Brian....sorry for the delay...have been out of town for last 5 days. I used just a piece of 1/4" dia craytex (rubberized abrasive) extended from a collet in the mill and dressed it several times during the process.
A short update to the work on the pump over the last day or so, some bling, which is uncharacteristic for me, and I received yesterday the globe valves from PMR, one of which will be for the priming cup which I still have to make. A few pictures follow
Here is an initial video of the engine under power. It not finished yet but the final plumbing and valve work can be done while I am painting the rest of it.
Charlie, you may have seen already some of the hoglet and webster build logs which may be a starting point. Not sure they are true beginner models but depending on skill levels and experience, probably doable. There are far more experienced IC guys here that I hope will offer further and no...
Welcome Zane, and thanks for the introduction. Hopefully some of the members more into multi-cylinder small IC engines will be able to help with your question. Some pictures of the "beast" might be helpful too.