Cracked Crankcase

[rocketnorton]

ya, that be fugly to weld.

 

[Colt Marlington]

I wouldn't rule out welding on just about anything. I've had the inside of a motorcycle crankcase welded up at a transmission shop.
Some talented welders can fill some pretty big holes in cast metals.

I watch this guys videos sometimes. He seems real knowledgeable. I know this isn't exactly comparable, but just an example of what can be done.

 

[a. palmer jr.]

Got the tank off and de-greased n cleaned as much as possible. blsnelling was correct in that the crack does not appear to be going into the sealed part of the engine. But it is long and zig-zags all over the place. Going to go ahead with the epoxy using the methods recommended. Welding is out so nothing to loose! Also considering using the dremell with a carbide burr to slightly V out the crack on both sides where possible.

I suppose the more area for the epoxy to adhere to the better so veeing is a good idea...

 

[user 122190]

Looks like you can clamp it somewhat. Epoxy clamped is superior to just Epoxy as a filler. IMO, any V'ing isn't going to get you anything. If you think it is something to do make it sloppy. A rough surface gives the Epoxy more area to adhere to.

 

[Canyon Angler]

Since the crack doesn't go all the way through, I don't think clamping is going to do anything for you. Unlike wood glue or Crazy Glue (for example), the thickness of the glue joint doesn't really matter with epoxy, so long as the two surfaces to be adhered to are fully wetted out properly.

And clamping to the point where the crack closes up could distort your pieces.

If anything, being that the crack is so narrow, I might fill the crack with epoxy and then "cap" it with a paper-thin layer of epoxy-soaked carbon fiber or super thin strands of fiberglass going perpendicular to, and bridging, the crack, to give it a bit more tensile strength across the crack, like this (with the "V" being the crack and the "––" being the "cap" of fiberglass or carbon fiber):

––
V

Good luck and let us know how it works out for you.