5.7 OMC stringer swap :)

[Keeganh]

I have read through the posts i could find here on this issue, people have said they are going to try and or have swapped out this drive but i have found little to no after the fact posts. so here goes, i have a 1985 Cobalt 19' CD in beautiful shape inside and out, has 300 hrs on everything, and runs like a dream. However, I am not a big fan of dead technology nor used parts off CL that fail an hr into a trip. I have heard tell of transom plate adapters but have not seen one online. my cobalt has a solid transom and stringers and the rest of the hull are in great shape, Cobalts came with a Transom and a hole was cut depending on purchasers desires. what is my easiest rout for a swap, would a king cobra unit bolt to my 5.7? am i going to have to rebuild my transom, find a prefab bracket, or fab my own? i like the engine and the ease of Maintence with the old carb and distro style. also before someone posts "but cobra is dead technology too" yes i get that, but aftermarket parts are much more available, and i am not interested in buying an entirley new drive system

 

[southkogs]

There used to be some "plate" type kits for OMC swaps, but I haven't seen 'em in a long time. To swap out the drive on yours, you're gonna' have to rebuild your transom and cut a new hole.

Dunno' about the rest of it though ... I think you're better off fighting your way along with the ole' Stringer or buying a different boat.

 

[Bondo]

Ayuh,.... Due to the differences, keepin' yer motor is not a very good option,...

To do such a swap in yer hull to preserve valve, ya gotta be lookin' at a pulleys to prop swap to a Merc or Volvo,....

Pretty much Nothin', but the long block of yer motor would be adaptable/ compatible with any sorta newer drive package,....

The transom is dealt with by glassin' in fresh wood into the hole, 'n recuttin' to match yer choice of new drive,....

No kits, no adapter plates I've ever seen,....

 

[superbenk]

You say it runs great & is in great condition so leave it alone & go boating! The Stringer is not a bad drive even though it's obsolete now. I had a Stringer & in some ways I miss it despite having a much newer & nicer Merc setup (see my signature). Much of the maintenance bits can still be bought new aftermarket without any difficult to keep things running smoothly. When you actually have a big problem with the motor drive then think about the swap but for now enjoy it. There's nothing inherently more unreliable in a Stringer than modern drives (especially Cobras).

 

[Keeganh]

so i reglass, find a doner or buy a new system, as far as mounting the engine, what packages would bolt to my current mount locations, this is another subject i have found 0 on, are there kits that replace or adapt for new mounts, of am i looking at another fab project to go with the transom? thanks fellas, this forum is invaluble

 

[southkogs]

so i reglass ...

Not reglass : rebuild.

The Stringer mounts to the stringers of the boat. Anything else bolts to the transom and puts all of the pressure transom - it'll push right through the fiberglass.

 

[Keeganh]

copy, Rebuild*

 

[Bondo]

as far as mounting the engine, what packages would bolt to my current mount locations, this is another subject i have found 0 on, are there kits that replace or adapt for new mounts, of am i looking at another fab project to go with the transom?

Ayuh,.... As I said, yer motor's dressin's, 'n the drive are one of a kind,....

Nothin' is compatible,....
No kits, not enough of Us fools doin' such things, 'n it's just as easy to fab up what's needed with resin, wood, 'n glass,....

I've done a few, 'n still got a few in various stages of refit,...

What ya gotta do it gut what's there, 'n build a standard motor bed, 'n drive cut-out in the transom,....
By today's standards, most everything fits into most all the same holes,....
The Merc keyhole has become the industry standard,....

 

[Keeganh]

Thanks Bondo, ill start saving for a pully to prop swap then, after searching for parts to my engine and drive go for a decent price in their condition if i want to part out, will make for a good winter project, thanks gents

 

[Bondo]

Thanks Bondo, ill start saving for a pully to prop swap then, after searching for parts to my engine and drive go for a decent price in their condition if i want to part out, will make for a good winter project, thanks gents

Ayuh,..... Start thinkin' junk rotten boat, with the driveline ya want,.....

Spring, but more so Fall is the time to be sniffin' 'round,.....

Little pieces co$t$ Huge money,..... a Donor boat has Extra pieces, big, 'n little,....