Upgrading drive to an Alpha, what can stay, what needs to go?

[soggy_feet]

Last year wasn't so good for me.
In the water for about 4 hours before I hit a rock, then spent the rest of the summer trying to find parts or fabricate new ones after shearing the driveshaft in my R drive.

I was thinking I was going to get it back together and in the water this spring, but the more I think about the time and money I've put into that dinosaur of a drive, the more I think I should just junk the whole thing and start new(er).


The boat is from somewhere around 1970, a Stardust Cruiser 40.
It's got a GM 165hp Straight 6, and the upper drive is Alpha-ish, but the lower isn't, and I bought and tried every bearing carrier for the prop shaft I could find, and nothing fit it.
Now it's half cast aluminum, half billet. Working in a machine shop has some benefits.

Engine smokes a little on startup, but runs well, so I'm ok with keeping that, or if I can find the right package deal, I'll pull that too, but at this point I'm planning around that powerplant.

If I want to fit an Alpha 1 to the boat, I'm going to need a matching upper and lower (can't mix gen 1, gen 2, right?), as well as replace the bell housing/transom plate, and some sort of engine coupler, correct?

What are the chances that my 25ft long steering cables and forward/reverse cables will be useable with a newer setup?

Anything else I'm forgetting?

 

[Bondo]

Re: Upgrading drive to an Alpha, what can stay, what needs to go?

Last year wasn't so good for me.
In the water for about 4 hours before I hit a rock, then spent the rest of the summer trying to find parts or fabricate new ones after shearing the driveshaft in my R drive.

I was thinking I was going to get it back together and in the water this spring, but the more I think about the time and money I've put into that dinosaur of a drive, the more I think I should just junk the whole thing and start new(er).


The boat is from somewhere around 1970, a Stardust Cruiser 40.
It's got a GM 165hp Straight 6, and the upper drive is Alpha-ish, but the lower isn't, and I bought and tried every bearing carrier for the prop shaft I could find, and nothing fit it.
Now it's half cast aluminum, half billet. Working in a machine shop has some benefits.

Engine smokes a little on startup, but runs well, so I'm ok with keeping that, or if I can find the right package deal, I'll pull that too, but at this point I'm planning around that powerplant.

If I want to fit an Alpha 1 to the boat, I'm going to need a matching upper and lower (can't mix gen 1, gen 2, right?), as well as replace the bell housing/transom plate, and some sort of engine coupler, correct?

What are the chances that my 25ft long steering cables and forward/reverse cables will be useable with a newer setup?

Anything else I'm forgetting?

Ayuh,.... The I6 was never used with the Alpha 1, nor the Gen.II,...
Marryin' the exhaust will be a problem,...

Go with a V6,.... Pulleys to Prop,....

 

[soggy_feet]

Re: Upgrading drive to an Alpha, what can stay, what needs to go?

That's too bad. It's a good torquey motor that didn't do too terribly with fuel consumption considering how much mass it was pushing around.

Thanks for the info. I'm gonna start looking in back yards for neglected boats, maybe someone will pay me to get their boat out of the yard...

 

[Bondo]

Re: Upgrading drive to an Alpha, what can stay, what needs to go?

That's too bad. It's a good torquey motor that didn't do too terribly with fuel consumption considering how much mass it was pushing around.

Thanks for the info. I'm gonna start looking in back yards for neglected boats, maybe someone will pay me to get their boat out of the yard...

Ayuh,... An Alpha 1, Will bolt to yer transom,... Just not the Gen.IIs,...

The SEI is 'bout $1500. here at iboats,..

 

[soggy_feet]

Re: Upgrading drive to an Alpha, what can stay, what needs to go?

I was looking for a deal on craigslist and I just found an 1984 Chaparral 235XLC, the guy said he blew the motor a couple years ago and left it on its trailer in a field by his house. We agreed on $500 for boat and trailer.

I tend to get myself into these 'more difficult than it needs to be' situations, but this MIGHT work out.

I'll get a trailer out of it that I don't need, and therefore can sell or scrap
I'll have newer hydraulics for the trim that someone destroyed on my boat (if it says non-serviceable, it's probaby for a reason).
Odds and ends fixtures/rails that I don't need and can sell or scrap.
And if that's a 350, they're plentiful enough to be able to rebuild and install it in my boat for a little bump in power (And scrap the old block).

The hull on my boat was replated from the transom going forward about 15 feet before I bought the boat, and with the motor mounts attached to weak/thin steel, and not to the newer steel plating, I haven't been able to hold engine/drive alignment and need to make some steel modifications anyway.
Might as well reconfigure.

Also found a 21ft food truck I might buy, but that's another story. Craigslist is a dangerous addiction.

 

[soggy_feet]

Re: Upgrading drive to an Alpha, what can stay, what needs to go?

Paid for the boat last night. It's a little over an hour away, so I wasn't planning on towing it home on that trip. Wanted to give the trailer a once over so I could show up prepared. Good thing. No straps holding it to the trailer, wire harness connector is squashed, and the tires are a little soft. No rot at least. Will go back tonight prepared.

Nice looking boat, a shame that it was left out like it was.

Drive was left in the raised position. Fingers crossed that it didn't freeze full of water and do any serious damage. Doesn't appear to have any from the outside. The brand new prop spins, so it's not full of water and rusted solid at least.

Engine and drive will both get full inspections before I start putting anything into my houseboat. Need to get it home first, and weld patch someone elses steel houseboat, and then make some dock stairs for someone else, THEN I can get into my boat.

 

[soggy_feet]

I've pulled almost everything out of the donor boat the last couple weekends.

I was told it had a bad head gasket, in reality, it wasn't winterized, and there's a crack in the block in the valley, another on the outside of the engine (same cylinder bank) below the exhaust manifold, and also on that side a split in the exhaust manifold. Block is toast, manifold I'll weld or braze.

Frustrating, but Im looking at it as buying a drive, transom plate, trim assembly, and a few odds and ends for $500, and it all arrived on a tandem axle trailer probably worth $2000 judging by the local craigslist ads.

SO, now I'm looking for a new block, and I find comments around the internet about the differences between pre-1987 Chevy 350's, and post-'87 motors.

I'm hearing that newer engines have thinner castings, the flywheel/flexplate has a different bolt pattern, then on top of that, I'm thinking about engine rotation and how that applies to whatever rotation my drive is (I don't even know yet).

Can anyone with knowledge of 350ci engines help set me straight? It's a Merc MCM 260 out of a 1984 Chaparrel

I've got the ability to accurately drill/redrill/tap holes if need be, but obviously, I'd rather find the most direct short block swap I can, acknowledging that I'm not going to find another marine engine for a couple hundred dollars, and it'll probably be an engine out of a truck. Maybe even from the '94 Chevy in my driveway that I never drive.