Is there any hope???

jkjkiefer74

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Joined
Apr 6, 2021
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3
I just acquired a 1988 Four Winns 235 Sundowner. Has the GM / OMC 5.0 engine and OMC Cobra outdrive. The person i got it from said was on the water near Miami Fl. when it just suddenly quit. No smoking, no noise said just quit. Its been sitting for at least 2 years. The pictures are of the #7 and #8 cylinders using a borescope. The other 6 cylinders are clean like the first pic. What im wandering is, is the engine worth saving or is it a total loss at this point?
 

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kenny nunez

Lieutenant Commander
Joined
Jun 20, 2017
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1,708
No matter how it cuts the heads have to come off. They may be rusted beyond repaIr. If the cylinders are really pitted from rust then a complete marine short block plus a set of manifolds will get the job done.
The original crankshaft may still be good along with the rods if you are handy with the tools the block could be bored with oversized pistons and a set of heads plus manifolds will work.
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
24,785
You need to establish how water got in there.-----Otherwise it may happen again.-----Also need to determine if you really want and OMC drive.-----If you need to rush to a dealer for every little hick up you may want to shop for another boat.-----Not easy these days as everyone seems to want to get into boating these COVID days.
 

jkjkiefer74

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Apr 6, 2021
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You need to establish how water got in there.-----Otherwise it may happen again.-----Also need to determine if you really want and OMC drive.-----If you need to rush to a dealer for every little hick up you may want to shop for another boat.-----Not easy these days as everyone seems to want to get into boating these COVID days.
Im pretty good at turning a wrench. Just new to the boating world itself. Ive been told to start at the exhaust. Check the risers, flappers and bellows. But my concern right now is .... if i can save the engine i have? How do i get the crystalized salt out? Ive been told white vinegar. Any input would be good. Keep in mind im an old dog learning new tricks...
 

Lou C

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Joined
Nov 10, 2002
Messages
7,241
If you already own it, then consider pulling the engine and evaluating the condition of it overall. If its an original engine and if used in salt water all that time, it may not even be worth rebuilding. I would pull the heads, see what you have then if it looks like the cooling passages are not totally jammed with salt water corrosion, it might be worth rebuilding, if so then a reman long block is your best bet. My experience with raw water cooling in salt water is that the cyl heads suffer more than the block. Keep in mind if used in salt (Miama Fl?) the intake manifold could be close to rotting through under the stat housing, the exhaust manifolds/elbows have to be replaced at 5 years intervals usually as well.
The Cobra drive is a good unit but its hard to find mechanics who really know them, if you like the boat and its in good shape you can always convert it over to a Merc Alpha when you have the engine out. I have one and I've been able to find the parts I need, I actually was able to pick up a spare drive and transom mount from ebay both in good shape.
 

jkjkiefer74

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Apr 6, 2021
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Like i said, im new to boating all together. Can any GM engine with a few conversions be used on a boat? Im talking about the long block portion.
 

Lou C

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Joined
Nov 10, 2002
Messages
7,241
What you want is the standard GM small block V8 , one piece rear seal, either pre Vortec or Vortec

All the accessories must be marine rated for safety including:
Starter
Alternator
Carburetor
Distributor
Fuel pump
 

jerryjerry05

Supreme Mariner
Joined
May 7, 2008
Messages
16,717
The newer GM blocks will be harder to adapt your older parts.
Before you spend?? do a real thorough inspection, heads, risers, manifolds etc.
Looks like you have the small camera for looking into the tiny spaces.
The Cobra was outdated the day they introduced it. :(
The good thing is there are a lot of them that people don't use and parts can be had.
They introduced the Volvo technology to the Cobra line and the dependability increased.
IF?? you don't have a lot of $$ invested?? maybe think about getting a Mercruiser or Volvo
powered boat.
If the new boat has an outboard? Remember, buy, Made in the USA
 
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Lou C

Admiral
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Nov 10, 2002
Messages
7,241
Jerry if the Cobra was outdated what is the Alpha, still a dog clutch with the impeller in the lower unit a pain to change compared to the Cobra which is the easiest one ever!
 
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