Will it hold up?

2 Horse

Cadet
Joined
Jan 25, 2010
Messages
16
Quick question if I may.
I have a Alpha 1 Gen ll with 1.5 Gears, looking to install a new 383 with
320 HP and 440 ft of torque. Will my drive hold or should I just run a 350 ?
Boat is a 20? Hot Shot, weight according to Baja web site is 2400 lbs dry
 

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
70,506
Re: Will it hold up?

Ayuh,... It'll depend Entirely on just how hard you abuse it...
 

2 Horse

Cadet
Joined
Jan 25, 2010
Messages
16
Re: Will it hold up?

Not looking to beat the hell out of it but, I have been known to push the limits every now and then.
 

mkast

Lieutenant Commander
Joined
Nov 6, 2002
Messages
1,934
Re: Will it hold up?

I was just wondering how old is the drive now?
Possible regear to 1.32:1.
 

achris

More fish than mountain goat
Joined
May 19, 2004
Messages
27,468
Re: Will it hold up?

Did somebody say....

[size=+2]GRENADE!!![/size]

That engine produces way too much torque for that small box... Merc put them behind 320hp big blocks in the 80's, but not for very long!

A modern 383 produces more torque than an 80's 454.... You do the numbers.... If you get more than a few hours out of it, I be surprised....
 

2 Horse

Cadet
Joined
Jan 25, 2010
Messages
16
Re: Will it hold up?

Then you're saying I'd be better off just running a 350 with say 310 HP and 360 ft of torque?
 

Don S

Honorary Moderator Emeritus
Joined
Aug 31, 2004
Messages
62,321
Re: Will it hold up?

I have been known to push the limits every now and then.

The Alphas have a design limit of 300 hp. What do you expect for an answer? Let me know, and I will type it out for you.
 

wca_tim

Lieutenant Commander
Joined
May 28, 2007
Messages
1,708
Re: Will it hold up?

Of course it will blow apart instantly!

wait, that is not my personal EXPERIENCE nor my observation of others. Run good lube, check it often, don't catch air under full throttle and don't worry about it. I would bet that the vast majority of teh drives that gernade from being overpowered... actually wouldn't have if they were maintained.

Besides, worst case is that you gernade a drive and order a new one from iboats or sei for 1200 or so...

my boat is probably about the same weight as yours and a little shorter.

I'm currently running 425-450 hp and probalby over 450 ft lbs torque through an alpha drive.

I also doubt there is much difference between 1.5 and 1.32 gears in terms of holding up - that's what merc tried to do to make alpha's live behind big blocks.

btw, I know people here on the river that are running over 500 horse through alpha drives, one that is probably over 600 with a blown smallblock and there are a number of people on some of the message boards that put that much power in front of them. what you're talking about is not rediculous by any stretch.

run good lube, change it often, enjoy it. imho...

ps. note that I have a set of new afr195 competition ported heads in the garage with larger combustion chambers. combined with thicker head gaskets that'll drop my compression to 8.4:1. I'm deciding between a procharger blow through and an overdriven 144 or 177 roots blower...
 

2 Horse

Cadet
Joined
Jan 25, 2010
Messages
16
Re: Will it hold up?

The Alphas have a design limit of 300 hp. What do you expect for an answer? Let me know, and I will type it out for you.

I thought the limit of 300 HP is at the prop not the motor. Drive eats about 25 HP but , I could be wrong. The real problem I think is the torque. Even a 295 HP 350 has 350 ft of torque. Just don't know how much torque a Alpha can handle.
 

2 Horse

Cadet
Joined
Jan 25, 2010
Messages
16
Re: Will it hold up?

Of course it will blow apart instantly!

wait, that is not my personal EXPERIENCE nor my observation of others. Run good lube, check it often, don't catch air under full throttle and don't worry about it. I would bet that the vast majority of teh drives that gernade from being overpowered... actually wouldn't have if they were maintained.

Besides, worst case is that you gernade a drive and order a new one from iboats or sei for 1200 or so...

my boat is probably about the same weight as yours and a little shorter.

I'm currently running 425-450 hp and probalby over 450 ft lbs torque through an alpha drive.

I also doubt there is much difference between 1.5 and 1.32 gears in terms of holding up - that's what merc tried to do to make alpha's live behind big blocks.

btw, I know people here on the river that are running over 500 horse through alpha drives, one that is probably over 600 with a blown smallblock and there are a number of people on some of the message boards that put that much power in front of them. what you're talking about is not rediculous by any stretch.

run good lube, change it often, enjoy it. imho...

ps. note that I have a set of new afr195 competition ported heads in the garage with larger combustion chambers. combined with thicker head gaskets that'll drop my compression to 8.4:1. I'm deciding between a procharger blow through and an overdriven 144 or 177 roots blower...



Just what I like someone that's testing the limits. If you don't mine sharing what gears and prop you running ?

How do you drive it ? rough, hole shots or just easy into it?

Thanks for all the info wca_tim
 

300sflyer

Chief Petty Officer
Joined
Jan 1, 2009
Messages
610

2 Horse

Cadet
Joined
Jan 25, 2010
Messages
16
Re: Will it hold up?

Have a look at these links.

http://northamerica.mercurymarine.com/engines/inboards/sterndrives/alphaone.php

http://northamerica.mercurymarine.com/engines/inboards/sterndrives/alphaone_specs.php

The most powerful "compatible" engine Merc lists for an Alpha drive, is a 350 Mag which has 300 HP, rather than 325.

Just my point. merc rates all drives at the prop. That's why when you look at the spec they rate a 95' 5.0LX at 205 HP when in reality it rated at 230 at the crank.
Not to get into a pissing match but I'm more interested in the torque it will handle. The 350 Mag has a torque rating of 380. So if one can handle that much, what is the max? you know they have a built in safe zone.
 

jaxnjil

Lieutenant
Joined
Aug 3, 2007
Messages
1,368
Re: Will it hold up?

I thought the limit of 300 HP is at the prop not the motor. Drive eats about 25 HP but , I could be wrong. The real problem I think is the torque. Even a 295 HP 350 has 350 ft of torque. Just don't know how much torque a Alpha can handle.


of any one here don is the last one i would question.


i asked much the same question as you a few years ago and got much he same answers. don explained this to me and i though i could baby, go slow yada yada and make the alpha work.

not counting the blown alphas before i got the boat i have gone thru 4. one about very 20 hours run time. if you enjoy getting towed in, fighting your boat off the rocks in the wind with no drive, loading dead at the ramp, and ruining vacations with a broken down drive by all means disregard all the above information and do what ever it takes for you to justify over loading your A 1.
 

basstracker219

Petty Officer 2nd Class
Joined
Feb 8, 2010
Messages
117
Re: Will it hold up?

Did somebody say....

[size=+2]GRENADE!!![/size]

That engine produces way too much torque for that small box... Merc put them behind 320hp big blocks in the 80's, but not for very long!

A modern 383 produces more torque than an 80's 454.... You do the numbers.... If you get more than a few hours out of it, I be surprised....

whats with the grenade thing?
 

300sflyer

Chief Petty Officer
Joined
Jan 1, 2009
Messages
610
Re: Will it hold up?

merc rates all drives at the prop.

Can you please point out exactly where on the Merc website it states that?

When I spoke with the servive manager, at Mercury Marine a year or so ago when I was looking to repower another boat, he told me the maximum "engine" HP to use with an Alpha drive was 300. He made no mention that a 325 HP engine was actually ok to use...

http://northamerica.mercurymarine.com/engines/inboards/sterndrives/alphaone_specs.php

In addition, look at which drives are compatible with the Mag 377 which has 320 HP. I dont see an Alpha there...

http://www.mercurymarine.com/engines/inboards/sterndrives/377mag.php
 

2 Horse

Cadet
Joined
Jan 25, 2010
Messages
16
Re: Will it hold up?

When I first started thinking about repowering I called Mercury Marine Customer Service looking for some spec on their Motors the rep told me that is the way they rate motors. All motor are rated at the prop, and he also said max on a Alpha Gen ll is 310 HP but that is the MAX and it means just that. I then ask about how muck a drive eats and the answer way 25 HP, so something say 315 or 320 is OK, answer YES. I also asked about torque but he would not give that info. Said Company Secret
 

wca_tim

Lieutenant Commander
Joined
May 28, 2007
Messages
1,708
Re: Will it hold up?

whats with the grenade thing?

Ever see the inside of an outdrive after it breaks running hard? bits of metal...

Also, remember that the weight of the boat has a HUGE amount to do with it. couple that with the fact that the harder you push something, the more important regular maintenence is. I wouldn't run one in a heavy boat - like many of the big block alpha boats that came unglued were. There are a los a good number of those that never did come apart...

alpha (and bravo, etc... for that matter) drives will take an almost amazing amount of abuse and neglect when you consider what they have to stand up to. If you're not pushing it very hard at all, then you can get away with letting the lube go longer, run low, etc... a lot more so than if you're turning it hard. The same is true for about anything. In other words, I suspect that in some cases neglect rather than overpowering was the real cause of a drive coming apart. Although I don't like to admit it, that has been the case with the drives I've had break...

I've been told by people who know, that once set up right, run an extreme pressure solid suspension gear lube. I like redline heavy duty shock proof. Amsoil makes a somewhat similar product. as an aside, try the redline product in your car, bike, etc.. tranny, differential, etc... you'll get a nice suprise...

or you can:

get more boat and drive

swap out for a bravo, etc.. for several thousand dollars

enjoy your boat the way it is - nothing wrong with this AT ALL.

Life's good this afternoon out in the shop - hope everyone elses here is..
 

300sflyer

Chief Petty Officer
Joined
Jan 1, 2009
Messages
610

wca_tim

Lieutenant Commander
Joined
May 28, 2007
Messages
1,708
Re: Will it hold up?

From your very first post in this thread.



You are wrong here too...

A 383 has 350 HP, and also lists only Bravo as a compatible drive.

http://www.mercurymarine.com/_media/pdfs/productbrochures/878312_Reman383MAG_SS.pdf

Good luck!!!

Oh... and have some extra rope on board so someone can tow you in.:p


I suspect he's not ordering a merc 383, but having one built or buying a crate motor.... the numbers he cited are pretty reasonable and would be measure at the crankshaft rather than the propshaft like merc numbers...
 
Top