Cracked Water Jacket Fix?

[huntxtrm]

I am new to this side, usually on outbourd forum. Here's my problem. I have a newlly aquired 1978 webcraft about 22ft I think, 250 hp mercruiser i/o. V8 looks like 350 chevy to me. I am in the process of rebuilding this boat. After removing all the cowling, I found someone, aint gonna mention no names(Dad I think) did not drain the block for winter. There are cracks on both sides of the block just below the heads, about in the middle of the block length ways. About where a middle freeze plug would normaly be. The cracks are about 4 inches long. There is no water in the oil. I think only the water jacket is cracked. he says he think he ran it like this for a while, because water kept gettin into the boat, he could not figure out from where. I think I figured it out. Any way I am thinkin about getting them welded, anybody know if this will work? Any better alternatives, that dont involve spending my life savings? Sorry for the long post, just trying to give all the details. Thanks

 

[Don S]

Re: Cracked Water Jacket Fix?

Just because there is no water in the oil right now, means nothing if you haven't run it. Those "freeze plugs" aren't and don't prevent damage when the block freezes. Read this thread http://forums.iboats.com/showthread.php?t=192525

I would bet your engine is bad inside as well as out. Pull the intake and look for cracks in the area above the lifters before you do a lot of external crack repairs of any kind.

 

[huntxtrm]

Re: Cracked Water Jacket Fix?

From what pops was saying, he has been running it. By the looks of the cracks, they are not fresh. There is rust build up streaming from them going down the block. They appear to have been that way for some time, with no apparent engine trouble. Would a compression check confirm a crack in the combustion chamber? These engines are low pressure cooling arent they? So would cylinder pressure leak to the water jacket? Or if water is getting into the combustion chamber, would I be able to id this by spark plug condition, appearance? Sorry for all the questions, my first I/O.

 

[Don S]

Re: Cracked Water Jacket Fix?

The crack would have nothing to do with the compression, it would be in the cooling passages. With visible cracks on the outside, it's just a mater of time. You can't pressure check the cooling system because of the external cracks.
But cheer up, miracles do happen and you may be ok. There just isn't any way to find out other than running it.

 

[launboy]

Re: Cracked Water Jacket Fix?

You might want to try using some JB Weld on those cracks. I'm not sure how long/well it will hold, but I've heard of others using this method to repair cracks.

HTH,
Adam

 

[Bondo]

Re: Cracked Water Jacket Fix?

Any way I am thinkin about getting them welded, anybody know if this will work? Any better alternatives,

Ayuh,..... Welding is Not really an option.....You'd have to strip it to a Bare Block 1st....

If by some freak Chance it isn't Cracked on the Inside,....
Epoxy the cracks in the Outside,+ Run It....
If it's cracked Inside,..... You'll know soon enough.....

The Only Reliable Repair is to Replace the motor.....

 

[huntxtrm]

Re: Cracked Water Jacket Fix?

I hope it's the easy fix. Why would you have to strip to a bare block to weld? there is plenty of working room around it. I am hoping to fix it for as little as possible, I've already prepared my children for the worst, explained about the importance of boats, xmas, how they already have more stuff than they will ever play with, that sort of thing.

 

[Bondo]

Re: Cracked Water Jacket Fix?

Why would you have to strip to a bare block to weld?

Ayuh,....

If you can't Preheat,+ Postheat it,... It'll crack More just from the welding process...
And,....
The Best, Easiest way to preheat,+ postheat is in an Oven......

That's Why I keep saying that Epoxy is a Better alternative......

I am hoping to fix it for as little as possible

Then go buy a 350 Take-Out motor from a Truck, at a Junkyard,+ Swap it into your boat......

 

[tommays]

Re: Cracked Water Jacket Fix?

I dont know that many people brave enough to weld inside a gas powered hull while there sitting 18 inches from the fuel tank

 

[SS MAYFLOAT]

Re: Cracked Water Jacket Fix?

This sounds as if the "Lacing" method would work well for your cracks. A Drill, a tap, and some pipe plugs. Some people don't rely or won't trust this method, but it works, is cheap, and if done right it won't leak a drop. I've done several boat engines and truck engines. None that have failed, It is the poor boys method of fixing when there is a tight budget. If interested, I can PM you on how it is done.

This method is also called metal stitching. I found this site which can explain better

patentstorm.us/patents/4845828-description.html

 

[huntxtrm]

Re: Cracked Water Jacket Fix?

Metal stitchin sound interesting, send me the info if you don't mind. As far as welding next to the gas tank, this is a resto poject, the boat is completely stripped. Just motor, outdrive and hull. It's an old boat, 1978, just don't want to spend a heap on it. Do want it to be dependable. Thanks for the info, keep it coming.

 

[huntxtrm]

Re: Cracked Water Jacket Fix?

I wonder, since it is flat portion of the block. Could I just drill holes at the end of the crack, to stop further cracking. Drill and tap 4 or more holes around the perimiter of the crack. Fashion a plate and seal, attach it to the block mechanically with screws. Recon it would work? That is if the metal stitchin isn't feasable.

 

[whywhyzed]

Re: Cracked Water Jacket Fix?

......?

 

[SS MAYFLOAT]

Re: Cracked Water Jacket Fix?

Check your PM

 

[Bondo]

Re: Cracked Water Jacket Fix?

I'd just slap JB on it - yeah drill the ends of the crack 1/8" or so. Doing anything else to a block that has a replacement cost of approx. $75 is rediculous. If you're gonna put more than 1 hour labour in the job - go grab another block. Either slap-patch it with a prayer, or fix it right.....

Ayuh,...... I Totally Agree,...... 100%...........

 

[huntxtrm]

Re: Cracked Water Jacket Fix?

I don't mind the fuel, just aint wanting to spend over 1000.00 or so on the engine. Runnning around on the lake is fun, intalling a new engine isn't as fun. but if a cheaper alternative will work, why not keep my 1000.00 instead of giving it to someone else. I like to save when I can.