Merc. 1 to Alpha Gen II

Got a freind looking at what appears to be an early seventies Starcraft Cheiftain (similar to Islander) with a 165 MerCruiser (in-line 6).

The price is right $500.00/inc. decent trailer. The hull is good, just needs paint and TLC. I can do that.

The boat is missing the transom assembly and drive. The engine and all the parts that mate to the transom assembly are sitting on a pallet. I think a previous owner was looking at a repower. We can rebuild the engine, if need be. I'm a fan of that power in the Islander/Cheiftain.

The question is:

Will a MC Alpha Gen II trans. assembly and drive bolt up to the old 165-six?

We can get either a Gen. I or Gen II trans. assembly and outdrive very reasonably.

Also, I believe we need a 1.50:1 ratio? Is that correct? If not, which one?

This boat is definetely worth redoing and it is exactly what he wants. He's willing to put several grand into it. Still a bargain.

Re: Merc. 1 to Alpha Gen II

Will a Gen II work, probably not.
Exhaust opeing to Y pipe (single pipe for inline), inner transom plate probably different, outdrive shaft length. I see a lot of possible problems with it.
Have never tried it personally, so won't say it's a fact.
You are skipping over the Alpha one drives, going straight from the old One Drives to an Alpha I Gen II. Nothing is the same.
You also need a 1.65 ratio for an inline 6, the 1.50 is for a V8.

Re: Merc. 1 to Alpha Gen II

We can get Gen I. That's not a problem.

I just thought that going to the most modern would be of benefit. Don't have to.

It sounds like the Gen I is a direct bolt up???

Thanks for the ratio info.

Re: Merc. 1 to Alpha Gen II

The R, MR, and Alpha drives are also a lot different from the older 1 drives. Still can't say if it will work, I've never tried it.

Re: Merc. 1 to Alpha Gen II

Don S said:

The R, MR, and Alpha drives are also a lot different from the older 1 drives. Still can't say if it will work, I've never tried it.

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Hmmmmm. Maybe I need to not take any chances and go back to a 1 system. I'm sure there are a few around. We'll look.

Or, we'll look for COMPLETE engine drive packages. Probably 4.3L. I'm sure we can figure out the engine mounts.

I BELIEVE the Volvo SX and DP transom cutouts are the same-RIGHT?

If we go that route, we'd prefer Volvo.

Thanks.

Re: Merc. 1 to Alpha Gen II

DJ said:

I BELIEVE the Volvo SX and DP transom cutouts are the same-RIGHT?

Click to expand...

The SX and DP cutouts are the same but I'm not sure if they are the same as the "old" Mercruiser cutout.

Re: Merc. 1 to Alpha Gen II

Reel Poor said:

The SX and DP cutouts are the same but I'm not sure if they are the same as the "old" Mercruiser cutout.

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They are the same.

Re: Merc. 1 to Alpha Gen II

Ayuh,....

DJ,.. There Are in fact ways to mount any of the motors mentioned to any of the drives mentioned...

Some of the Issues,+ Some of the workarounds are,...

Going with the Mod.1 of course will be a drop-in,+ Go....

Going to the Alpha 1,... will require changing the complete Transom assembley,..
And using the Alpha 1 Flywheel Cover, Coupler,+ a down-pipe from an Alpha 1 In-line motor...And I'd go with the Newer trim System...
The reasons are,
The Flywheel cover has the rear motor mounts, which are 9" wide on the Alpha 1s,+ later, where the Mod.1s are 15"... Also, with the Mod.1s, the input shaft for the drive is 8"(in-line motors),+ with the Alpha 1s, it's the standard 9" shaft...

Going to the Alpha, Gen.II is pretty much the Same Swap, requiring the Same parts,...
Except,... You'll need to drill 2 more mounting holes thru the transom,+ Probably do a little Tuning to the cut-out with a diegrinder, Maybe...

And,... Depending on the size of the Flywheel on the I-6,.. There Might be fitment issues if it's the 12" Flywheel, trying to mount the Newer Couplers,.. But again, it's Not a roadblock, just a detour...

I yanked the 140hp, Mod.1 from My Islander almost 10 years ago,+ went with the Alpha 1, 4.3LX....
It's been No lookin' back ever since....

And,...
The Best Advice possible is to buy a Donor boat to scrap out....
It'll save you Tons of Ca$h buying all the little bits,+ pieces that you never get with a component swap....

Re: Merc. 1 to Alpha Gen II

Bond-o said:

I yanked the 140hp, Mod.1 from My Islander almost 10 years ago,+ went with the Alpha 1, 4.3LX....
It's been No lookin' back ever since....

And,...
The Best Advice possible is to buy a Donor boat to scrap out....
It'll save you Tons of Ca$h buying all the little bits,+ pieces that you never get with a component swap....

Click to expand...

Thanks Bond-o, great information. A lot to think about.

I'm with you, swap to a 4.3 LX or a Volvo SX or DP, even better. There are used packages out there, if you look hard enough.

Either would be a stellar package in this boat, like yours.

BTW, what did you have to do to the hull to change from the 4 cyl. to a V-engine?

Re: Merc. 1 to Alpha Gen II

If you ever found a Volvo 4.3L with DP-S package, (SX Style drive) we never would be able to wipe the smile off your face.

Re: Merc. 1 to Alpha Gen II

Don S said:

If you ever found a Volvo 4.3L with DP-S package, (SX Style drive) we never would be able to wipe the smile off your face.

Click to expand...

I'm thinking the same thing.

A new one can be had for $10K-complete. In my mind, it would be worth it. You can't buy this boat or repalce it for less than $15-$20K (decent). Plus this one can be completely "customized" to suit the new owners needs-exactly.

The best part about this whole deal is that it's NOT my money.

Re: Merc. 1 to Alpha Gen II

BTW, what did you have to do to the hull to change from the 4 cyl. to a V-engine?

Click to expand...

Ayuh,...

I bent up a set of motor mounts out of .090 aluminum,+ Pop riveted them in,...
Jigged up the motor on an alignment bar,+ measured,+ built shim blocks out of p/t plywood,..
Glued up about 3"x4"x8" bolted to the aluminum,+ the motor mounts lagged in from above...

If you go that route,... I'll snap a few pictures for ya...

Re: Merc. 1 to Alpha Gen II

Thanks. Sounds very doable. If a "package" is what we go for, I'll be in touch.