I've had my block about 6 months now. I sent off my b20b to get sleeved, got it back all is good. Ran strong b20b/vtec 300whp, sc61 turbo. Well about 2 weeks ago i notice water dripping out from behind my turbo, Upon inspection my block is cracked about 5 inches behind the dipstick tube near the bottom of the cylinders. Has anyone even heard of this happening? This thing was supposed to be bulletproof!@. Any idea what would of caused this? My best guess was heat expanding the ductile iron cracked the aluminum. Possibly harmonics? I have no idea. I run a really conservitive tune 11.0:1 a/f. Engine still runs great. just sprays water all over the turbo. I asked a local aluminum welder if he could weld it up and he told me there was no way he could weld it. Any ideas? I thought about JB welding it up but i doubt i could get it sealed behind the dipstick.

 

\ive seen that happen before... not ge's fault, just your block was made on a bad day.. next time dont do b20 block.. go with a gsr or ls block.. ive had some crazy **** happen with my b20b's and 1 b20z.. glgl

 

Sux, if it isnt into or mixing oil with the water passages, go to any reputable welding shop and have them patch it up. I had a few customer come in with blocks that had holes in them from throwing a rod, as long as there was no internal damage and passages that were not damaged beyond repair, I sent them out to a shop that use to weld **** for some big name NASCAR teams, they do killer work on aluminium, and the motors are still running strong to this day, one puts down 340ish WHP and the other is about 360ish.

Just sad to see you waste a sleeved block. If it can be saved, why not ??

Good luck with it..

 

100% you can use jb weld

Ive seen it done atleast 3 times in person and it holds fine

Its cheap, its easy, it works, the color will match lol

Seriously, consider it as a serious option.

I seen a guy fill a LARGE hole with jb weld when he was cutting the webbing of his block to fit the turbo, ground to far and made a nice sized hole, filled it with a tube of jb weld and it held MINT

It can be welded though, i just dont think its worth the money

 

if using JB, which should work fine, clean the hell out of the block. NO moisture, NO oil, and it should hold fine. its rated to 600+ degrees F, and is strong as hell when prepped fine. what have you got to lose? might as well try it first

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by redzcstandardhatch &raquo;</TD></TR><TR><TD CLASS="quote">if using JB, which should work fine, clean the hell out of the block. NO moisture, NO oil, and it should hold fine. its rated to 600+ degrees F, and is strong as hell when prepped fine. what have you got to lose? might as well try it first</TD></TR></TABLE>

I'm not saying that JB weld won't work, but if it doesn't it's hard as hell to clean all of it off to be able to have a good weld after that.

The best way to repair a crack is to drill a hole like 1/4" to 1/2" away from each end of the crack and then weld the whole crack up to the drilled holes. Also helps to figure out if there's any visible cause of the crack to prevent it from happening again.

 

yes, i completely agree with you man.

that is the best way, but maybe not the easiest. it will be a BITCH to clean around that dipstick

 

I saw a block crack like that before. Benson was able to weld it up and it is currently working fine at 670whp. The trick is to weld it with the head still torqued down. You will have to remove the dip stick tube, however.
That cracking can happen when too much oil is used on the head studs when installing them in the block. It kind of hydraulics the block in that area until it cracks.
Because of the location of the crack, you CANNOT use JBWeld there. It is too close to where the head studs attach to the block.
Find a good aluminum welder.

 

Yea befor i took it apart, I bought a dremel and some jb weld. But im not sure how good i can clean behind the dipstick tube, or how long it will last. But I guess its worth a shot. I've heard lots of success stories using jb weld. But they all said get the surface super clean and dry, make a little valley with a dremal and mix the jb weld really good force it in the valley and let it dry for a while, good to go. I'll let ya know how it goes.

 

Read the post above

 

the way I see it if you paid to build a sleeved motor why cheap out on a patch and use jb weld over an alum weld?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by sp00led &raquo;</TD></TR><TR><TD CLASS="quote">the way I see it if you paid to build a sleeved motor why cheap out on a patch and use jb weld over an alum weld?</TD></TR></TABLE>

It's not really cheaping out, it is 1000 times easier, and if it works as well as welding, but is cheaper/easier... why not?

 

Seen it before on a D series block that had a block gaurd sledge hammered in with 50 miles on it.

 

**** man that sucks.

Like earl said take the block out or get someone to tigg it in the car make sure its clean as expletive Acetone.

Josh

 

""the way I see it if you paid to build a sleeved motor why cheap out on a patch and use jb weld over an alum weld? ""

I have to agree with this 10 fold, you spent the money to sleeve it, have it welded and be done with it. like earl said, being so close the the stud holes the heating up and cooling down can cause the JB weld to break loose and if the crack increases like a winsheild the issue will only get worse, yea sure JB weld has its purpose and works well in alot of situations, but done use it in this one. The cost of the weld should cost you less than $100. as filling a silver dollar size hole in 1 of my customers block cost me $90.

Do it right the 1st time, of save some cash for the next 3 times

 

if he said he couldnt weld it, i wouldnt let him weld a bicycle frame.

that **** can be welded with a competent tig welding man.

 

Well From when I talking to Alumimum Welder. He told me that he has welded a few Honda blocks and that they have all recracked after he welded them. And the problem was that the material that welds the alumimum together is denser then the honda aluminum and dosent expand the same. So he then used jb weld on the last couple blocks and that they still holding up strong and that the jb weld must expand around the same rate as the aluminum, and when applied correctly jb weld is really strong stuff and he highly recommeded trying it. He might of been BSing me thou. Not sure why he'd turn down business.

Could the Head studs being too tight cause this crack? I havn't thought of that. I do have my head torqued down pretty tight. 78lb arp.

 

If he has a steady work load of easy stuff, he might be BS'ing and turning down 'hard' stuff. He probably can't deal with the way cast aluminum 'sweats' when its welded. That area shouldn't be that bad, since its really not in an area that touches much oil or heat.

 

i think the big problem with aluminum welding that spot is there is a risk of distorting the cylinders.

i have seen it happen LOTS of times before where the outer aluminum was welded and the heat distorts the cylinders.

the only way to weld that properly is to pull the entire engine apart. pull all the internals out. have the crack tig welded then have the cylinders measured/honed and then fully re-build all over again.

$$$$$

i say screw the JB weld..........use devcon liquid aluminum and hope for the best

 

Well it does sit directly behind the turbo. Im sure that part see's more heat then any other part. Drag 3 Cast turbo manifold. He did mention that cast aluminum dosent' like to weld unless its super clean, and even then its a neusance. I'm gonna give this jb weld a shot just got done drilling my holes at the end of cracks, Trenching out the crack and cleaning up the entire area. If it dosent work i'll give a great deal to anyone who wants the block. $200 bucks and its yours. I have a couple gsr blocks sitting around im gonna use if this dosent work. Stock block will hold what i make easy.

 

u can also use liquid glass and pour into the radiator. hope all goes well later mike its stevie lol