[Cliff R]

Good plan. Total potential timing at cruise is right for what you are doing. I've tuned hundreds of older high compression engines to run on this new fuel and they ALWAYS like about 10-15 degrees additional timing at light engine load. They NEVER like, want or respond well to super quick all-in timing curves right off idle (many show up here that way).

Most folks do NOT understand the mechanical advance portion of tuning. These engines require a timing advance curve simply because we are bound by the laws of physics with these things. To accomplish complete/efficient combustion the timing must start sooner with increased engine RPM because we have LESS time to get it done as the cycles per second are increasing as well. With a very well thought out engine build, optimum compression, cam making good cylinder pressure, tight squish, etc you will NOT need a quick curve or "all-in" early. Well thought out engine builds will like LESS timing everywhere as they are more efficient. On the other end of that spectrum you have the guy who "lowered the compression for pump gas", then installed a cam on a tight LSA that bleeds off more cylinder pressure with it's added overlap, so it will LIKE, WANT, NEED, and RESPOND WELL to a LOT of initial timing, plus a really quick timing curve to help it be more efficienty at low engine RPM's.

It's just physics with these things, and ALL of these N/A engines end up with simliar if not near identical timing curves no matter what brand they are. It's all about CID, static compression ratio and cam events for the most part. Of course some engines are simply more efficient than others based on design, and some older varieties had HORRIBLE combustion chambers designed for emissions, so in those applications you may find yourself pouring more fuel to them, and throwing more timing at them to make them happy........