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Mudrig150

2 Engine rebuilds

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Mudrig150

The K241... well, I have some bad news about it.

The piston is super sloppy in the bore. Looks to be able to move about .010-.020" in each direction.

Although... It is loose in ALL directions, which is very odd for wear, which usually happens along only 1 axis, the direction of the rod (perpendicular to the crank, where all the side to side stress is). Also, there is literally no stamp on the piston telling what size it is. Top of the bore is so full of carbon I can't get a good reading on the bore size, so that's a problem. Also, the piston head comes slightly higher than the top of the bore... Not sure that's supposed to happen. Also, most worn out oil burners I've seen have had one thing in common: A broken head bolt. Usually it's either one next to the exhaust, but on this engine, none of the bolts broke. There is also no oil on the piston, only sludge.

So, that needs some further investigation. If it's bad, it's getting bored out to a K301, and if not, it's getting the correct piston size. What's the size of the piston itself, not the bore?

 

For now, I'm rebuilding my junker K321. Bore is clean and measured between 3.4995 and 3.5005, and there's no damage to the block from the 2 broken rods (First from low oil, second from backward rod). Using a totally different crank and rod from another K321 and the original piston head, which fits nicely in the bore. The rings seem good, no damage, and the only damage to the piston head is a small chunk broken the size of a sesame seed out of the area between the top ring lands where someone must've gone full gung-ho with a whacky stick.

Damage control:

Block survived with only a scuff on the side opposite the cam.

Oil pan was bent to hell and ruined, but I'm using a different pan anyway.

Camshaft has a small dent between the lobes, but still rides true, with no broken gear teeth.

Governor has no damage.

Bore has no scuffing, only the kind of bad crosshatching.

 

I gathered all the parts, and I have a full gasket set, so it's going back together.

20191111-181428.jpg

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oliver2-44

Good luck on your rebuild.  Remember, Cleanliness is next to Godliness, 

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Mudrig150

So, guess I'll just get the K241 rebuilt as a K301 for the extra torque. Got a crank and rod from the K321 and I'll get a new piston head for it.

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