also need lots of other new parts when you switch to a bravo (coupler, etc?).

 

[wca_tim]

Re: Repower Questions, Alpha One Horsepower Rating

My current perspective (for what it is worth... ;-))

1.5 ratio is fine for a "mild" smallblock. Sometimes i suspect that a good portion of the motivation
behind the 1.32 ratio was to push more cool water through the drive and provide additional cooling capacity for the engine It also provides less strain on the verticle shaft and hence gear sets.

Torque is what will hurt your drive - torque vs resistance to that torque represents the stress the gears (and other parts) will see, and strain represents how far things will deform as a result of that stress.

big block torq at low rpm, heavy boat from standstill = lots of torque, lots of resistance to speed increase (before getting on plane) = bad. small block, not as much torque down low before the hull is planing and so less stress is applied to the gears - especially for small light hulls. That being said, if you're going to get silly with power, use good lube, change it often and be prepared to buy a replecement at some point. by silly I mean 500 or 600 hp in a heavy boat...

 

[greg82255]

Re: Repower Questions, Alpha One Horsepower Rating

the boat weighs 3250 lbs, hardly big and heavy. I was thinking 325-350 hp max, and that much HP wouldn't even be seen unless I was at WOT, which I am never on for more than 10-15 seconds. I guess that's something to think about.

 

[NHGuy]

Re: Repower Questions, Alpha One Horsepower Rating

There are lots of alphas doing built up 350's, 355's, 383's etc. The smart ones don't rip out on full throttle holeshots, they get to keep their drives cause they roll on the power.

 

[ringmaster72]

Re: Repower Questions, Alpha One Horsepower Rating

I have around 375 HP and have over 100 hours on my alpha with a sb 355. No problems so far, just go for it. If you end up breaking the alpha just get one of the sterndrive units with a 3 year warranty.

 

[wca_tim]

Re: Repower Questions, Alpha One Horsepower Rating

What he said... I've got more like 450 hp running through an alpha drive in approximately 2200 pound, 17 1/2 ft boat... ;-) I know guys that have a good bit more than that. I've broken some things, but if I'm honest, it was my fault and a result of mistakes in maintenence, assembly, etc... I will say that U can tell a marked difference between the gear sets I've run hard in my boats and ones that I've got from other boats... what's the worst case? you put a fair amount of power in it, gernade a set of gears and then either upgrade to a bravo or spring for a replacement sei drive...

 

[joncrisler]

Re: Repower Questions, Alpha One Horsepower Rating

My 454 puts out 430-440 hp but mates up to a Alpha SS, which is significantly stronger than a regular Alpha 1. the stock 454 was 330hp and went 1600 hours, this one has about 200 hours on the more powerfull engine. Other than being resealed twice, it has proven reliable. I had an aquaintance with a 22 Sea Ray Pachanga with a 454 on a regular Alpha 1 - the engine was a warmed over 330hp 454 putting out maybe 350hp. He went through 2 drives over the years before learning to ease into the power.

Dont bother trying to find a Alpha SS- they are so rare that you would be lucky to stumble across one. It would also change your x-dimension as the drive sits a few inches higher in the water.

 

[wca_tim]

Re: Repower Questions, Alpha One Horsepower Rating

I've got news for you. Your ss drive is not really any stronger than a standard alpha drive. ALL of the internals aside from the verticle shaft are the same except for one verticle shaft which is just shorter. I have one that I broke taken apart and sitting on the bench waiting for me to make the time to put it back together...

My 454 puts out 430-440 hp but mates up to a Alpha SS, which is significantly stronger than a regular Alpha 1. the stock 454 was 330hp and went 1600 hours, this one has about 200 hours on the more powerfull engine. Other than being resealed twice, it has proven reliable. I had an aquaintance with a 22 Sea Ray Pachanga with a 454 on a regular Alpha 1 - the engine was a warmed over 330hp 454 putting out maybe 350hp. He went through 2 drives over the years before learning to ease into the power.

Dont bother trying to find a Alpha SS- they are so rare that you would be lucky to stumble across one. It would also change your x-dimension as the drive sits a few inches higher in the water.

 

[mkast]

Re: Repower Questions, Alpha One Horsepower Rating



Use of a Stern Jack, two speed propeller, drive shower and synthetic lubrication will help keep the drive alive.
The nice thing about the propeller is not having to hammer the throttle to get out of the hole fast.
This 330 horsepower/454/ Alpha (1.32 to 1) is in a 2950 pound (dry) hull for nine years.

 

[joncrisler]

Re: Repower Questions, Alpha One Horsepower Rating

I have a copy of the microfiche from about 1984-1985 which shows a significant number of parts that are different: upper and lower gear sets (same ratio 1.32 but supposedly stronger), drive shafts (shorter, stronger) and a few other bits. I also had a number of conversations with Merc back then about the same topic. Almost all of the internal parts are the same dimensions as a Alpha 1 as you said, but "supposedly" stronger according to my contacts at Merc back then. However, you could substitute a regular Alpha 1 gearset in place of the original one, and unless you exceeded its power limits, it would work fine. I think the bearings are all the same part numbers. I remember looking for a SS gearset for somebody back in the late 90's and they had been discontinued- my brother owned a boat dealership-Merc repair center. A seal kit from a regular Alpha 1 works fine on a SS, as does a water pump (except for the shorter water tube). I wonder if you have the original CLE gearcase ? That is interchangable with Merc's big outboards and was what you would use in place of the stock lower gearcase. Good examples used to be worth some bucks- I only recall seeing 1 change hands on Ebay and it commanded a premium price.
I have 1800 hours total now on that setup, 1600 of them behind a 454 330hp, and 200 behind a 430hp 454. I would say that setup is ok for about 400 hp if you dont abuse it with holeshots, but its no mystery why it was discontinued- the Bravo I is better and stronger.

 

[joncrisler]

Re: Repower Questions, Alpha One Horsepower Rating

View attachment 99665

Use of a Stern Jack, two speed propeller, drive shower and synthetic lubrication will help keep the drive alive.
The nice thing about the propeller is not having to hammer the throttle to get out of the hole fast.
This 330 horsepower/454/ Alpha (1.32 to 1) is in a 2950 pound (dry) hull for nine years.

View attachment 99664

I used a Land and Sea Torque shift prop on my Alpha SS- great concept but I kept breaking the prop cams, and they are finicky to tune correctly. But the holeshot was awesome

 

[wca_tim]

Re: Repower Questions, Alpha One Horsepower Rating

Sorry if my previous post came across as a little abraisive - it was not intended as such. All of the relatively few alpha ss drives were the same and had a shorter upper and cle gearcase modeled after the outboard speedmaster / cle lowers, right? The cle gearcase alpha lower is different than the outboard gearcase - it also has stronger alpha drive internals and was a little bit different casting. It is the same length as the standard alpha lower. The upper is shorter by 2 1/2 inches. There's no mixing and matching of alpha ss and regular alpha uppers and lowers (well, not with out some creative maching anyhow) You can bolt an outboard lower to an alpha ss upper if you shorten and respline the verticle drive shaft. I know some of the guys around here put alpha lower gears and bearing carriers in their outboard gearcases because they are stronger... or so they tell me.

The vast majority of internal parts are listed as the same part number from what I can see... aside from a few spacers, etc... and they certainly look the same for the drives I have taken apart right now.

The gear sets may have been stronger for the ss, but they sure look the same... I realize they could be a different grade of steel or hardened differently. I'll take a closer look at the upper dimensions for both and see if perhaps they made the upper drive casting around the bearing assembly more robust. Certainly since the lower shaft is probably the point wher emore deflection occurs, making it shorter and the housing around the bearing assembly(ies) could help quite a bit.

My real point was not so much that an ss drive is no stronger, but that a regular alpha drive is actually very strong - when properly maintained! If I'm honest, every drive I've broken has been my fault or failing on some aspect of assembly or aintenence. the harder you push something, the more rigorous you have to be about things like drive lube, etc... in my experience anyhow...

The alpha ss will eventualy go back together with a higher gear ratio and reinstalled with an outboard style surfacing prop, stern jack, extended bravo rams, hydraulic steering or steering stabilizer to ease the strain on the gimbal, bravo style through hull water pick-up and raw water pump and some other minor mods...

See if you can tell (without counting teeth) which is which of the following gear sets. Your choices are 1.84 standard alpha gears, 1.50 standard alpha gears, and 1.32 alpha ss gears... ;-) I need to quit farting around on the web and get some work done...

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