How much power will my sterndrive handle??

[81galaxiesport]

I recently bought an 1981 Galaxie Sport 18' with an 3.8v6 and OMC 800 series outdrive. At least I am 75% sure its an 800 series. I noticed that the pan has some oil in it and it appears to be leaking from the Timming cover, and the rinky dink fitting that is tapped(but not welded) in the oil pan for the dip stick tube. I am the kind of guy that likes to have plenty of power but am far from rich. Kind of a catch 22 I know.
What ever the case, I have been looking at some SBC's for a swap considering I would rather not spend $$ on the 3.8. My main question is how much is too much for this stern drive. Can I do a mild build say like 300-350hp and be ok with the outdrive I have?? I spoke to GS Marine( Greg Schumaker) and he has a built up 305. But if I am going to do a SBC I figure why not just do the 350.

Any input you guys can offer would be great. This is my first boat, it is in awesome condition with only 239 orig hours. It has been garage kept and I am the 3rd owner. Previous owner was a friend but he is clueless when it comes to mechanics.


Thank you!!

 

[Bondo]

Re: How much power will my sterndrive handle??

I recently bought an 1981 Galaxie Sport 18' with an 3.8v6 and OMC 800 series outdrive.

Ayuh,..... Sorry to hear that,....

For various reasons,..... Your Plan just Won't Work.....

Most of the Parts for that drive are getting Rare, or are NLA.....

Loose the old Stringer drive,+ about Anything is possible.......

 

[jerryjerry05]

Re: How much power will my sterndrive handle??

If you go to more power you will have to change the gearing in the drive.
Those old OMC are junk and gonna cost a lot to re-do and keep in good shape.
A rebuilt motor 305 or 350 is only 20=25hp difference between the two.That also depends on what has been done in the overhaul.
If you want to fo faster then get that boat running and pawn it off on someone. Then buy a Mercruiser with a v-8 in it already. They can handle more power that an OMC.The newer OMC are better but expensive.The new OMC/VOLVO are a good bet. The older 275/270/280/290 Volvo drives are made to handle over 700hp.
I have worked on the older OMC before but won't touch one now. Good luck Jerry

 

[81galaxiesport]

Re: How much power will my sterndrive handle??

Ayuh,..... Sorry to hear that,....

For various reasons,..... Your Plan just Won't Work.....

Most of the Parts for that drive are getting Rare, or are NLA.....

Loose the old Stringer drive,+ about Anything is possible.......

I appreciate the advise, but I am pretty stoked on the boat. Its super clean, it runs great besides the oil leaks, has low hours. I am just always hungry for more power. I am a proud owner at this time. Maybe down the line I will replace the stringer, but what is soo bad about them that your sorry I purchased the boat. I got it for $1500. The trailer is in great shape and probably worth close to that alone.

 

[81galaxiesport]

Re: How much power will my sterndrive handle??

If you go to more power you will have to change the gearing in the drive.
Those old OMC are junk and gonna cost a lot to re-do and keep in good shape.
A rebuilt motor 305 or 350 is only 20=25hp difference between the two.That also depends on what has been done in the overhaul.
If you want to fo faster then get that boat running and pawn it off on someone. Then buy a Mercruiser with a v-8 in it already. They can handle more power that an OMC.The newer OMC are better but expensive.The new OMC/VOLVO are a good bet. The older 275/270/280/290 Volvo drives are made to handle over 700hp.
I have worked on the older OMC before but won't touch one now. Good luck Jerry

Thank you for your honest and respectful answer Jerry, Maybe I like things sugar coated but, I am pretty stoked for how good of shape the boat is in and for my first boat the price was right.


I have the chance to pick up an older boat with a rebuilt Berkley Jet and a olds 455Ci for VERY cheap. I am not a jet fan but if it is going to save me thousands on an outdrive and enable me to have a funner faster boat than I may be in. What do you think??

 

[81galaxiesport]

Re: How much power will my sterndrive handle??

Ayuh,..... Sorry to hear that,....

For various reasons,..... Your Plan just Won't Work.....

Most of the Parts for that drive are getting Rare, or are NLA.....

Loose the old Stringer drive,+ about Anything is possible.......

BTW I am pretty technical guy. Can you elaborate on the limits. I would greatly appreciate it!!

 

[1976 Slickcraft]

Re: How much power will my sterndrive handle??

I`m running a pretty healthy small block Ford thru a 1976 OMC electric shift drive in a 19 foot boat. I put my motor at around 240 HP. Had zero issues with the drive. Gotta be crazy with the maintence though.
Jesse

 

[Bondo]

Re: How much power will my sterndrive handle??

Ayuh,...

If you Really Love the Hull,....
Scrap the Stringer,+ drop in Anything else....

I've done a few,+ have been involved with many more Refits...
The most economical to do it to buy a Donor Boat with the driveline you Want....
Then just swap it all over to the Prized Hull....

I've got an Old Town Canoe Co.'s flagship of the 1970s,.. The Atlantis.... a 25' cuddy cabin..
It had a 351 Ford,+ drive just like your's when I got it...235hp rated...
They also came with 327s,+ 350s,.. The 350s were 260hp I believe....

Btw,....

I spoke to GS Marine( Greg Schumaker)

So how hard was Greg laughing when you told him you wanted to Hot-Rod an Old Stringer Drive,..??..??..??..??

 

[81galaxiesport]

Re: How much power will my sterndrive handle??

Ayuh,...

If you Really Love the Hull,....
Scrap the Stringer,+ drop in Anything else....

I've done a few,+ have been involved with many more Refits...
The most economical to do it to buy a Donor Boat with the driveline you Want....
Then just swap it all over to the Prized Hull....

I've got an Old Town Canoe Co.'s flagship of the 1970s,.. The Atlantis.... a 25' cuddy cabin..
It had a 351 Ford,+ drive just like your's when I got it...235hp rated...
They also came with 327s,+ 350s,.. The 350s were 260hp I believe....

Btw,....


So how hard was Greg laughing when you told him you wanted to Hot-Rod an Old Stringer Drive,..??..??..??..??

I think that is why he offered a 305ci. Seems like the limit anyone runs is 240hp. He didnt say much besides come bring it in and let me take a look. He has helped a couple of buddies of mine with their project boats. The more I look in to it the more I see why people are stating to buy another boat if I want more. I may just use this thing as a stepping stone instead of pour money into it right off the bat.
I am probably just going to fix the oil leaks and call it a day. Use it for a bit then sell it and make some money from the deal to "upgrade". I appreciate the help. If anything I may swap a 305. Just depends on how long this motor lasts. But with only 239 hours on it I may as well rag this motor out a while longer...

 

[Bondo]

Re: How much power will my sterndrive handle??

Use it for a bit then sell it

Ayuh,....

That would be much Better if done Sooner rather than Later......

If it Breaks,...... You'll pretty much be SOLuck.....

 

[81galaxiesport]

Re: How much power will my sterndrive handle??

actually I found a whole stringer 800 for 400 in working order so if anything happens, I know they are available

 

[CrownlineTN]

Re: How much power will my sterndrive handle??

$1500 was really cheap for a boat with that low hours. You could turn it over for a profit and use the money for an upgrade. With this many folks concerned about the drive, might do that before it fails rather than waiting until after.