Cracked Engine Block Question?

1

1fishbone

Chief Petty Officer
Joined
Nov 9, 2010
Messages
476
Re: Cracked Engine Block Question?

WOW...never heard of an engine crack with no indication.

From what I read, you used it, serviced it and now it's cracked?
If you had a cracked block you would know it!

It takes a REAL hard freeze to crack a block.
There are freeze plugs, hoses could slip or crack first.

I suspect a 'snow job'.

How much do you trust this mechanic?
 
Bondo

Bondo

Moderator
Staff member
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Apr 17, 2002
Messages
70,525
Re: Cracked Engine Block Question?

Ayuh,... Welcome Aboard,...

#1,... It'll probably last for Years,...
As long as you've run it, it ain't dropped water into the oil, Right,..??
It's an external, Not internal crack.... Butter it up with epoxy, 'n Enjoy the boat...

#2,... Ya can't rebuild it, it's a Cracked Block... Run 'er til she Pukes,...
Then replace it with a Long Block....

#3,... Fresh motors can be found for about $1500., 'n Up....
 
B

buzzm19

Petty Officer 2nd Class
Joined
Dec 14, 2009
Messages
152
Re: Cracked Engine Block Question?

If I were you as stated get a couple opinions, I am an mechanic and if the block is cracked on both sides you would have to see water in the hull especially when its running. I would guess that your freeze plugs or maybe a head gasket and a crack in the block highly unlikely and then again both sides? Just my opinion Buz
 
redjmp

redjmp

Chief Petty Officer
Joined
Mar 16, 2005
Messages
536
Re: Cracked Engine Block Question?

Just because it is cracked doesn't mean its all bad. Like Bondo said, the cracks are external and the motor ran great! It would not necessarily leak if they were just hairline cracks that got filled in with rust.

If this is a raw water block, the cooling system is under very low pressure and would not leak much if at all.

Get a wire wheel and clean the area around the cracks well and then use some JB Weld to seal it up well and be done with it.

I had a friend back in high school who had a 427 in a Vega that he used to take down to SIR and race when he blew a rod out the side of the block at 160 mph. Resleeved that hole and patched it with JB Weld and it ran fine for years more.

I used it on an old Cornbinder DT 466 I had cracked a coolant elbow clean off and it held up great and was running strong 6 years later when I sold it.

Now there's a great motor that should have been marinized.
 
redjmp

redjmp

Chief Petty Officer
Joined
Mar 16, 2005
Messages
536
Re: Cracked Engine Block Question?

buzzm19 said:
... your freeze plugs
Click to expand...

That's a misnomer.

They really aren't "freeze" or "frost plugs" at all.

Sometimes they do pop out but really they were not designed to do so.

Those holes are a result of the casting process and of course they are plugged but they won't prevent your block from cracking at all when it freezes.

A lot of times they wont pop at all and even if they do, chances are slim that they saved your block...
 
W

wallerus

Seaman Apprentice
Joined
Jan 8, 2010
Messages
32
Re: Cracked Engine Block Question?

The repeated loading and unloading of the block will eventually cause these areas to fail. Best case, a small chunk comes out. Worst case catastophic engine failure leaving you stranded, large chunk comes out fills bilge with water and you get a nice swim or a ride with the coast gaurd.

I have used Marine tec in the past and it has worked to keep the leaks out until failure. unless you replace the short block I would make sure I had a really good bilge pump.
 
A

Aloysius

Chief Petty Officer
Joined
Aug 21, 2010
Messages
484
Re: Cracked Engine Block Question?

redjmp said:
That's a misnomer.

They really aren't "freeze" or "frost plugs" at all.

Sometimes they do pop out but really they were not designed to do so.

Those holes are a result of the casting process and of course they are plugged but they won't prevent your block from cracking at all when it freezes.

A lot of times they wont pop at all and even if they do, chances are slim that they saved your block...
Click to expand...

Thank you!! A major misconception.
 
N

netting one

Petty Officer 2nd Class
Joined
Mar 23, 2010
Messages
112
Re: Cracked Engine Block Question?

First did you see the cracks? You can have 3 kinds of cracks,internal,external or both. Internal is a tuff,tuff one to find and fix (new engine) both give it up also, external can be repaired. It does have low pressure so wire brush the area clean it with thinner,make sure its a little warm and epoxy it! done deal.
 
J

jay1929

Cadet
Joined
Oct 31, 2010
Messages
9
Re: Cracked Engine Block Question?

Not sure if you saw my post a few weeks back, but the same thing happened to me. My mechanic is replacing the block with a reman, replacing one exhaust manifold, water pump, impeller and winterizing for about $4,000 (parts & labor). I hate to spend even a dollar because this boat is an 08. The seller is a low-life that tricked me. But, I have learned my lesson (the hard way). The remanufactured block is saving me about $800-$1000. He assured me it wouldn't make a difference, same warranty too.

Mine is not leaking water in the oil either, however it sure is expoyed up! I just don't want to take a chance in the summer and then be out of commission so I'm getting it done now.

Good luck!
 
redjmp

redjmp

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Joined
Mar 16, 2005
Messages
536
Re: Cracked Engine Block Question?

jay1929 said:
Not sure if you saw my post a few weeks back, but the same thing happened to me. My mechanic is replacing the block with a reman, replacing one exhaust manifold, water pump, impeller and winterizing for about $4,000 (parts & labor). I hate to spend even a dollar because this boat is an 08. The seller is a low-life that tricked me. But, I have learned my lesson (the hard way). The remanufactured block is saving me about $800-$1000. He assured me it wouldn't make a difference, same warranty too.

Mine is not leaking water in the oil either, however it sure is expoyed up! I just don't want to take a chance in the summer and then be out of commission so I'm getting it done now.

Good luck!
Click to expand...

Wow I'm not sure who the bigger crook is here the guy who sold the boat or the guy who scared you enough to soak you $4k for a needless repair imho.
A new reman short block can be had for about $1100.
But if its not leaking into the oil, then it would be fine.
There is not much strength in the water jacket anyways and the block certainly would hold up even if the jacket had a crack.
But its your cash and if it makes you sleep better....
 
P

paw2000

Petty Officer 2nd Class
Joined
Jul 9, 2009
Messages
106
Re: Cracked Engine Block Question?

Labor is the killer on that repair, shop time is big $$$, The boat is not old so its worth it. So when its done and out next year on the water all is forgotten.

I just bought 2 complete inboard bobtail motors, cost was $10,500 for the pair (1 counter-rotation) My original motors weren't worth saving, I sold the 1 running engine and trying to give away the seized motor. To me it was worth the cost for peace of mind.
link to motor startup http://s765.photobucket.com/albums/...ction=view&current=newinboardfirststartup.mp4

To the cracked block situation, run it til it fails, the motor seems to be running fine. Since you know its problems you can be prepared for the inevitable. Maybe you will goto a 383 stroker motor in the future, or come across a great deal on a long block, at least you have options
 
J

jay1929

Cadet
Joined
Oct 31, 2010
Messages
9
Re: Cracked Engine Block Question?

redjmp- I appreciate your opinion. The mechanic actually suggested I run it till it cracked even more. He said just to keep good check on the engine compartment to make sure it's not full of water. How long do you think the epoxy would last. My mechanic said it would last anywhere from three minutes to three plus years. The manifold is cracked and leaking, so it needs changing anyway. Most remans I've seen cost around 2k (some are cheaper, some are more). Manifold is about $200-$300. And labor isn't free. I definitely don't want to spend the money, but don't want to be stuck out in the middle of the lake either. Again, I appreciate your thoughts and input.
 
Bondo

Bondo

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Staff member
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Messages
70,525
Re: Cracked Engine Block Question?

My mechanic said it would last anywhere from three minutes to three plus years.
Click to expand...

Ayuh,... I'll venture 3 minutes to 30 Years....;)
 
proshadetree

proshadetree

Lieutenant Commander
Joined
Jul 19, 2008
Messages
1,887
Re: Cracked Engine Block Question?

I have a 68 ford with Jb welded radiator for 25 years. We use it for small holes in radiators all the time on forklifts if we have a cheap customer that will not foot the pull and repair/replace bill. I have welded manifolds on my baylinner 2 years no problems. Cracks stink but not the end of the world.
 
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