Is there any hope???

[jkjkiefer74]

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?

 

[kenny nunez]

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]

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]

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]

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]

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]

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]

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

 

[Lou C]

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!

 

[*Rsf*RedNeck]

SHOTS FIRED!

 

[Scott Danforth]

you can bolt in any post 1986 truck motor.

the block, heads, crank and pistons are exact same as came in a TRUCK

cam is marine (however close enough to a truck to use the truck motor)

water pump, core plugs, head gaskets, all accessories on the front of the motor, ignition system and the induction are all marine

your motor is toast. it will cost you more to save the block than a new block is worth. seriously, it will cost you about $800 in machine shop labor and parts to sleeve the two cylinders and bore/hone the block and a brand new block is less.

now the better news. OMC has been out of business for a really really really long time

your 33 year old boat will have rotten transom, rotten stringers, water logged foam and other issues requiring a full restoration of the hull. that used to be $3000. however now with the cost of resin thru the roof and a 500% increase in lumber prices, that is closer to $4200

unless that boat has sentimental value, i would part it out and get a much much newer project boat. the 2000's are now up for new interior, engine work, etc.

 

[Lou C]

that, or just keep saving money.
think about cars and trucks, most of us wouldn't buy a 20+ year old car or truck and expect it to be usable, for daily use.
for my next boat I am not going any older than 3-5 years old, and outboard powered, ONLY.
Used but not used up. Once you get to 15+ years you are in the used up category and certain parts start becoming NLA for some of the early EFI systems and even some of the electronic ignition systems.
Now it makes you wonder if foam-cored composite boats will actually last longer than wood cored boats did, my impression is that they can, if built with good workmanship but I guess that is always the unknown factor.

 

[Grub54891]

Quote: think about cars and trucks, most of us wouldn't buy a 20+ year old car or truck and expect it to be usable, for daily use. : Unquote
Well I do. I'd take my 1999 jeep anywhere I'd please. No worries if properly maintained. Now a 20+ year old boat.... Totally different story. It's more than likely rotted. However my 1985 17.5 chapperall is solid yet and runs fine. She's a bit rough on the eyes but I don't care... Lol

 

[PITBoat]

Quote: think about cars and trucks, most of us wouldn't buy a 20+ year old car or truck and expect it to be usable, for daily use. : Unquote
Well I do. I'd take my 1999 jeep anywhere I'd please. No worries if properly maintained. Now a 20+ year old boat.... Totally different story. It's more than likely rotted. However my 1985 17.5 chapperall is solid yet and runs fine. She's a bit rough on the eyes but I don't care... Lol

That's weird though. But I do it too. The newest thing in my fleet is 16 this year. The oldest is 47.

Kinda fun running a 30+ year old boat (the prettiest one on the lake, IMO) with something similar but much newer, that can't catch you (but is obviously trying).

Kinda not fun though wondering when something's gonna blow back there that the bilge pump might not be able to keep up with...

 

[Grub54891]

That's weird though. But I do it too. The newest thing in my fleet is 16 this year. The oldest is 47.

Kinda fun running a 30+ year old boat (the prettiest one on the lake, IMO) with something similar but much newer, that can't catch you (but is obviously trying).

Kinda not fun though wondering when something's gonna blow back there that the bilge pump might not be able to keep up with...

Yeah but I know everything is fine. I do the bellows/inspections myself.

 

[PITBoat]

I did the bellows on mine, and the impeller, but I haven't changed any hoses.

 

[Lou C]

Quote: think about cars and trucks, most of us wouldn't buy a 20+ year old car or truck and expect it to be usable, for daily use. : Unquote
Well I do. I'd take my 1999 jeep anywhere I'd please. No worries if properly maintained. Now a 20+ year old boat.... Totally different story. It's more than likely rotted. However my 1985 17.5 chapperall is solid yet and runs fine. She's a bit rough on the eyes but I don't care... Lol

I do that too; we have a 1998 Jeep Grand Cherokee 4.0 that I bought new! Only 180,000 miles although some parts are getting harder to find and rust affects all these older Jeeps to an extent if you are in the rust belt. They are far simpler to repair than modern Jeeps that’s for sure. We also have a ‘17 Wrangler with the 3.6 V6 and it’s a different world from the old 4.0 inline six.
I use the ‘98 4.0 for local driving and the ‘07 5.7 Hemi for longer trips.

 

[Lou C]

P.S.: while the hoses on these last longer that on a pressurized system they still get hard over time. Tip:
Check the small hose between the P/S cooler and transom mount, I had this pop off one year overheated the engine and filled the bilge with salt water! That eventually led to my top end overhaul some years later. Also check the hose from the pivot housing to the transom mount.

Ever since then I go over every single hose make sure they’re in good shape and the clamps are tight.
I don’t think a bellows leak on a Cobra will sink the boat I had that once and there was really no excess water in the bilge.

 

[PITBoat]

I should be putting mine back together (un-winterizing) within the next few weeks. I'll have a closer look at that one going into the PS cooler. I remember seeing the other one when the drive was off. The ends of the large water pump one, and the one coming from the cooler are just a little iffy.

 

[LundAngler1650]

you can bolt in any post 1986 truck motor.

the block, heads, crank and pistons are exact same as came in a TRUCK

cam is marine (however close enough to a truck to use the truck motor)

water pump, core plugs, head gaskets, all accessories on the front of the motor, ignition system and the induction are all marine

your motor is toast. it will cost you more to save the block than a new block is worth. seriously, it will cost you about $800 in machine shop labor and parts to sleeve the two cylinders and bore/hone the block and a brand new block is less.

now the better news. OMC has been out of business for a really really really long time

your 33 year old boat will have rotten transom, rotten stringers, water logged foam and other issues requiring a full restoration of the hull. that used to be $3000. however now with the cost of resin thru the roof and a 500% increase in lumber prices, that is closer to $4200

unless that boat has sentimental value, i would part it out and get a much much newer project boat. the 2000's are now up for new interior, engine work, etc.

Quoting this so you have to read it again!

Sometimes a boat, car, truck, house, is just better off to be replaced, than it is repaired. Nobody except a whacko would have restored my Plymouth Belvedere, except for me, and I only did it because it used to be my grandfather's car, he purchased it brand new. It sat parked outside for 40 years before I bought it from my grandmother, after grandpa passed away.
When I bought my current home, it was the lot I loved, the house was a total loss, I just built a new home on the lot 300' from the original, I wouldn't even consider trying to restore the original house.