Cracked Block...

[bullsnot]

I've winterized my boat for a number of winters and follow the procedures to the letter but I really screwed something up this time. Long story short I froze my block.

I've rebuilt many street motors but never a marine motor and never a motor that has been frozen. From what I can tell it froze on one side only. The exhaust manifold is cracked but I already ordered a new one. The block however has a 5 inch crack in the middle towards the top and is protruding slightly out. I'm not sure if I forgot to drain the one side or if I opened the drain but gunk in the block prevented it from draining completely. Probably just missed one side.

Where do I start? Is it possible the it only blew outward can be welded? New block only and rebuild with existing internal parts? Possible damage to internals? Must be a marine block?

 

[alldodge]

The main key to winterizing is when you pull the plugs, stick a screw, wire or something up in side and wiggle. Do it again after all water has drained, just to make sure.

A block for a truck/car is the same block used by a boat, but the differences in marine motors is a truck motor and not from a car (different cams). The rest is brass or stainless core plugs, and composite head gaskets.

I would suggest either finding a donner boat and get the motor from it, new or remanufactured long or short block. The easiest would be the long block.

You can rebuild your own, but the block is toast, don't even think of trying to fix it

 

[bullsnot]

Thanks AllDodge. That confirms what my instincts were telling me. I guess now it's just a matter of deciding to rebuild or just buying a long block and being done with it.

 

[bullsnot]

Quick question. If I use all my marine internal parts such as crank, cams, composite gaskets, brass plugs etc is there any reason why I couldn't use a bare block from a street engine?

 

[alldodge]

Quick question. If I use all my marine internal parts such as crank, cams, composite gaskets, brass plugs etc is there any reason why I couldn't use a bare block from a street engine?

Agree with one caveat, I would not reuse the core plugs or head gasket. Core plugs are dirt cheap and can be found at a local auto store, and head gasket should never be reused. Crank and cam, reuse without a problem so long as they meet tolerances (have machine shop look at them). Probably do not want to reuse pistons and no way reuse rings

 

[bullsnot]

Thanks again. I'm thinking I might just pick up an auto short block and switch out the cam (new correct for application), core plugs (new), and marine head gasket after checking heads for warpage. Any reason that wouldn't work?

 

[alldodge]

If your getting a new long block just get a marine one and not have to do anything else. Even your local GM dealer can get marine engines. Many have bought them from Michigan Motorz.

What size motor you need, 350 or 305, oh and what year?

 

[bullsnot]

Sorry, thought my sig was updated. 350, 1988. The only thing is a marine long block vs an auto long block cost about 1k more. Seems cheaper just to switch out a cam, plugs and head gaskets.

 

[bullsnot]

Instead of a long block though I think I may just do an auto short block and change the parts mentioned previously after checking heads for warpage.

 

[km1125]

It's just a little leak right? Just get a bigger bilge pump!!

**NOT**

I agree with the others... don't try to re-use that block. But before you just go replace it with same, are you really 100% comfortable with the performance? Not sure what you have in the boat and how you use it, but spending just a few $$ more to upgrade to something more substantial is something to kick around now better than anytime else.

 

[alldodge]

Yep, looks like Michigan wants 2300 for a long block. I did google "1988 350 marine short block" and came back with a few sites. Found one (not recommending) Mabbco which has a 2-bolt main and roller cam (no lifters) for 700 and no core required.

If your in fresh water then the head gaskets is not as big a thing as salt, still can pose problems over the long term. Suggest calling the local junk yard for a truck motor, or contact the local machine shop and I would know a source to get one

 

[bullsnot]

Haha...my dad suggested I just a second bilge pump! He was kidding....I think?

Oh I'd love to spend a few extra bucks and add a few more ponies, believe me. Problem is that it would probably destroy the current OMC drive. You can update the drive but I'd rather dump the cash into a newer boat. I was gonna sell it the spring and just buy a newer boat. Think I'll fix this one and stick to the plan.

Alldodge I found the exact same thing you did. Think I'm gonna spring for the that small block you mentioned.

 

[Scott Danforth]

Get an LKQ pull-a-part motor for $300, swap core plugs, head gaskets, etc.and go boating