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Discussion Starter #1
Thanks everyone for your help on my last post.

I got the distributor installed and ran the engine with no problem.

Now I need to adjust the advance. I did turn the dizzy and tune by ear (I'm no expert so I turned it to what sounded good). But I have a timing light and I would like to set it to the preferred degree.

What is best for a mild build street driven car? Can you walk me through the theory?

Thanks!
 

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Some of that depends on how much total advance your distributor adds in. At the top end (past ~3000rpm), your total timing should be between 36 and 39*.

Most people set their initial timing between 10 and 14*. However, some cars run better with more or less. So here's what I'd do were I you: first, find out how much your distributor is advancing (with the vacuum advance plugged if equipped). It will likely be 20*, 26*, or 30* IIRC. Then, find out what initial advance your car "likes" if you can tune it by ear. If tuning by ear is iffy, then I'd suggest a vacuum gauge - wherever your vacuum maxes out is more or less where the car is happiest at idle. If that initial advance where it's happy, plus the amount that the distributor advances total, is between 36 and 40 degrees, then you're set.

If, like me, your car likes more initial advance than is safe to run, then you may have to tinker with the distributor a bit to reduce the amount that it is advancing total. As an example, my car likes 18* initial, but the distributor advances 26* which would cause it to have a grand total of 44* advance (way too much). But if I make it so that the distributor only advances 20*, then my total advance would be 38*, which is perfect. Limiting the amount of advance can be accomplished by basically limiting how far the weights inside the distributor can travel. That's not something that you should have to mess with with a mild street motor, but if you run into that issue, there's a few ways to do it and a lot of people here know how!

Hope that was clear and helpful.
 

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Discussion Starter #3
Am I understanding this correctly?

The more you advance the timing the sooner before TDC the spark plug fires. This results in a longer more complete burn which equals more power.

Of course it needs to be tuned for each build and too much advance or too little advance can be bad (or just not optimal).
 

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My theory has always been to run as much advance as the motor will tolerate without pinging. Advance 2* at a time until you get pinging under load and then back it down to the last "safe" setting. Without a dyno I think that's about as close as you'll be able to get.
 

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My theory has always been to run as much advance as the motor will tolerate without pinging. Advance 2* at a time until you get pinging under load and then back it down to the last "safe" setting. Without a dyno I think that's about as close as you'll be able to get.
I'm not sure you mean by ping. I assume it's a sound. Where does it come from?
Can you provide me more info on this?
 

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My theory has always been to run as much advance as the motor will tolerate without pinging. Advance 2* at a time until you get pinging under load and then back it down to the last "safe" setting. Without a dyno I think that's about as close as you'll be able to get.
This is exactly what Dan at G/N told me to do after he rebuilt my distributor a couple months back. I settled on 12 degrees BTDC on my 336K mile A-code 289.
 

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Bartl got it right on. You want as much advance as possible without ping, detonation. Higher lift cam can take more advance. I ran 44 total with a serious cam, for many years. Stock or mild, you guys got it right on, above. McKay, ping is the knocking sound coming from the engine when you get on the gas at very low RPM with too much advance. Start by finding the limit for your initial advance. Back off from there a bit. Pinging is hard on the engine, not good. Then you tweak the rate of advance and total advance. Usually by 2800 RPM for total. I run passes with a stop watch at higher RPM as one more way to dial in total advance. Say 3000 RPM to 5000 in 2nd gear. Different springs on the weights under the distributor top plate are a common way to adjust rate of advance. Of course, I have no idea what kind of dist you have.
 

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Hmm, I never could tell what pinging sounds like. I'm sure my motor's done it before, but I just cannot figure out what the noise is supposed to be and everyone says it's obvious but it's really not, especially if you have a loud motor. My engine has always been very clack-y so I've never been able to tell what's actually pinging and what's just normal valvetrain noise.

That said, if you can figure it out, that is probably the best way to dial it in. I just can't figure it out so I don't do it that way.
 

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You would know it if you heard it, Kelly. You can actually feel it too.
 

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Pinging was a mystery sound for me for awhile. To me, pinging sounds more like what I would call "valve clatter". The valves are rattling or clattering when the engine is under load. When you hear it, you will know it's not right.
 
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