doing an oil change the other day I noticed a hairline crack about 50% of the way around the #1 cylinder exhaust outlet on the manifold.. doing some looking on line I found 3 other machines for sale and all indicated "cracked exhaust manifold and the pictures showed the crack to be identical to mine.. I checked with Finning, and not only do they think this part is made from gold, and not some form of cast iron, the part has never been upgraded to prevent cracking from occurring.. it's a tight crack with minimal exhaust leakage.. considering the high cost of a replacement that is more than likely destined to crack, I'm going to just let it go for now.. my machine has just over 2K hours on it and I suspect it's been cracked for a while.. does anyone know of an aftermarket design that would be an improvement of the OEM, or someone that has decent luck repairing an exhaust manifold.. on line search was a bust.. Bernie
U could repair it but it is or will be warped. That's a naturally aspirated engine right? Sounds like another fabrication job to me if it's a known problem and u can't find any aftermarket ones. That Mitsubishi engine has to be used in a lot of different applications u might find one with a different exhaust configuration that could fix it. Maybe an ag pump setup or a genset one.
cast iron can be tig welded to fix cracks,( you can use other welding ways, but tig has more control and I use a stainless steel tig rod as it seems to have some flex to prevent cracks, doesnt always work, so its a piece by piece deal to see if it works) if the cast iron isnt so deteriorated that the edges just break away by taping on them..
You have the right idea leaving it alone if its not leaking to bad welding repairs on a cast manifold will lead to disappointment after all you cant make it stronger and it broke the original one...
Yair . . . As mentioned by Hobbytime good cast iron can be successfully welded with the TIG . . . and even such things as manifolds can have stiffeners and plates added. When welding always have the manifold bolted up or bolted to a jig or heavy work bench. A bit of warping can be taken out with a linishing belt if there is a big enough one around. What I am saying is there is mostly no need for expensive set up and truing on a mill. Cheers.
thx for the reply's I know weld repairs are hit and miss, and you can induce warping.. I've seen cast iron weld repairs before and it seems there is a tendency to recrack on the side of the weld.. as I said in the original post, unless there was an improved part to install to preclude the obviously destined cracking or until the crack becomes a major issue it can just stay the way it is.. it's tight and has minimal leakage..
Just TIG up a nice longtube header for it lol.