1974 C-160 rebuild engine rod failure?

[duke 49]

I recently rebuilt my K-341 and just had it for another run when it lost power slightly and just dropped the connecting rod? I just hope that it didn't scar the bore! Perhaps the bolts were not tight enough on the journal? Any simular thoughts on this would be greatly appreciated.(Also, I removed the "grenade" gears during re-assembly). This was a short block I bought in pieces so the rod & piston were re-united.

I just put a suction cup on the piston to have a look and the journal is scarred no sign of the bottom end of the rod! So, it appears the rod cracked, began chewing up the journel and finally brokel

The bore is good. So now it's time to have the extra crank polished up and a matching rod joined up for another rebuild...The fight goes on!

[rmaynard 16,287]

When the rod was installed, are you sure that the lubricating hole was positioned towards the cam shaft? Was the cap aligned properly? It should have aligning notches or marks. The crank pin may not be scarred and might just have aluminum stuck to it. That can be cleaned off by soaking in muriatic acid. You may be lucky. This could be a simple fix.

[duke 49]

The lubrication hole was positioned towards the cam and the cap was aligned. I'm thinking because it was apart before and I didn't use blue lock tight? Also, running without the balance gears, could that have anything to do with it? I will look at the journal again, I hope that it is just aluminum! Muriatic Acid can be found at a hardware store, same chemical used for etching? Thanks duke

[squonk 43,678]

I've got a 341 apart. Took it to a friend who builds racing engines for karts. Rod look good to me. He called and said rod was junk. He has a special dye to check aluminum for fatigue. Cracks every where. Took the block and crank to a machine shop. Crank was all ready .010" under. Now it's .003" out of round. Can't be turned again. Welding and returning about $300. New crank is over $300!! Block is ok but needs boring. Piston almost $250. Want to use Kohler parts and that's what he recommends. I'm going to look for another running 16 or even a 14 for a spare engine. I would get the other crank and rod checked before another blows up If I were you.

Edited November 18, 2012 by squonk

[duke 49]

I am trying to reach A-1 Miller to get a nice rod with the bearing upgrade. The journal has aluminum melted unto it, which I hope to remove with Lye. I did find out my extra crank is also out of round and the piston has a small chip along the skirt! I do have another rod and piston left. This has been the most difficult tractor ever! Only because it is my last rebuid for sure! (Last Wheel Horse) Parts for wheel horse are getting way outta hand!

A-1 Miller just got back to me and he can do the rod insert as needed for 108.00. That would be great due to the fact that the engine would begin to "knock" when the inserts are worn and when they are replaced the journal would remain, s-m-o-o-t-h!