I need help with a cracked engine block problem

Hello All,

I need advice with an engine block crack. I have a 1986 Searay with a Mercruiser 5.0 I/O motor. I took it in to get ready for the Spring/ Summer season and found out that the engine block had a crack in it. It was recommended that I spend $6000 on a new motor. That wasn't working for me because I paid less than that for the boat less than a year ago. The boat mechanic told me that some people have welded cracked engine blocks and they have worked for many years. It took me a while to find a welder that would or could weld it. Because it was in a tricky spot under the right side of the engine the welder was able to weld the crack but said that there were a couple pin holes that he couldn't get to. What do I do now. The boat mechanic doesn't seem to either know what to do next or isn't motivated to do anything with it. I am very limited when it comes to mechanics. I'm good at building a fixing things in a home but my knowledge with engines is very little. I've replaced batteries, air filters, belts and alternators in trucks that I've owned but that's about it. Please help?

Re: I need help with a cracked engine block problem

Since I don't know how much you paid to have that crack welded, I can't say that you are throwing good money after bad...but I would have simply recommended you pick up a used 350 and have it rebuilt. Will fall right into place where the 5.0 sat. No other changes necessary for the boat given the year of manufacture.

Get yourself a post '86 roller provisioned block and throw a set of Vortec heads on it with a roller cam and lifters. Good for 300 stock hp.

Re: I need help with a cracked engine block problem

Ford 5.0? You may want to consider a junkyard truck engine/shortblock. 302's are plentiful and cheap.

Re: I need help with a cracked engine block problem

Radarman68 said:

Ford 5.0? You may want to consider a junkyard truck engine/shortblock. 302's are plentiful and cheap.

Click to expand...

Not in '86! It's a Chevy.

Re: I need help with a cracked engine block problem

Thanks Silly Seville. It's a Chevy motor. Does anyone have any ideas other than a new engine. I can't do the work because I don't have the first clue. It's like someone deciding to do a construction project without the right tools to even start.... That's what I'm good at. As it is, I bought this boat last year to do something cool with my three kids. Can I fix this motor so that it can be used this summer? Does anyone know anyone that can help me without charging me $6k?

Re: I need help with a cracked engine block problem

PM sent.

Anything can be "fixed". That doesn't mean it should be. It's false economy to think that a simple patch or "band-aid" repair will get you through summer. And since I don't know where you plan on boating...I can only suggest that you do not put your kids in harms way by taking chances out on the water with a questionable engine.

Update your profile and you will get far more helpful responses. We need to know exactly which boat you have and what waters you will be using it on. Also, your level of experience as a captain is relevant.

Re: I need help with a cracked engine block problem

sorry to hear you started your boating that way. the hard thruth might be you have absolute no options. when the block freeze cracked it probably will have also cracks to the inside you have no chance to weld or even see them. further your manifolds might be also shot.

what i would do - treat any visible crack with liquid metal when you can get into this place and just run the engine. when it runs bad and you get milky oil ( water in oil ) you are really done and have no options. do no invest any further money on that engine .

and be aware that when the weld "opens" underway you will start to flood your boat , might be without immediate notice of that and depending where you are boating things may start to go really bad with your kids onboard.

look for used 5.0 and try to get contacts in your local marina. there might be guys who have the knowledge and willingness to change you the engine for little money or even some good beers and barbecue.

last idea is to sell the boat as it is trying to get the best out of it .

wish you luck !

Re: I need help with a cracked engine block problem

BLevens-

Welcome to iBoats. . . As you have stated, you are not adept at hard-core engine rebuilding, etc. So, you will have to rely on others (mechanics, machine shops, etc) to solve your problem. The help you need is money, sorry to say.

Some folks have outlined approaches to replacing the engine block, etc, but unless you can do that yourself and thereby hold the costs down, then it all relates back to money.

The $6K figure that you were quoted is a fair amount of money, and perhaps you can shop that around and get a better price, but that is an expensive road to travel. You might be able to have another shop take a run at the welding, or perhaps just go with some "JB Weld" (industrial epoxy) to seal things up.

The thing that you do not know is if the engine has any internal cracking, and will have issues, regardless of the external fix. You could pressure test the cooling system to get an idea if your current repair approach is even worth it.

Re: I need help with a cracked engine block problem

yes hiya id def.. do a pressure, leak down test they are fairly simple to give u a idea of internal damage before u do anything else then go from there ....

Re: I need help with a cracked engine block problem

I would try the JB Weld route suggested by tpenfield if you can access the location of the crack. Clean up the spot with a dremel tool first to improve adhesion. Try it on the muffs first and if that passes try it on the lake. Take a cell phone with you and I wouldn't go to far from shore. This is not a permanent fix but it may get you though a summer of two. If it doesn't work, you're only out the cost of JB Weld and your back to where you are at now...

Re: I need help with a cracked engine block problem

Don't let anyone try to weld your block any more. Welding cast iron needs high temps that you can't get for a good weld. So you will need to go over the repair with epoxy any way. If it's a water jacket leak all you need is to hold 15 or 20 psi. You can fix it with JB Weld, or there is another product called Marine Tex that you might want to use. Whatever you use, once you have repaired the visible crack you will want to then pressure test the cooling system. If it has internal leaks the most common place those occur is below the intake manifold inside the V of the engine block.
Accessing that requires removing the carburetor, distributor, and intake manifold.
The boatyard wants to replace the motor because they can't stand behind a repair like that. Plus it pays well. Lousy situation.
Question, did this same yard winterize your motor, and do they guarantee their work?

Re: I need help with a cracked engine block problem

1blevens1 said:

Hello All,

I need advice with an engine block crack. I have a 1986 Searay with a Mercruiser 5.0 I/O motor. I took it in to get ready for the Spring/ Summer season and found out that the engine block had a crack in it. It was recommended that I spend $6000 on a new motor. That wasn't working for me because I paid less than that for the boat less than a year ago. The boat mechanic told me that some people have welded cracked engine blocks and they have worked for many years. It took me a while to find a welder that would or could weld it. Because it was in a tricky spot under the right side of the engine the welder was able to weld the crack but said that there were a couple pin holes that he couldn't get to. What do I do now. The boat mechanic doesn't seem to either know what to do next or isn't motivated to do anything with it. I am very limited when it comes to mechanics. I'm good at building a fixing things in a home but my knowledge with engines is very little. I've replaced batteries, air filters, belts and alternators in trucks that I've owned but that's about it. Please help?

Click to expand...

Ayuh,.... Welcome Aboard,.... I'm with NHguy,... Who winterized the boat,..??

If it's crack, Only Externally, 'n Not dumpin' water into the oil,...
forget about havin' it welded, Epoxy it, 'n Run it...