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Almost every time a timing question comes up on the forum, almost everyone here says to advance timing just before pinging occurs.
Does this mean we should not pay attention to factory specs? Or were the factory settings for easier starts, better economy....or just wrong??
 

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Fuel quality is greatly degraded from the good ole days when these engines were designed. So, ignition curve, chamber design, and initial advance are really all wrong with modern fuels.
 

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Fuel quality is greatly degraded from the good ole days when these engines were designed. So, ignition curve, chamber design, and initial advance are really all wrong with modern fuels.
I read engines tested on a dyno: 9:1 to 9.5:1 peak hp with 38*-42* total advance.

Engines with 9.5:1 -10.5:1 35*-38* total advance

If we should follow this, I'm confused about the 9.5:1 group
Mine is a code F 9.5:1 with a street cam and I checked the distributor, it reads
10 (20 degrees mechanical advance) I set my initial at 16* then road tested up
a steep hill full throttle and advanced further. When I retested with my timing light
I read 20* degrees. I'm told my harmonic balancer may be inaccurate.
My question is: What do I use to read total?
Then if I deduct 20 degrees I should come up with what might be safe??
But now back to both 9.5:1 throws me a curve. I guess with code F answers that (low)
Next question: Has this total for low and high compression 302" changed?

Plus I read never exceed 36 degrees total! Now I'm totally confused!
Low "F" 38*-42*
 

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1. Get it to actual 0* static and then see what your pointer points to. If it's 0, then that's nice. If not, maybe mark it for 0, 5, and 10, with chalk
2. Check and set the timing.
3. Total timing should come in as the engine accelerates, so see when it stops increasing and levels out. Note the rpm and amount.

Swapped distributors or replacements can have the incorrect timing curve for your particular engine. So, mapping out the timing curve is a good idea if you have an old original distributor or an aftermarket. Just plot how many degrees at certain rpm on a graph and connect the dots. Do it in, say, 200 rpm increments.
It helps to have a lovely assistant or Ninjetta.
 
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