SB Chevy with Cracked Block

[Steve Braverman]

As if I don't have enough problems, I have a boat. It has a Volvo-Penta stern drive with a Chevy 350. The engine was not properly winterized, and the block cracked just below the head gaskets on both sides. The cracks are very minute, and are only visible because of the staining from leaking water. Can this be fixed, or is the engine junk? The engine is fairly new.

A professional mechanic friend said it can be fixed with marine tex or JB weld, but it's a questionable repair.

[TomTIII]

Add to the list of "magic potions" Belzona... the closest thing to a real weld... look for the high heat material. Pre-heating the completely disassembled block, micro-drilli ng the cracks if they end in solid matrix, and welding can fix this, but it's not a 1914 Isotta... probably cheaper to look around for another block or engine if the epoxy compounds don't work. I had a cracked VW block that lasted about two years with epoxy fix. But with a boat, you don't want it to fail somewhere where Towboat US charges as much as the new engine.

Good luck,

Tom

[joe_padavano]

I'll second that. If the cracks are only in the water jacket, you can probably have them welded. Of course, will you be certain that you have them all? SBC blocks are cheap and plentiful.

[Guest mercman86]

Chances are, it has internal cracks and a cracked intake. I am in the marine business and have seen this many many times. We try and weld em and they just spew milky oil out the carb and then blow up. If you are able to seal the crack on the outside, run it and keep checking the oil. If it turns white or "makes oil" by raising on the dipstick, its cracked internally. Pull the intake and you will see cracks on the bottom of the intake manifold, cracks on the sides of the valley and cracks on the heads. When they crack, they crack. The only engines that seem to survive freezing are the inline 6's and 4's. But ive seen only 1 out of 10 "V" engines survive a hard freeze.

Good luck with it!