Water Jacket Repair

[Milkman38]

1st off... NOT MY BOAT!! Its my friends but I seem to have inherited his issues.
1987 3.0l Mercruiser that was not winterized properly. There is a horizontal crack in the water jacket. Aside from that I am struggling to get it running. I have checked compression (all good) but what I am wondering is if/when I get it running is JB Weld my only option to seal the crack? Assuming no water shows up in the oil and its just the water jacket can it be welded? If so... whats the best technique for cast iron?
Is there anything else to watch for when it does run?

 

[Bondo]

Ayuh,.... Welcome Aboard,.... JB weld, or plain ole epoxy resin, 'n glass can be used to seal up the outside,....

Weldin' don't work, ya gotta epoxy over it because of all the cracks the weldin' causes,....

If it's cracked inside, into the oil,....
Ya need another motor,....

 

[Bt Doctur]

If the crack is only EXTERNAL it can be repaired with JB or Plumbers Epoxy.
V grove the crack and drill stop holes at each end. Clean throughly and I mean THROUGHLY with acetone and steel brush.
Apply pushing it into the cracks , let cure and file /grind to finish.Apply a second layer and let cure 24 hours.

 

[Dave-R]

I have done the Same J-B weld fix on a 4.3 V-6. I did exactly as B.T. Doctor said. I did take the engine out, and put it on a stand to work on it. That was 6 years ago and not a drop of leak yet. Dave-R

 

[tpenfield]

Not sure how you would check for INTERNAL cracks in the block, other than a cooling system pressure test, but if there is an external crack, who's to say there are not any internal cracks. :noidea:

 

[Milkman38]

I am unable to get the thing running to check all the rest of it. Done everything I can. Acts like the timing is off... way off. Thanks for the tips. Should it get to that remains to be seen.