Well here is what we found on tear down. First, the engine was making a clanging sound and running poorly. So we pulled the dipstock and found that it had lots of coolant in it. Then the rocker arm cover came off. We had found the bent push rod the night before and I had swapped it for a spare. So we pushed the truck into the barn and began tear down. We were thinking sticking valve, broken lifter, somewhere in that neighborhood. The engine had belonged to a very poor family previously, so we figured maybe something else was worn, but we could not think of what it was because of the going over.
So off came the side cover- lifter was in good shape. Then the manifold. Then the head. One thing jumped out at us. Not all of the pistons were at consistent levels with each corresponding piston. #2 was completely topped out. So much so that it had markings of the head on it.
So off comes the pan.
The Rod on #2 had broken just behind the Wrist Pin Clamp Bolt. The rest still attached to the piston. We pulled the rod cap and pushed the piston out of the top. All components still had assembly lube covering everything.
What it looks like is material failure of the connecting rod. I have never seen one break in this manner before. When it broke it layed over against the drivers side of the cylinder as the piston went up, when the cylinder fired it broke the piston skirt off that side and forced the rod through the cylinder wall into the cooling jacket. Then it did similar damage(more of a crack) to the passenger side. Wirst pin is clean and in good shape. infact, other than the #2 piston and rod, and the #2 cylinder, everything is great on the engine.
So some thoughts were to pull everything and put in a spare engine. Now I am thinking about sleeving the cylinder and continuing to use the engine. the rod and bearing shop will exchange the bad rod at no charge, the new insert bearings are fine on that rod. So tomorrow I think I will start calling around to machine shops to ask about the insert process.
Originally I thought about putting my spare 41 216 in, but I like the insert bearings, and a lot of the benefits of the later 216. Hotrod Lincoln and I have been messaging about it, and I think it is not a bad idea. I am used to working on many antique tractors with sleeved engines.
I will let you know what I find.
Still heart wrenching though. It was running better than ever.
So thats the story.
