Hi not 4x4 related but not for chit chat either.

Im working on putting together a V6 from a Mazda 929. It blew the head gasket and while rebuilding the motor I found this.......... A small hole between the water passages on the block.
Further more the hole looks like a flaw in the casting of the block.
This motor only has 78k miles on it!!!

What can be done to repair it???

Here is that side of the block.

Thanks for you help.

Weld it up.......if you can't....find someone who can.....it's only aluminum........weld it.... grind it....resurface it.....drive it till it breaks again, than start all over again!

Originally posted by 1BDYJ
Weld it up.......if you can't....find someone who can.....it's only aluminum........


Its a Steel block with Aluminum heads, The crack is on the Steel block and its still in the car.


BUT thanks for your help just the same :)

well shit if its steel, weld it adn grind is smoothe...

Aint got no welder:confused: :(

The car would have to be towed to a shop. Plus isnt welding cast iron difficult? And with the motor still in the car wouldnt be hard to get a perfectly flat surface on the block after its been welded on? Im looking for alternate ideas.

crk sorry, didn't even realize you said "block".......duh!!

I would try some JB Weld or some kind of epoxy, sand smooth, use a really good head gasket and get Some KW Block Seal and install in engine. When using KW read instructions and follow to the " T". It should work just fine. Good luck

Originally posted by 1BDYJ
crk sorry, didn't even realize you said "block".......duh!!

I would try some JB Weld or some kind of epoxy, sand smooth, use a really good head gasket and get Some KW Block Seal and install in engine. When using KW read instructions and follow to the " T". It should work just fine. Good luck

I would use the quick steel stuff...it works way better than JB Weld...the proper way would be to wled it though...

Oh, can I ask why are you rebuilding the engine after only 78K miles???

Originally posted by Supergper

Oh, can I ask why are you rebuilding the engine after only 78K miles???



Yes,

1st) becuase its a mazda (piece a shit except the rotary engines)
2nd) because the head gasket blew, because of the hole in the block.
3rd) reread: Further more the hole looks like a flaw in the casting of the block.

Get a copper gasket and put it back on and torque center out...had a paper gasket before and with a improved seal area gasket it will be all good...can get them at Autozone.....

That does not look like such a big deal..... it looks like it's a flaw that leads to a water jacket.
is there a visible crack that goes to a cylinder?
was there a water leak from the head coinciding with the location of the flaw?
If that flaw was leaking into the adjacent cylinder there would be NO crapola on the piston (the constant "steam cleaning" from the leak would change the color of the carbon buildup)
Was there white smoke from the exhaust?
As for the repair.... it should not need welding as it should be encapsulated by the new head gasket... maybe some metallized epoxy for a belt and suspenders type deal.
The one big thing you should have checked is the aluminum cylinder head itself... Mazda cylinder heads have been known to warp.. break out the straitedge and feeler gauges... you may need to have the head levelled at a machine shop.
have fun
:D

CRO,

Yes that hole leads to a water jacket and there is no hole in the wall of the cylinder. The #3 cylinder was full of carbon build-up. my guess is that it was from the anti freeze. The other two look as they do in the pics above, the heads are back from the machine shop. The guy there said one had a small warp to it and the other was fine both were cleaned pressure tested and milled. The heads are ready to go! Its the block that has me scared!


Oh yea, yes lots of white smoke and no water in the oil and no oil in the water.

Any good machine shop can fix that. It's the same method used to fix a crack.

Originally posted by CRO
That does not look like such a big deal..... it looks like it's a flaw that leads to a water jacket.
:D

Exactly. It doesn't look like diddley. Those two big holes on either side go into the water jacket too, but they are no problem. It blew a head gasket, but that little POS flaw probably didn't have anything to do with it unless it sticks up above the deck. Button it up and be done with it.

from the looks of those pistons, doesn't look like any one of those cylinders had water in them. Which cylinder blew??
Yes the copper gasket will seal better than OE gasket, I would inspect old gasket very carefully to see if you even had a problem with that side of the engine. Obviously your gonna keep the car, so I would suggest fixing it properly or your gonna be doing it again real soon...jmo, good luck
ps.. water in cylinder cleans carbon off, doesn't put it on