Tuning with jets, Power valves and an O2 guage

Frankenduster said

I just ordered the Mallory kit PN 29014. It has different advance springs to tailor the curve in several ways. Some guys have mentioned to try a two-stage curve. The first moment of advance is a bit fast but then at a point the advance rate slows. This is actually designed for the very thing that I am fighting.
IF....this makes the difference, you can be sure that I will admit my stubborness and apologize.

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That was the kit I have - I mentioned a couple pages ago that i'd mai lyou some iof you needed them and that you needed to slow down the curve - just as Rob has - over and over.
If it was in my garage I'd be dropping the initial to 12-14°, it would START coming in at about 2K, and FINISH about 4K for a total of 32°. Then I'd use the O2 to tune the carb.
I've had several big blocks with no quench - properly tuned - running great on local 89 octane with 10% ethanol that had 185psi and iron heads. It can be done - you just have to have the time, knowledge, and bits of parts to do it.

It's back in this thread - detonation and ping are self supporting. Once they start during an acceleration event they will stay unless the throttle is backed out of. So if it pings once at 2K - it's going to continue until you let off and change the air/fuel input and ignition input. That's why you have to alter the timing curve - not just one part of it. Then you'll probably have to reset the carb too - especially the accelerator pump circuit and power valving. There's a ton on quench online - if you don't get it - keep reading. If you don't want to accept it - keep reading. The short shortshort answer - less is more. Tighter is better - really tight is best, and after .045-.050 - there aint much good happening especially with a big bore and piston rock.