Just thinking out loud 383 stroker & an Alpha one

[harleyman1975]

I have a 20 ft bow rider with a 305 that runs great. I know I should just be happy but I wonder if my Alpha 1 would stand up to a mild 383...or is it not possible to build a 383 that would be safe to run through an alpha drive. the boat will do mid 40's at 4800 rpm as is ( 2003 regal 2000 w/305 2 bbl 19 pitch 4 blade aluminum). I wish it had a little better hole shot and some more top end.

 

[alldodge]

Don't see an issue so long as you ease into the throttle and not drop the hammer. Buddy has a 20 checkmate with 383 and extension box on an alpha drive. Been that way for years and no issues

 

[jkust]

I don't know what you consider a mild 383, but I would just expect that I would be spending some time off the water at some point fixing it. I am not a proponent for babying it because I didn't adequately address the build with the proper drive. If I'm spending the time on a 383, I'm not going to go mild, not going to baby it and not going to go Alpha 1. Sort all or nothing IMO.

 

[alldodge]

Just to clarify, its a light boat, not a heavy one.
Were not talking baby were talking not dropping the hammer. I have 11000 lb boat with 530hp on a B3XR and I don't drop the hammer on it nor do I drop it on my 4800 lb boat with a 454 and B1.

 

[harleyman1975]

Don't know much about the 305 as to what it is capable of. would simply putting a 4 barrel and intake do anything besides make it use more fuel? I know that the 305 does come as a 4bbl and a fuel injection engine. would I need to change the heads or are the stock (2003 factory) heads all the same? are these 305 "vortec" heads (lets just assume that they are original 2003 gm 305 heads). I know that there used to be 2bbl heads and 4 bbl heads with larger valves.

 

[jkust]

Just to clarify, its a light boat, not a heavy one.
Were not talking baby were talking not dropping the hammer. I have 11000 lb boat with 530hp on a B3XR and I don't drop the hammer on it nor do I drop it on my 4800 lb boat with a 454 and B1.

I'm a hammer dropper. If there's a hammer, it's getting dropped.

 

[Scott Danforth]

on a light boat, dropping the hammer with an alpha is not that hard on it. exiting the water and re-entering it does grenade the gear set.

I know plenty of people like AllDodge does with 383's alphas and extension boxes on boats with twins. run synthetic fluid. my buddy ran at least 10 years on his wiener boat with the combo before selling to get the next wiener boat with twin 540's with #6 drives.

ease into the holeshot, use a rev limiter to drop RPM's as you exit the water on a wave and you will be fine.

 

[Johnny hockey]

You do not need to change the heads to go from 2 to 4bbl. 305 is a solid engine. I would just stick a bigger cam, lifters, 4bbl, intake manifold, dbl roller timing chain some roller tip rockers on it and through hull exhaust. Do 3 angle valve grind, and port match your intake/ heads to the gaskets . That should get you 300 hp and can be done with the engine in the boat.

 

[Johnny hockey]

For about $1000.

 

[QBhoy]

Jeez...there is defo more performance to get out of your current set up...should be running into the 50's easy.
I'd start with getting rid of the 4 blade. Get an enertia or laser 2 on her and trim up.

 

[81manatee]

There is more power in that engine. It wants to move more air.. You absolutely could let it more air in with a 4v intake and carb and notice a difference.

 

[Blind Date]

I would't waste my time building a 5.0 V8. That's why I pulled the one out of my CVX18 and have a 5.7 ready to go in. Here's a SB 400 w/nitrous mated to an Alpha SS in a Glastron/Carlson CVX18 like mine. Think he's had it past 90 MPH which is why he put the hydraulic steering on. He's also running the heavy duty gears and a drive shower. Like AllDodge said with a light boat there's a lot less stress on the drive. I don't hammer the throttle on any of my boats coming out of the hole, that's just plain stupid.

 

[Chris1956]

Merc did mate Alphas with BBC engines. They were about 330HP.

 

[jkust]

I would't waste time my building a 5.0 V8. That's why I pulled the one out of my CVX18 and have a 5.7 ready to go in. Here's a SB 400 w/nitrous mated to an Alpha SS in a Glastron/Carlson CVX18 like mine. Think he's had it past 90 MPH which is why he put the hydraulic steering on. He's also running the heavy duty gears and a drive shower. Like AllDodge said with a light boat there's a lot less stress on the drive. I don't hammer the throttle on any of my boats coming out of the hole, that's just plain stupid.

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I will hammer my 5.7 but the Bravo 1 is unphased by only 300hp. It's not stupid, it's no big deal.

 

[alldodge]

Come on guys, lets take it easy. Were just voicing opinions, don't belittle anothers

 

[Blind Date]

An Alpha wouldn't be phased by your stock small block either. When your drive coupler fails prematurely from all that throttle hammering you'll know why. No big deal though, the part is relatively cheap and easy to replace once the motor has been pulled from the boat!.....LOL

 

[frantically relaxing]

The 21 Sea Ray in my signature, a friend of mine bought it from us in 2002 when we bought our (long gone) Sun Runner. After about 4 weekends of use the original 5.7 blew a head gasket, which partially filled the #5 while fueling up, and the engine fired before it hydrolocked. Broke all the main journals. Before the weekend was over he picked up a 4-bolt 350 from a work buddy and they installed it and finished out the season. Then he yanked it and turned it into a 383. He set it up for 11:1 compression. And another work buddy says "I have a set of Dart heads that should wake up that motor!" Buddy failed to inform him the Dart's were 56cc heads, what he was going to use were 72's. Boat ran like a raped ape. He was using 110 octane race fuel so there wasn't much knocking- at least that he could hear --before the first weekend was over he'd blown the hub out of the SS prop that served me well for 4 years, and also his 2 spare props. And he was losing the hubs at speed, not holeshot. He resorted to buying solid props for the thing. Had it to 59 mph once, at least. But- he didn't have 20 hours on it before the #1 cylinder wall cracked. He sleeved it, it lasted another year, then he broke another cylinder wall, only this time a chunk broke way and trashed the block. It was only after the teardown that someone told him about the heads, and that he'd been running 13-something :1 compression... then the boat sat for a few years, and I just took it back, and it now has a very low hour '83 5.7, which ran great last time I drove it...

So after several years of typical boating and a couple of years of enduring some fairly serious 383 power, the Alpha One took it all in stride. Build yours and don't worry about it

 

[Lowlysubaruguy]

The alpha and 305 powerplant are a great combination. Add much more torque and the drive may then suffer youll find some complaints with heavier boats or higher HP so my input try to get a little more out of your engine and live with what you have. Personally id put a new 350 GM vortec engine in place of any v8 that low end torque and reliabuility are primary goals. There is no fuel pump boss the intakes different and youll need a flywheel to work. But $1850 will get you a brand new car engine to the door. Id pick one to fit a 1998 2500 4wd truck loads of torque down low so you can run a prop that will get you to a decent top speed and still pull out of the hole and your cruise fuel mileage will be the best it can be. Next 2 brrl v 4 brrl. The 2 brrl is a gas hog they have large butterflies and feed lots of fuel at low to mid throttle you would get better mileage with a 4 brrl and overall better performance if your not a lead foot any way. Thats if you pick the right carb for your engine. Dumping a 650 or larger holley on it will not be efficient.

 

[harleyman1975]

Well If I were to "wake up" the 305 it would be with nothing larger than a 600 4 bbl and an appropriate marine cam. I am assuming this is a roller motor already so just new cam and lifters, timing chain and gears, 4bbl and intake. But stay with underwater exhaust I'm over 50. (nothing looks dumber than old fat guy trying to act like a kid). Checking out a 3 blade 19 pitch prop this coming weekend. Local prop shop is gonna let me try before I buy.

 

[jkust]

Well If I were to "wake up" the 305 it would be with nothing larger than a 600 4 bbl and an appropriate marine cam. I am assuming this is a roller motor already so just new cam and lifters, timing chain and gears, 4bbl and intake. But stay with underwater exhaust I'm over 50. (nothing looks dumber than old fat guy trying to act like a kid). Checking out a 3 blade 19 pitch prop this coming weekend. Local prop shop is gonna let me try before I buy.

My issue with waking up a 305 is how much extra hp it takes to really see a difference. For example the TBI version of my MPI engine was maybe 50hp less. Nothing to scoff at but my boat was made from 2001 to 2009 and in 2001 it came with TBI because MPI came out the next year. People with the 2001 TBI 350 MAG version of my boat who actually then bought the same exact boat a few years newer with the MPI 350 report little difference in power even though it is a 50hp difference.
So what...would you need 80hp to feel the difference, maybe 100hp? How much can you wake up a 305 then and still maintain marine specs meaning avoiding reversion? Heck even the tests that test the very same boat (can't think of the exact boats but have seen these tests) side by side, one with the 305 and the other with the 350 only show a little bit of extra out of the hole and a few mph on top end. Point being it takes a lot of power to really get appreciable differences.