So i'm told that I can run 87 octane in my motor, no problem. Most of the gas docks on our lake only have 89 or 93, but I generally fill up on shore anyway.
Last year I ran 89, and had the timing bumped to 11 degrees base, 31 total (stock is 8 base, 28 total). This year I rebuilt the carb, filled it up with regular, and set the timing back to stock.
My question is, can I safely run any extra timing with 87 octane? Should I stick with the stock timing and run 87, run 2-3 degrees extra and run 89, or run 2-3 degrees extra and stick with 87?
Motor is a 502 mag, carbed. totally stock except a rebuild a couple years ago. 20 degree t-bolt IV module. stock timing is 8 degrees base, 28 degrees total. When I bumped the timing up to 31 total, i picked up a couple mph, but that was running 89 octane.
Also, under what circumstances do I need to be concerned about running E10? I understand the engine will run leaner on 10% ethanol, is the carb set up rich enough from the factory to deal with this?