Help with I\O

[Mackzilla]

I have a Wellcraft 19SX Ecell and it came with the 4.3 vortec or thats what was in it I have taken it out and plan to fit a V8 down in it,Now I am no expert but no rookie either can someone give me some advice on HP to gear ratio to pitch on this particular boat? Any help is greatly appreciated, Also will trim tabs help me ,I am looking for a good ride but also some good holeshot and speed???? THANKS...

[flabum1017]

That boat probably has an alpha drive on it with a 1.87 gear ratio. most v-8's use a 1.5 ratio. You also don't want to put much more than 300 ponies to that drive either. So with lets say a 260 hp v-8 running on a 1.5 gear, with a roughly 3500 pound 19 footer... I'd start with a 14/21 prop.

[flabum1017]

Oh by the way, if you have'nt found a motor yet, I have a 5.7L vortec long block that I'd like to part ways with. Everything in it is new including the 4 bolt main block. I also might have enough parts to put together a Mercruiser TBI system with the ignition system too.

[Mackzilla]

Oh by the way, if you have'nt found a motor yet, I have a 5.7L vortec long block that I'd like to part ways with. Everything in it is new including the 4 bolt main block. I also might have enough parts to put together a Mercruiser TBI system with the ignition system too.How much for the vortec? Thats what my machine shop man said to look for.Also this is an alpha one gen II and its a 1:81 ratio...I was running a 23 pitch with the v6.

[BUZZIN' DOZEN]

Dude, I need to know how you came up with your user name!:D

Jeff

[Mackzilla]

Dude, I need to know how you came up with your user name!:D

JeffWell my name is Mack and then I just thought of that godzilla movie and said hey mackzilla sounds good,I have had this name for a few years now and its the same on all the forums I am on...Like Green hulk and pwctoday

[BUZZIN' DOZEN]

Just curious, Here's my "Zilla":D http://i27.photobucket.com/albums/c165/O-SIZE/Mackzilla.jpg

[flabum1017]

How much for the vortec? Thats what my machine shop man said to look for.Also this is an alpha one gen II and its a 1:81 ratio...I was running a 23 pitch with the v6.


If you were to keep that 1.81 gear, you will have to go to a 27 pitch or so prop. With a strong enough engine, you may out-rev the size availabilty in props and have to resort to re gearing the drive to a 1.5. Personally, I'd go to the 1.5 regardless.

[CharlieB53]

Check the waterline at the rear of that WellCraft, some of them sit at bit low in the water and have a tendency to leak at the cap seal.

Adding weight like replacing the V6 with a V8 will set just a bit lower in the water.

[Mackzilla]

Check the waterline at the rear of that WellCraft, some of them sit at bit low in the water and have a tendency to leak at the cap seal.

Adding weight like replacing the V6 with a V8 will set just a bit lower in the water.I havent thought of that but that is a very good point you just brought up..anyway to add ,how do you spell this, (bouency) anyway would there be a way to make it float higher like by adding some sort of flotation foam to areas or something?

[Mackzilla]

Just curious, Here's my "Zilla":D http://i27.photobucket.com/albums/c165/O-SIZE/Mackzilla.jpg
Dude that is awesome, Ive never thought of it but you know all the Mack drivers want that name on there truck,Looks like you have the jump on them my friend,,,,,Like I said Awesome truck you have there.

[Mackzilla]

If you were to keep that 1.81 gear, you will have to go to a 27 pitch or so prop. With a strong enough engine, you may out-rev the size availabilty in props and have to resort to re gearing the drive to a 1.5. Personally, I'd go to the 1.5 regardless.
well I was going to a high per. gear for the upper anyway so you say I will need to change to a 1:50 and this will be better ? I am not that good with gearing on these outdrives and I really hate to sound stupid but will this be like going to a lower gear or taller gear say if it waS a truck rear gear???

[bmax]

It's a taller ratio , actually ends up a 1:47 -1 . This is something you must change , as that poor little Alpha drive would eat itself with the 1:81 gears .
The lower ratio with a larger prop would would spin the drive too fast .
The gear change is fairly easy , it's done in the upper but you will need some special tools to shim it properly .
If you post the drive s# , i can give you part # for the gear set .
I would also guess a 23 prop .

[flabum1017]

When you go from 1.81 to a 1.5 you get closer to a 1:1 ratio. So, if you are running a 24 prop now, and put more power on the drive, you will need more picth, how much more depends on how much more power you add. Most stern drive props go up to about 29 pitch. If you put together a motor at close to 300 ponies, with the 1.81 gear, you will be at the high end of the pitch range and may run into problems finding a prop big enough. Going to a 1.5 gear, you will go back closer to the middle of the prop size range.
You can try the 1.81 with an assortment of wheels if you have access to them and see if it works for you.

[BUZZIN' DOZEN]

1st of all, welcome aboard, 2nd sorry to hi jack your thread, I just couldn't resist inquiring about your handle. But you came to the right place to ask questions, hope 'ya get your problem figgerd' out!:)

Jeff

[bmax]

Mack , i'm outta here as well . Listen to Flab , and you will be in need of a drive .
Good luck , and do some research .

[flabum1017]

Mack , i'm outta here as well . Listen to Flab , and you will be in need of a drive .
Good luck , and do some research .


I don't know how I offended you?

But now I feel compelled to reply to your post.

Your post saying that he would be spinning the drive too fast isn't quite right. The wot rpm of the two motors are within 200 rpm of eachother. In fact, the prop shaft will spin faster at the same rpm with the 1.47 (1.5) gear. He would however, be putting more load on the drive by putting the v-8 on it and a bigger prop. Even the extra load would not be enough to trash that drive unless he goes over 300 hp. The shorter gears are used in the v-6's because of the torque curve and hp, if you tried to run a 1.47 on a stock v-6, you would suffer top end speed because you would need a smaller prop just to get the boat out of the hole. The v-8 can handle the 1.47 (1.5) gear ratio better because they have the torque. As I said earlier, most v-8's came with the 1.5 gear unless it was put on a heavier boat, this is why they have higher ratios such as the 2.0.

[fkboatman]

I have a 91 maxum 20 ft cuddy that had 4.3 2bbl w/ 1.84 ratio drive, Installed a vortec 2bbl 5.0 in place of it. Went to a 23 p vortec prop and motor will turn max 5200 RPM over trimmed. Boat is a little stern heavy but no problems getting out of hole and on plain at all. Boat runs a solid 53 mph on gps all day long..........

[BUSHWACKER]

The alpha's don't like to have the power slamed to them nor salamed off them if you want them to live. Also alpha's did go behind BBC's at 330hp, in 87-88 they came out with the bravo and then went to 365hp cause the new drive could handle more.

[CharlieB53]

Adding weight to the craft results in more water being displaced for the boat to float, it simply rides lower in the water, just like carrying another fat ass like mine up the river.

Adding bouency, foam, just adds MORE weight, until you poke a hole in the boat and try to sink it! THEN the bouency/foam comes into play.

REMOVING weight is the trick, same as at the race track, the more weight we get rid of the quicker the car(boat) can run.

Float the boat, check the water lines, add weight, what you wouldl be adding iiwith the engine swap, and recheck the water line.

You may have to pull the rub rail, clean and reseal, silicone the cap.

[flabum1017]

I have a 91 maxum 20 ft cuddy that had 4.3 2bbl w/ 1.84 ratio drive, Installed a vortec 2bbl 5.0 in place of it. Went to a 23 p vortec prop and motor will turn max 5200 RPM over trimmed. Boat is a little stern heavy but no problems getting out of hole and on plain at all. Boat runs a solid 53 mph on gps all day long..........


Going from a 4.3 to a 5.0 wasn't much of a jump and keeping the 1.84 worked out for you. Mack has not told us what HP he intends to run, but a vortec 5.7 will put out 260HP+. Depending on how powerful he goes will dictate whether he need to go to the 1.47 gear. I think a nice 300HP setup will do him well.

Bushwhacker, I remember those BBC and Alpha rigs, and if you remember, the Alphas didn't do too well with the BBC's. I rebuilt many Aphas thanks to that setup (not complaining....made my money). The only reason they coupled the Aplha to a BBc was because they were in the middle of transition to the Bravo. They also had the 350 Mag setup that blew a lot of the Alpha's as well. You are right about the Alpha's being upgraded and able to handle more power, but I was assuming that Mack's was not a newer drive.

[fkboatman]

have a 88 searay pachanga in my shop now like that, we are swapping to Bravo for the customer now tired of blowing alpha drives. and its the 30 footer lol