I/O (Sterndrive) Conversion to Outboards

[redneck joe]

looking at crap upside down kills me. I have a hard enough time looking normally....

So, two splashwells.

 

[tpenfield]

Ted, are you going to build boxes on teh little wings for boarding ladders?

View attachment 413136

No, I already have 2 boarding ladders on either side of the swim deck that will remain intact.

 

[redneck joe]

To save me from searching thru 20 some pages can you post a pic of the mock up, attached to the boat, right side up? I thought you were eliminating the swim platform

 

[tpenfield]

To save me from searching thru 20 some pages can you post a pic of the mock up, attached to the boat, right side up? I thought you were eliminating the swim platform

Sure . . .

 

[tpenfield]

another illustration. . .

 

[Willyclay]

. . . everything is about +/- 0.1", better than I expected.

Wow! Good on ya, mate!

 

[tpenfield]

It seems like winter has arrived . . . 37˚F today

I have started to map out the access holes, which will be at the transom face and the top plate which mates to the underside of the swim deck.

For the transom . . . I was initially thinking that 18" diameter would be OK, but perhaps 20" is going to be better. The larger the hole, the smaller (less height) the top & bottom stingers would be. The holes in the top plate would be about 8" . . . enough for an arm to fit in.
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Either way (18 or 20") it is going to be a bit of a contortion to get enough of my body through there for final fabrication (some fiberglassing) of the inside, installation (bolts), and maintenance (bilge pump). Not sure if there is a 'minimum' type of size used in structures, etc.

Thoughts?

 

[Scott Danforth]

Ted, maybe use a rounded off squarish hole?

17" x 17" with 4" radius would give you more open area than the 18", similar to that of the 20".

 

[redneck joe]

I like Scott's idea, still get strength from rounded corners. What is your belt size? Or belly size, whichever is larger.

 

[Scott Danforth]

What is your belt size? Or belly size, whichever is larger.

Ted likes beer..... although he is skinny compared you you and I.

 

[tpenfield]

I have great ambitions of loosing 20 lbs. before boat launch.

I like the rounded corners idea . . . came up with this . . . 5" radius corners. . . . they look like they will retain decent strength at the corners. Probably will be big enough for me. The purple lines are where a 4" stringer grid will be installed, so that the bolt flange has got some muscle to it. The transom of the boat will have a matching grid.
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[tpenfield]

Hole-y extension pod . . .

I got the access holes cut. There will be 4 additional holes closer to the transom for accessing the engine mount through-bolts. Probably going to order the deck plates before cutting those holes for an assured fit.
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I think my bod will fit through the transom openings. Now I got to rip some Coosa to 4" width for the stringer grids.

 

[Scott Danforth]

dont forget the tube for the rigging hose. on aluminum ones, that is welded in. on your fiberglass one, that would be glassed in.

 

[alldodge]

dont forget the tube for the rigging hose. on aluminum ones, that is welded in. on your fiberglass one, that would be glassed in.

Good point


Where you going to place them?

 

[Scott Danforth]

Ted shows them in the one pic.

 

[redneck joe]

So im sure you've done the calcs but the removed weight of i/o blocks raises the stern same as added ob weights on an extension, keeping overall attitude the same? Will you be adding fuel cells in extra space?

 

[tpenfield]

So im sure you've done the calcs but the removed weight of i/o blocks raises the stern same as added ob weights on an extension, keeping overall attitude the same? Will you be adding fuel cells in extra space?

Covered in a few places in this thread, but to summarize . . .

Boat looses about 500 lbs of weight. CoB (center of balance (CoG) moves back about 9". The buoyancy added by the extension pod will raise the stern (at rest) about 2.5".

No additional fuel tanks . . . The best place for fuel tanks is near the CoG. The engine bay space will be used for storage (and move some weight aft as needed)

 

[tpenfield]

More Progress . . .

Transom grids are in place . . .
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[flashback]

So those access holes will be duplicated in the boats transom yes?

 

[tpenfield]

A few more progress pictures and some questions . . .

I have the transom pieces to cut-out today and then focus on gussets and stiffeners, most of which I'll pre-form and add after the initial fiberglass layer.

Questions Du Jour:

• Rigging tubes . . . Inside diameter (ID) ? 2" . . . 3" ?
• Transom access plates (round deck plates) 6" or 8" ? I'm going to buy them now and pre-cut the openings to the proper size before glassing.
• Fiberglassing . . . any thoughts/ideas on fiberglassing the internal structure? (I think the exterior of the structure will be easy in comparison to the inside)
• Web holes/cut-outs in the main structural member . . . worth doing?

Picture Updates . . .

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TIA for input on the questions and anything else.

(BTW - the Admiral asked how much this things is going to weigh . . . I didn't want to tell her )