Cracked block on my zc!

[xXHondaBradXx]

Hey! I just finished a DOHC ZC swap in my 91 hatch. After starting it up, i noticed it was leaking oil. I took the intake manifold off to find the problem, and found that there is a crack in the block, right where the oil pressure sending unit is. its about 2cm long. Will getting it welded fix the problem? Has anyone ever had the same problem? Any advice would be great.. thanks.

 

[phyregod]

Depends on why the crack is there. Should be able to have it welded up by a competent machine shop, but you're looking at pulling your motor completely apart, having it welded and re-machined, and putting it all back together again. I don't think they could just weld it from the outside and it be "ok".

I'd almost bet that the motor tossed a rod at some point and did that.. Someone tossed a new rod in it and sold it off. But who knows. It would be cheaper to part that motor out, make what you can out of it, scrap the rest, and buy another ZC.

 

[xXHondaBradXx]

the crack was caused by the oil pressure sending unit being tightened to much.. thats were it is...right at the end of where the sending unit screws in.. directly under the water pipe..

 

[xXHondaBradXx]

 

[xXHondaBradXx]

in this pic..the very end of where it screws in...its not that long of a crack.. i really cant afford or get my hands on another zc block.

 

[xXHondaBradXx]

not the same engine...just to give you an idea of where it is..

 

[boostin4fun]

Grind the area around the crack slightly, clean it up with some thinner or brake parts cleaner and JB weld it. It sounds ghetto but I bet it will work just fine and its a cheap solution. My moroso oil pan cracked where a bung was welded in for the oil return line. The pan was outside of warranty so I did exactly what I described above and have had no leaks whatsoever in the last two years.

 

[phyregod]

Ok, being that it sticks out from the block so far (you mean the threaded area cracked) as long as the welder can get to both sides he should be able to weld it up, re thread it, and call it a day.. I thought you meant the actual block (wall) was cracked.

 

[xXHondaBradXx]

yeah its the threaded area thats cracked...what do you mean by JB weld it? Is this crack a big problem? Thanks guys.

 

[xXHondaBradXx]

Will i have to pull the whole engine out?

 

[phyregod]

JB weld is an epoxy.. Its strong as holy hell and has been used to "fix" such small cracks in engine blocks.

I had a cracked transmission housing in a pontiac that I actually JB welded back together and drove on for a couple of months before it failed catastrophically. I was impressed. Gave me time to save up and source another trans.

If I were to try that on this application, I would rough up the surface all the way around, clean the hell out of it, inside and out of the crack, mix up the JB weld, massage in into the crack, and all the way around the piece, then put a hose clamp around the whole thing, tighten it down, and apply JB weld over the entire clamp. Chase the threads to clean them up. That way you have a sealer and support so it doesn't crack again when you put the sensor back in.

This is ghetto as hell but it would probably work.

Do it right, take it to a machine shop! lol

 

[GlassHeadlights]

Devcon is the same as JB Weld but almost twice as strong. A tin of it is like $100. My 2 cents.

 

[xXHondaBradXx]

Alright.. Thanks for the help guys. Like I said. where I am, I can't get my hands on another dohc zc unless I order it. And I dont wan't to end up having to buy the complete swap. I would order, if I could just order the block. So I just have to fix it. If anyone knows a site to order just the block, then hit me up with it. thanks

 

[xXHondaBradXx]

awesome..i got some devcon..it worked great..no leak...thanks guys!!!

 

[GlassHeadlights]

Sweet.