Cracked block

[Buck0317]

I have a 3" crack in my 3.0 mercruiser engine. I've read using JB Weld will work. I need to drill holes at the end of the crack. How deep do I need to drill the holes?

 

[crazy charlie]

Good luck with that!! If you are drilling holes ,the reason is so the crack does not continue further.Reason for the crack is probably freezing water inside the block or severe overheating.If you dont plan on either of these happening again then I would pass on the drilling.If you choose to drill then drill the same depth as the crack.I would dremmel the crack to get a fresh surface for the JB to stick to and so there is more JB filling the gap.DONT use the quick cure type as it does not work as well.JB takes a while to cure and will sag and drip before it cures.Plan on putting a piece of quality duct tape over the repair to stop sagging of the JB while curing.I would also recommend slightly more hardener than 50/50 mix and dont apply it right away.Let it begin to harden ,it will get more like a peanut butter consistency and will apply better.Post results.Marine Tex is also a good choice.Charlie

 

[racerone]

What are the chances of cranks in the block that you can not see at this time.

 

[ahicks]

There are thousands of people that go many years without rusting out a set of bearings or even seeing a drop of water.

I would suggest you find out exactly why yours is leaking.

 

[Buck0317]

Good luck with that!! If you are drilling holes ,the reason is so the crack does not continue further.Reason for the crack is probably freezing water inside the block or severe overheating.If you dont plan on either of these happening again then I would pass on the drilling.If you choose to drill then drill the same depth as the crack.I would dremmel the crack to get a fresh surface for the JB to stick to and so there is more JB filling the gap.DONT use the quick cure type as it does not work as well.JB takes a while to cure and will sag and drip before it cures.Plan on putting a piece of quality duct tape over the repair to stop sagging of the JB while curing.I would also recommend slightly more hardener than 50/50 mix and dont apply it right away.Let it begin to harden ,it will get more like a peanut butter consistency and will apply better.Post results.Marine Tex is also a good choice.Charlie

 

[Buck0317]

Thanks Charlie!