SC65 needs some input

[starcrafter65]

Brethren - asked this on the motor section but it quickly disappeared.

The original motor was smoked so I picked up a 1989 MC 3.0l 130 HP motor. Kind of a weird story...PO buys used boat from dealer and uses for 3 years....then notices water dripping....looks under manifold and sees jacket had crack from freezing that was fixed. Motor runs great and has 150 compression on all 4 - anyway PO owner goes back to dealer (who had never told him about the crack) and complains. Some deal is struck PO ends up with rebuilt motor in boat and old motor in garage. The PO was pretty detailed and I am sure the thought of having a "fixed" motor just wouldn't sit.

Anyway - I am sure you have all seen it....what are the best options/products to garage fix it myself?

 

[starcrafter65]

Re: SC65 needs some input

I can see you guys are looking at this!!!

Nobody froze their engine?

I figuere it out and tell you how it worked!

 

[Bwana Don]

Re: SC65 needs some input

Nope never froze my engine. I would get another block and transfer the guts over. IMHO

There is a mercruiser forum here. The real pros hang out there, we're just a bunch amateurs compared to them. Seriously there are some real crackerjack mechanics that can give you the advice you need.

As far as I'm concerned once a block is cracked it's near impossible to repair. I'm no pro though, so get another opinion please.

Good luck, I hope it turns out good for you.

 

[starcrafter65]

Re: SC65 needs some input

I tried the motor portion....my thread fell off the front page faster than fast!

 

[North Beach]

Re: SC65 needs some input

Clark, have you explored the jasper short block option?

Posting all the same disclaimers as above

Edit***** did you say it was repaired and runs just fine?

 

[starcrafter65]

Re: SC65 needs some input

Clark, have you explored the jasper short block option?

Posting all the same disclaimers as above

Edit***** did you say it was repaired and runs just fine?

My main concern is that when I install the Nox and the Blower the crack might get bigger!!!

Yes - it ran fine - and ran fine for 3 years - visiting the PO - his boat, motorcycle etc were all perfect - so he was a perfectionist. The motor ran with a drip, compression on all 4 was 150 and there was no water in the oil - just a small exterior crack below the exhaust manifold. The PO gave me some high temp epoxy - or I could take it to a motor repair shop and have them cold weld it. Welding is out as the heat warps the block.

Just wondering if anyone had done something similar....I mean the NOx and blower of course!

 

[Bwana Don]

Re: SC65 needs some input

I'm thinking 4 weber carbs might do you better. Nitrous kills a motor sooner or later.

There is probably an epoxy, high temperature that will work. I just read about it in my truck or hotrod forum. I think it was on the truck one, Rangerstation.com I think. I'll find it but it will take a little time. I belong to hotrodders.com I'll nose around there.

Could someone bump his thread in the mercruiser forum?

I still think a bare block is the way to go, my .02 cents.

edit:
www.Therangerstation.com

 

[Bwana Don]

Re: SC65 needs some input

I'm finding quite a few people recommend JB Weld. If you go on their web site they even say it will fix engine blocks and cylinder heads.

http://jbweld.net/products/index.php

 

[elkhunter338]

Re: SC65 needs some input

I am no expert. An electrical engineer who grew up with a dad and grandpa as automotive/diesel mechanics. I have heard you can weld blocks with mixed success. My dad slathered some jb weld on a cracked toyota block and it just weeped. Access was a problem without pulling the motor.
If you are fresh water cooled I might just let it leak.
I might consider drilling both ends of the crack so it does not grow, drill tap it for a bolt (like #10 machine bolt). Install a bolt with thread sealer, then grind out the crack just alittle and put jb weld in it with some fiberglass mesh and more jb weld. See what happens. Most metal cracks will grow unless you drill a hole at the end of the crack to stop the crack. Might also consider installing a sealed stainless pot rivit with jb weld.
I would search for a better product than jb weld if one exists. With fresh water cooling I believe you have no pressure in the water jackets so this will be a help.
Another idea would be to drill tap both ends of the crack and bolt a small steel plate over the crack with lots of high temp sealer and let cure. The sealer will allow some contraction to take place without breaking the water tight seal between the block and steel plate. I would try and find an old block or manifold and try drilling and taping for a trial run.
These are just my thoughts. I have never done what I am recommending on an engine block.
I would do some internet searching on recommendation on how to repair cracked engine blocks, this type of issue is not just isolated to the boat world.

 

[starcrafter65]

Re: SC65 needs some input

Whelp......I pulled the trigger on JB last night...the hight temp epoxies are basically all the same recipe (Marine Tex....etc). It is not under stress so as long as it has a good bond - should work. I hit it with a cup brush/grinder + acetone before applying - ot was literally 2 pin holes.

Of course I will post pictures and outcome in my resto thread! I am going to test of course before going out!

 

[Bwana Don]

Re: SC65 needs some input

I think that was a very good move. I couldn't find anything better, and I did find many positive testimonials. 2 pin holes, you should be golden.

Let us know how it works.