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'1986 251 I/O conversion to twin O/B's

The boat is outside, under a carport waiting on me and its driving me ape **** nuts!

The Mrs is waiting on me to paint the inside of the house we just bought and Im scheming on how to get time in the boat ;)

Mark, fill the hole from the drive, build/attach/glass a longitudinal across the top of the transom on the inside (did this on the last Sonic and was a huge improvement) then knees from inside transom to stringers.

Goal is for it to look factory when done.

Karzrus, fingers crossed that theyre still good. Previous owner replaced the floor over tank and would hope he checked while it was opened up.
One I do the 454ectimy, Ill also pull the tank to inspect.

Im anal on projects like these cuz in my mind, theyre only fun at 9/10+ in chop and I dont want to worry about me or my passengers being safe.

Ask SCT.
I broke a ram on a Bennett tab on my first 24' Sonic, giving him a ride in Lake Erie chop.
 
Do you have a boat?

Yea.. kinda... More like parts of a boat. I had a thread going on here about the rebuild, but stopped updating it when Photobucket screwed everyone. One day I'll sit down and redo all the pics. In the meantime I have a duplicate thread in OSO under transom replacement on checkmate 281.... The project may have spiralled out of controle....,
 
After waiting till April (weather) to start my new shop.......(ugh), its done and Im in and so is the boat.
Didnt get any free time to start tearing stuff apart until a couple wks ago.

So far so good, and no real surprises.

Found there is 10" of foam forward of the fuel tank. This equates to approx 10 more gls of fuel.
I was considering making this a step down to cabin, aiding entry but I dont like the shift in weight that moving the tank back would create and, at this point the additional fuel capacity is more important to me.

The motor beds came out intact, rock solid and bone dry.
And they're 32 yrs old!

Floor over tank was recently replaced and was reattached to stringers w/2" pan head screws and NO sealer on them. Bottom of that section of floor already has evidence of water intrusion, so w/the screws driven into the top of the stringers how long until they rot?
When they do, is it the wood/Checkmates fault

Had to remove to the cabin bulkheads to access forward portion of floor for removal.
No idea what will go back in but it wont be these.

One huge engineering challenge for this project is adding an opening hatch over the cabin doors (as the 24' Sonics had) which will require complete removal of helm/dash area.
Still pondering that one.

Built a new pod for the controls.

Motors are bought ('98 250 hp V-6 looper OMCs w/250 hrs that I used to own) and paid for pending an inspection by Paul. Assuming that passes, probably road trip to La. for motor p/u in Nov.

Plan to finish tank removal today. It has severe corrosion on top so I'll have to determine if can be expanded safely or needs replaced.
Hopefully there are no hidden (rot) surprises bellow it. Top of stringers tap solid.
 
Pix's

Sorry Chris, missed the memo about my membership expiring, meaning I couldnt post pixs above.
I know a bunch of members have gone to facebook but Im done w/it and I think many others are/will also and will be back here.

Anyhow,

The tank came out today.
The good is I thought I drained the fuel when I brought it home and had not, and drained 40+ gls out of it that the truck and the Mrs's Jeep is now running on.

The bad is the tank is junk due to corrosion.
 

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demo day

misc pixs
 

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moh pixs

Now its a project!
 

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the trash can full of foam brought back memories of when I redid the floor in my 251...mine weighed well over 100 lbs soaking wet ! great job !
 
Worst part was the stink of the water that ran out of it.
Ugh!

Local (high dollar) fab shop finished quote on motor bracket and it was way more than I hoped.
Being the skin flint I am, I either find a cheaper (hungrier) shop or I build one from glass. The good is, I think I already have enough cloth/resin to build it.

Was also looking at building a glass tank if alum was too expensive. I thought I could change resin type and be safe w/ethanol laced fuels.
My suppliers said...., nope.


the trash can full of foam brought back memories of when I redid the floor in my 251...mine weighed well over 100 lbs soaking wet ! great job !
 
No, you want a aluminum tank...seen some nice aluminum engine brackets as well, my CC has a real nice one and have seen the same one for twins
 
Used to be many builders that used glass tanks.
They were fine until the addition of ethanol to our fuel.
I had heard there were resins impervious to it. My glass supplier says no.


On brackets, Ive had both aluminum and glass.
I prefer alum but am having a tough time swallowing the prices theyre asking for them.


No, you want a aluminum tank...seen some nice aluminum engine brackets as well, my CC has a real nice one and have seen the same one for twins
 
New tank is on order and due next wk.

After much math and experimenting, Ive decided on a 95 gallon (their math says 93) tank to replace the OEM 67 gal tank.

Basically, it will run from cabin bulkhead to within a foot of the transom!
I wanted a true 100 gls but that wouldnt have left me w/enough room in the bilge for the bilge pump.

Dont like carrying 586 lbs of fuel but I do like having access to 93/95 gls.

Most of prep work is done in preparation for the tank.

Today I plan to lay out the transom knees and install them before I begin construction of the motor bracket.

The good is, stringers are solid and most of the **** work is done!

Bought a load of steel tube to build another stand for the motors.
The good is, I got to practice my welding skills.
Bad is, I still suck.
 

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Glad you incorporated that fill to the front for your setup.

It's probably my only gripe about my boat - having it at the rear.
 
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Glad you incorporated that fill to the front for your setup.

It's probably my only gripe about my boat - having it at the rear.

Yep
Previous owner could only get 45 gls in orig 67 gl tank due to same issue.

Making good progress.

Hull is prepped for new tank which is due this week.

Figured out, mocked up and started transom reinforcement.

And due to quotes in brackets, I’m building my own, out of glass.
 

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