The 1983 R80ST top end is the same as the 1983 R100RS with the exception of a smaller cylinder bore, piston and rings. I already thoroughly documented installing the engine top end for the 1983 R100RS, so I reuse a lot of that material, as appropriate, in the documentation and the summary video for the R80ST below.
Here is the document and video links.
VIDEO: 1983 BMW R80ST Install Engine Top End
Here is what I started with and the final result.
The cylinders and heads were vapor blasted and I hand cleaned the engine block. I repainted the inner timing cover and top engine cover and had the frame powder coated.
Here is the engine with the top end installed. I put shop rags in the exhaust and intake ports of the heads to prevent anything from getting inside. I also put red tape on the temporary spark plugs and on the dip stick to alert me that I need to install new plugs and oil before I start the engine.