Back in the mid-1950's one of the sponsors of the family race car was a trucking company that had a chassis dyno in their maintenance shop. Dad did a lot of race tuning on that old '34 Ford coupe with the alcohol-fueled flathead V8 on that dyno. Once they solved the wheelspin problem by building a ramp onto the rear bumper and pulling a road tractor partway up it to load down the racecar rear wheels, they started tinkering with ignition timing and carburetor mixture.
Once the fuel mix was sorted out, the ignition timing would be advanced one degree at a time with the engine running at full throttle until the horsepower maxed out, then the timing would be advanced one more degree, and the power loss recorded. Back to max power, and start retarding the timing. It was necessary to retard the timing 5 DEGREES to lose as much power as just one degree of over-advance would drop!
When in doubt, DO NOT over-advance ignition timing!
Jerry
