Switching from inboard to outboard

[MATES]

I have a 22" starcraft cheiftain with a 4.3 mercruiser that I want to take out and mount an outboard on a pod instead. Anyone have any suggestions?

 

[henrye718]

Re: Switching from inboard to outboard

Definatly need some braces from the transom to the stringers like the OB version has and you need to make the transom just as thick and beefy 1 1/2 - 2" at least.

I believe the height of the transom has a alot to do with the leverage force that gets put on it by the outboard, hence the notching of the transom and not to many boats with a transom bigger than 20"

So the pod should adhere to this rule too i would think.

here is some more info.

http://www.marinepartsman.com/installing-an-outboard-on-your-boat.html

 

[henrye718]

Re: Switching from inboard to outboard

thinking about it in my head maybe you would even need a plate on the inner wall of the transom to be extra sure the bolts that hold the pod on do not pull through. Looks liek the pod adds even more leverage to the outboard and in different directions now too.

 

[tashasdaddy]

Re: Switching from inboard to outboard

many people have done this. but very few are happy afterwards. it totally changes the handling, and balance of the boat. i/o's are built differently than OBs different center of balance, etc.

 

[Rickairmedic]

Re: Switching from inboard to outboard

Mates welcome to iboats and ( once we see pics of your boat ) the Starcraft club . Theres quite a few of us Starcrafters floating around here . I would have to ask first off why you want to switch as it is even harder to do this swap on a Tin Can than it is on a fiberglass boat since you cant just fiberglass over the original hole in the transom. inboard engines are not that hard to come by and are generally cheaper to get and work on than an outboard .


Rick

 

[akoz]

Re: Switching from inboard to outboard

I'm in the process of doing this job on a 1974 18' Starcraft center console. I would not be too hung up on issues like center of balance on a boat like this. An equivalent hp outboard is going to weigh the same and in most cases, less, but reinforcing a transom made of a double sheet of 3/4" plywood (1 1/2") is a good idea. A knee brace (or 2) tied into the floor stringers is a fine (and cheap) piece of insurance.

Check my post titled "18' Starcraft center console 1974?" in this forum for some pics. I'm not finished and am in the process of building the bracing and trying to come up with a fairly simple splash well that doesn't take up the entire back of the boat and just about spoil the reason why I ripped out that hunk of cast iron in the first place!

Al

 

[akoz]

Re: Switching from inboard to outboard

I read this again and you mentioned a "pod". Was that already there or is this something that your adding/building? I only mentioned a fairly straightforward transom replacement. If you're talking about an extended stringer setup like in a modern bass boat, then your center of balance is going to start to come into play. I'd like to see a picture or drawing of what you're talking about.

 

[ondarvr]

Re: Switching from inboard to outboard

Replacing the current set up will be much cheaper, easier and faster, but if you really want to turn it into an OB then you can do it. Most OB and IO hulls on older boats aren't very different, if there's any difference at all, so that part isn't a big problem. If you use a floatation bracket then it makes it much easier to get it dialed in for good performance. Price out all the stuff before venturing down that road though, it can take many thousands for a good conversion.

 

[MATES]

Re: Switching from inboard to outboard

Thanks for the info. forgive my ignorance, but is a floatation bracket the correct term for what I dubbed a "pod"? meaning the bracket that holds the outboard is sealed thus adding more floatation? I will have to look into the price as you suggested. Just tired of the constant repairs on the inboard outboard. I travel long distances in remote country and get a little worried about breakdowns out there.

 

[xxturbowesxx]

Re: Switching from inboard to outboard

I'm in the process of doing this job on a 1974 18' Starcraft center console. I would not be too hung up on issues like center of balance on a boat like this. An equivalent hp outboard is going to weigh the same and in most cases, less, but reinforcing a transom made of a double sheet of 3/4" plywood (1 1/2") is a good idea. A knee brace (or 2) tied into the floor stringers is a fine (and cheap) piece of insurance.

Check my post titled "18' Starcraft center console 1974?" in this forum for some pics. I'm not finished and am in the process of building the bracing and trying to come up with a fairly simple splash well that doesn't take up the entire back of the boat and just about spoil the reason why I ripped out that hunk of cast iron in the first place!

Al

The problem is the engine(weight) will be hanging off the back of the boat instead of inside the boat which will effect the balance..

 

[henrye718]

Re: Switching from inboard to outboard

The problem is the engine(weight) will be hanging off the back of the boat instead of inside the boat which will effect the balance..

Arent all these starcrafts IO or OB the same hull just different parts to mount the engines?

 

[jonesg]

Re: Switching from inboard to outboard

The problem is the engine(weight) will be hanging off the back of the boat instead of inside the boat which will effect the balance..

Not if he uses a floatation bracket.
http://www.hermco.net/images/Lor0111.JPG

He will probably need a 30 inch outboard.
Plenty of guys on the classic seacaft site make their own from a simple screw together formica mold, they've got it figured out (or copied from the Hermco bracket , they usually set them at 13 degs if I remember that right.
http://www.classicseacraft.com/foru...7&page=0&view=collapsed&sb=5&o=&fpart=13&vc=1

 

[MATES]

Re: Switching from inboard to outboard

I was wondering about the weight being back further, is the balance you are referring to the fact that the weight will be back further and drag the stern of the boat down farther in the water with this setup (outboard) as opposed to the inboard outboard?

 

[jonesg]

Re: Switching from inboard to outboard

floatation brackets displace equal amount of water so the hull doesn't sit lower. If they're done properly they outperform transom mounts with the added benefit of the higher transom. They have to be bolted thru to the stringers with knee braces added.

 

[MATES]

Re: Switching from inboard to outboard

Makes sense to me. Thanks so much for the advise and info. I'm going to study it this winter and see what I come up with.

 

[Tacklewasher]

Re: Switching from inboard to outboard

Tried this with a Holiday.

After a couple of years of it not performing very well, and the hull getting hooked, I gave up, bought a supersport, moved the motor over and am much, much happier with the result.

 

[reelfishin]

Re: Switching from inboard to outboard

I've been considering doing the very same thing to a 1970 Starchief I found nearby. It's a solid hull but it needs a total restoration and the motor is seized from sitting for 20+ years. I had pretty much passed on the deal but after riding in one that was done with a custom swim platform and motor bracket, I was seriously considering it. I'm just not real sure I want a bigger boat. The one I was in had a full width motor bracket, swim platform made out of aluminum, it was through bolted to added knee braces inside. The transom was rebuilt with two layers of 3/4" plywood, then a sheet of heavier aluminum on the inside at all through bolt locations. The knee braces were taken from an outboard powered Super Sport that was parted out. The motor used was a 200 hp Mercury which made that boat downright fast. Keep in mind that setting the motor back changes the ideal mounting height as well, you will most likely be able to raise the motor up a bit. Since that boat really isn't built for speed, you most likely won't see too much of a change in handling, if anything, I'd guess it will be an improvement due to the weight savings.

The best part of the whole conversion is the full height stern and the abundant space you will gain over the I/O set up. It will be even roomier than a factory outboard boat since you will not need or have a splash well.

 

[akoz]

Re: Switching from inboard to outboard

Just FYI, here's a picture of what I've just done with my inboard to outboard conversion. Thanks, Al

 

[akoz]

Re: Switching from inboard to outboard

fyi, here's the transom capped off and the motor mounted

 

[APPALOOSA2]

Re: Switching from inboard to outboard

All transoms on I/O's are at least 1.75 " thick 2.0" maximum which is the minimum for Mercruiser outdrives to bolt up correctly to the engine. I don't care if its a fiberglass boat or aluminum or wood same thickness on the transom.

I would add quite a bit of support to the stringers to the transom for a outboard bracket on a Starcraft.