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Cracked 305 block


Lew

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I have a 2001 5.0L (305) block that is cracked on both sides of the block and their c shaped, the previous owner never took out the block plugs. The other 3 were removed. The engine only has 104 hrs on it and it has no water in the oil so the internals are fine. It runs fine but leaks water out the cracks. Any suggestions on this would help, Anyone got a stock bore block? If so I could switch over the rotating assembly, with new bearings and rings of course.

Thanks

Lew56

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Lew56, I had the same problem when i bought my boat 10 years ago . I sealed it with a block epoxy and it is still holding good, I know that you can get it from Boat US and is around $40.00

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JR I had the suggestion of using JB Weld, But I'm not sure if it would stay and not come off out in the middle of the big pond. :( Is the black epoxy the same as JB Weld? And Jeb I have heard of pinning before, anyone around here do it? I thought about welding it with cast rod, I have welded and brazed cast many times before at work, just not a engine block. Has anyone else repaired blocks before and had success? Not sure what way to go, Long blocks are like 1500.00 bucks, and I just bought the boat and the better half is still not over it!! I need a :beer:

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Lew56, No JB weld is not the same as the epoxy, the epoxy is made for sealing cracks in blocks and Manifolds and i don't remember the Name but if you ask them they should have someone there to show you which one to use .

if you go with the epoxy make sure to clean the block good and rough it up with a die grinder or something to give it a good bond .

Which ever way you decide to go keep us posted on how you made out .

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I have epoxied a block and it worked great. First you want to drill a small hole at each end of the crack to keep it from spreading . Then grind the crack to get a good clean surface . I even drilled a few 1/8" holes along the center of the crack to force the epoxy into crack to give it more holding power. ( you want to force the epoxy into the crack so it curls into block )

Boat engines don't build up pressure like the closed cooling system in you car. Unless the crack is so bad that the whole piece could fall off I don't think you have much to lose by trying the epoxy.

Good Luck JT

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Thanks for the tips! I'm going to stop at West Marina in H2OTown today and see if they have any of that black epoxy, If they have been repaired with success maybe I'll give it a shot and hold off on finding a block. I know they have a welding rod now that doesn't require preheating and the cast I welded years ago we always had to preheat and slowly weld and peen it. Hummm now you guys have my ole mind thinking here and yes I could save some $$$ make the wife Happy!! Cool!! :yes:

Thanks

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The black epoxy in question is called Marine-Tex and yes, depending on the location and prep work as Jack stated above it can & does work out well in some situations as long as you are sure you only have an external leak. Make sure this time of year especially to adhere by the recommended temperature usage in the instructions. The warmer the ambient temp. the better the bonding.

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Ok I picked up the Marine-Tex yesterday, now to remove the engine. Any tips on this would be cool 8) I have removed and rebuilt a few Chevy's from cars just not from a boat. It looks like it could be a interesting adventure!

Thanks Again

Lew

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I cleaned up the cracks and the area around the crack with a die grinder, drilled the holes in the cracks cleaned it all up with cleaner and laid on about 1/8" of the Marine-Tex. Will that be enough 1/8"? or should I add more on top of the 1/8"?

Thanks

Lew

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Update

Well I let the Marine-Tex setup good and gave it a paint job, my son and I yesterday got it all back together. Hooked up the water muffs and started it up. And no leaks we run it for awhile up to temp no leaks!! Also wanted to run the Sta-Bil though the system. I pulled all 5 blue plugs and drained the water out, now what else should I do to winterize it? Add anti-freeze to engine or should it be ok just draining at the blue plugs? Thanks for the tips on repairing the block!! :yes:

Lew

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One good thing to remember . If the crack isn't so big that the part will fall out there is plenty of water in the lake to refill the block until you get back to shore. Make sure your bilge pump is in good shape and carry a five gallon bucket in the boat just for a back up . Good luck

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The previous owner ran it with the cracked block leaking, he just installed a larger bilge pump to remove the leaking water. If the Marine-Tex is as good as they say it is I should have no problem. L&M I took your advice and ran some RV antifreeze though it, I even added some to the bilge pump Thanks for the tip :yes:

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