I broke down the engine. #2 has some scoring from where the head gasket seal ring came apart and dropped into the cylinder. These are deep (about finger nail) and go half way around the cyl. How much can this be honed or does it need a sleave? I haven’t worked with aluminum blocks before.

 

The blocks are alusil, and can't really be honed in the traditional aspect. If it is bad, then the block will need to have machine work, and probably will need to be resleeved. Unfortunetly it is not a cheap process either.

 

So, rather than spend a fortune on sleeves for my block, turning the crank, etc,etc, I bought a 87 944 engine (used). It has a new water pump and good belts. Looks like new rollers and front seals. The bad news is the oil is black. The worse news is that on the lower balance shaft, the bottom 8mm bolt that goes threw the balance shaft bearing was broken off (bolt was still in hole). The two 6mm bolts on each of it are ok and appear to have the proper torque. I removed the BS cover and the bearing is a bit worn, but the shaft journal looks good. Any Idea on what caused this or what I should do to fix it?

 

Just like any bearing, they will wear over time, replace them, put in the new seals and slap it back together and you should be good. I would dump a couple of quarts of oil through the engine with the drain plug removed to flush some of that old oil out. I usually flush at least a half quart to a quart of oil through on every oil change to try and flush everything out as much as possible.

 

The broken bolt is really no issue, just a wierd thing or an over active wrench by the previous owner?