Cracked block.....now what?

[temperedtim]

Re: Cracked block.....now what?

I like boattechs method. If it's really flared out then I'll use his idea to slowely hammer the crack closed a bit. It's it not that big and not super rusty I'll clean it up....v it out and jb weld it. Do I have to take off the carb and exhaust elbow or can I leave those on the manifold and remove it all as a unit and save on gaskets?

 

[marlboro180]

Re: Cracked block.....now what?

I like boattechs method. If it's really flared out then I'll use his idea to slowely hammer the crack closed a bit. It's it not that big and not super rusty I'll clean it up....v it out and jb weld it. Do I have to take off the carb and exhaust elbow or can I leave those on the manifold and remove it all as a unit and save on gaskets?

Just saying here- if it were mine, I would want to take it apart to inspect the manifold real well, to be sure that is not on its way out as well. The gaskets are cheap enough. Take it all apart, in my opinion.( it makes it lighter too)

Ever drop one of those with the carb on? I would not want to chance that either.

Good luck!

 

[boattech]

Re: Cracked block.....now what?

I normally leave the carburator on to save assembly time, But I did see one of my guys get alittle careless and nock over a manifold with the carb on it and snapped off a linkage. So it is alittle more risky.cast Aluminum parts will break easliy when a heavy cast iron manifold is tumbling. Your call on that one.

Be careful cutting a V groove in the crack, dont go all the way through or you have created a bigger void that water pressure can push on. I dont grind any v groove cause your just taking away more strength. I do ruff up the area around the crack to get the expoxy something to adhere to. and wire wheel the crack heavily to remove all rust.

 

[temperedtim]

Re: Cracked block.....now what?

I wasn't really thrilled with the idea of grinding the v anyway, just figured it needed to be done to be proper. I'd much rather just clean out all the rust with a wire brush and take it from there... If the cracks not to wide I'll just fill it with JB...if it flanged out I'll do ur hammer method. I'll post pictures as I go. Prob won't get the manifold off till Mon.

 

[marlboro180]

Re: Cracked block.....now what?

You have already made up yer mind- wire brush away if you want.....

 

[vxtech]

Re: Cracked block.....now what?

research a product called Lab-metal made by alvin products, reference to strengh its unbelievable little more cost than jb weld but definetly better and make sure you purchase solvent with it as you will need it to clean crack, seals aluminum gas tanks,iron blocks fills gouges in cylinder walls totally machinable if necessary

 

[temperedtim]

Re: Cracked block.....now what?

I'll let you guys know how it goes on Mon... Gotta get me a small ball hammer...thanks guys

 

[boattech]

Re: Cracked block.....now what?

I would really try and get something alittle better than JB weld. It is great stuff dont get me wrong. But I dont feel it hardens with the same strength as the Marine tex I use. Or maybe the stuff the guy listed above is good stuff? But I see alot of JB weld patches come in pealing off or cracked. Maybe it was poor workmanship installing it, but I just dont like the feel of it.

 

[temperedtim]

Re: Cracked block.....now what?

Well...manifolds off....cracks def a good 6-7 inches... Time to clean it up I guess...... should I chip away at the rust build up (id assume yes, carefully). Anyways let me know what you think. I see an awful lot of rust on the intake portion of the manifold, the boat sat for a long time...maybe thats why? Cracks awfully close the the head but Ive come this far so Im soft welding it and taking my chances.

 

[temperedtim]

Re: Cracked block.....now what?

Well day one prep is done...I posted a pic of my progress, not as rusty as I thought it would be, although still pretty nasty (see last post). Im curious how much more wire brushing I should do? (boattech) should I use ur hammer technique here or just fill the crack and surrounding area with JB (other stuff) and try to draw it into the crack with some suction on the water hose? I will try to find the other soft weld "marine tech" or whatever it was called, Ill shop around for it tomorrow. I glad I got into this and didnt chose to ignore it, hopefully it turns out well. Let me know what you guys think my next step is, thanks.

 

[marlboro180]

Re: Cracked block.....now what?

Grind er out , fill er up.... see what you get.

 

[temperedtim]

Re: Cracked block.....now what?

You dont think it needs any more prep Marlb?

 

[cmanion]

Re: Cracked block.....now what?

interested to see how your project turned out! i have been following this post because i ave the same exact problem right now as you do. we just put the jb weld on tonight and are waiting till tom. to test it out! let me know

 

[temperedtim]

Re: Cracked block.....now what?

Well as you can see from the pics I wire brushed it pretty good. The gap was large in some spot and not in others, if I blew on the coolant hose it would squirt from 2 spots. I sanded it down with a 60 grit just to give something to adhere to and acetoned the area to get rid of any grim. I used MARINE TEX instead of JB on "boattechs" recommendation, however I didnt drill stop holes. With MARINE TEX you are supposed to mix the whole bottle so I had alot of expoxy. I filled in the crack and sucked on the coolant hose to draw the MARINE TEX into the crack...and I saw it sinking in. I did that a few times as I slathered the exopy on. Marine Tex didnt droop much at all to my surprise and stays pretty well where I put it. I fugured I might as well use the entire slug of exopy so I put it on nice and thick and got thinner the further out I went, basically covering the entire side of the block up to the top. Its been about 2 hours and the epoxy isnt moving and is firming up nicely. I put a light in there and closed the motor cover because it supposed to cure faster with heat. I check on it from time to time. It lookes good (not literally, it looks like **** smeared on a motor) but its solid. Ill wait till tomorrow afternoon to put the manifold back on and see what happens, fingers crossed.

 

[adeneo]

Re: Cracked block.....now what?

Metalocking is the best way to repair cracks in just about any metal, lasts almost forever.

http://www.inplace.com/machining/metalstitch.html

However, I have used JB weld and similar products many times, and with the aforementioned preparations it usually fixes cracks for a short time, if your lucky maybe even years, my experience is that most of the time its only a short term fix, and the crack will reappear.

Engine blocks often have a reason for cracking, so make sure your engine does'nt have any other problems that could have caused it to crack.

 

[temperedtim]

Re: Cracked block.....now what?

No go.... not sure what I did wrong but there was def water coming throguh a pinhole in the marine tex. Hopefully it stays a pinhole because Im done with this repair....if I need a new block I need a new block, I dont run my boat on the ocean so Ill run it till it spreads or leaks to much. I thought it was solid...not so much. I took the manifold back off and JB welded the part that was pinhole leaking....who knows maybe JB will do better. Anyways thanks for all your advise....I hope it stays a pinhole.

 

[62 pipestone]

Re: Cracked block.....now what?

http://www.amazon.com/J-B-Weld-8277..._4?s=automotive&ie=UTF8&qid=1277911500&sr=1-4

I would try this.....

Anyone suggest this over the normal jb weld??

i used this on mine. i sprayed the block with paint stripper,thene after about 5 min spray with brake cleaner, wire wheeled, then with a drimel i LIGHTLY ground out a V in the crack, brake cleaned agan.
now kneed the putty to mix small amounts at a time thene take a small amount and force it into the groove that was ground,mix more and force over that. i did this til it was built up aprox 1/8in tall 1in wide and 1in longer then the crack. after that i bypassed the water in and out lets(loop the inlet hose to the motor around to the outled of the motor) thene i got some block sealer from napa(NOT STOP LEAK)and folowed the derections(make shure to also use muffs or you will ruin your water pump in the O/D) whene your all done lay a thick coat of paint on it ,reattach your hoesis and go boat

 

[temperedtim]

Re: Cracked block.....now what?

So now that ive made a big mess of the side of my engine block can I try again? Meaning can I get in there and remove any of this marine tex? Or do I try to now fix the pinhole in the marine tex (lol, kinda)? Ill be shopping for a new block, but I might just run this one and see if I can get the season out of it. Or tear it down and try patching it again?

 

[marlboro180]

Re: Cracked block.....now what?

So now that ive made a big mess of the side of my engine block can I try again? Meaning can I get in there and remove any of this marine tex? Or do I try to now fix the pinhole in the marine tex (lol, kinda)? Ill be shopping for a new block, but I might just run this one and see if I can get the season out of it. Or tear it down and try patching it again?

Well, since yer from Maine,

Ayuh, that pinhole would suck wicked bad....

I would grind it out a bit at the pinhole, gouge out a little around the same area , scuff it up with some 36 ( ish) grit sandpaper , get the dust off, and apply some more marine- tex.

I would also look around for a good block as you are already thinking about doing anyway.

 

[62 pipestone]

Re: Cracked block.....now what?

i think it was bad prep. see my reply above and hear is a link of something simaler to what i used
http://www.steelseal.com/?gclid=CMeg3dnH3aICFRA4agodRR3G6A
the stuff i used was like $20.00 @ napa