cracked engine

[wagner]

This is my first time on this forum and I need some advice/opinions.

I have a 1989 Mark Twain, cobra inboard motor, i just put it in the water this weekend and there was water coming from the engine. There is no water in the oil.

I put it in the shop and they told me that there is a small crack and they could fix it for approx. $350.00 but that i really didn't have to fix it and that it won't get any bigger if i get it winterized properly from now on.

My questions are: could that be true that the crack won't get any bigger?
and will the engine be okay with all that water running over it all the time?

Any advice would be great.

Wagner

[boatn]

The last time I check is that when the engine block is cracked its cracked and it needs to be replaced Technolgy must be better if they can fix the crack!

[jehardiman]

First...where is the crack?

If the boat was allowed to freeze with water in the block then the water expanded and cracked the block or knocked out a freeze plug. If the crack was on the outer face of the block, then water from the water jacket would just leak out into the boat ( Whats the difference between a leak and a flooding casuality?...Wether you fear for you life...) Cheap quick fix is to drill the crack ends and soulder it up or replace the freeze plug ( both sound like $350.00) but you may have to strip the engine. RTV could stop the leak without removing the engine, but the crack could grow. It is unlikely that, for most motors, a crack in the outer water jacket would continue to grow.

The real question though, is if there is any internal damage from the freezing. It could have made a cylinder out-of-round or warped the block. That can't be answered unless the motor is taken all the way down and mic'ed. At that point, the block can be permanently repaired by furnace welding.

[Mayfly]

depend where the crack is and gouging and welding does the work temporarly. Permant fix will be buying a new engine.

[wagner]

Jehardiman, you are correct, the repair guy said around $350.00, it is on the outer part of the engine, everything is running fine. I ran it on and off for approx. 9 hours in one day and only had to use the pump 2 times and could have gotten by with using only once. I was told by 4 other boat repair shops that it will be okay, but i think I will get it fixed because of the thought of what could happen, and afraid of forgetting to turn the pump on.

Thanks for all of your inputs, gave me lots to think about and more questions to ask the repair guy.

Thanks.

[tmn114]

Hi guy, I have a very similar problem with the above post of engine crack. I have a Mercruiser 5.0L V8 on a 2001 Glastron GX 205 fish and ski which I only pay less than 7k for it. The engine looks brand new and is runing fine and there is a visible crack on the side bottom where the cooling water is leaking out. Someone suggested me to get a welding job on it. My question is do the welding job really work? Or do I have to get a new block for it? Being a female knowing nothing about boat and though that I have had a good deal on it. Do you think this is a good deal or it would ended up a bad deal if I have to spend a lot on it?

I would be very appriciated you feed back to tmn114@yahoo.com. Thanks ya all.

[george allard]

We repair external cracks often. If it is not that long, drill a 1/8" hole at each end, grind of any paint 2" wide around the crack, and apply a material called J-B Weld. Any NAPA auto parts store has it. 9 times out of 10, it will last forever. The repair will cost you about $10 and one hour of time.

[tmn114]

Thanks for your reply! here is a little bit more about my case. The crack is a round crack of 2" in diameter and it looks like the metal is being push out from the inside. It is on the right side of the engine right above the oil pan. I have done a bit of research on the "Metal Stiching" method and it is sounded very interesting. Do you know of any good store that I could order these kit and do it myself? Thanks very much.

[stonebreaker]

Originally Posted by tmn114

Thanks for your reply! here is a little bit more about my case. The crack is a round crack of 2" in diameter and it looks like the metal is being push out from the inside. It is on the right side of the engine right above the oil pan. I have done a bit of research on the "Metal Stiching" method and it is sounded very interesting. Do you know of any good store that I could order these kit and do it myself? Thanks very much.

A round crack? Is it an actual crack with jagged edges? There are 2-3 freeze plugs on each side of the engine that are designed to pop out when any water in the block freezes, in order to limit damage to the engine. Could it possibly be one of these plugs that popped out? The location sounds right.

[tmn114]

Actually it is not a round crack but rather more like an oval shape and I don't think it is the freeze plug at all. I actually order a kit from metal stiching company down in CA (http://locknstitch.com). Because the oval piece fall out broke in half that it is harder to do the metal stiching because every time I put a srew in one piece it knock the other out of place. What I did was using a couple of screws to keep the two pieces in place and then using JB Weld compound to clue all and put a thick layer of this compound over the top. It seems to hold up very well, but now I found another smaller crack on the other side at the same place, so now I have some more work to do. I hope that the JB Weld compound would hole up.

My other question is that does it has any pressure when the engine is runing to push the wall out again? How hot is the water and the engine wall where the crack is?

Thanks,

[stonebreaker]

Well, it was a thought. Good luck with your repair. I'm a big fan of JB Weld, myself. It works great but the metal has to be absolutely clean and dry when you apply it. It cleans up with alcohol as long as it's still wet.