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Are their any formulas and/or techniques which can be used to determine what the ideal distributor advance curve should be? Or is it one of those things derived by trial and error?

Thanks in advance,

Dan
 

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My vacuum advance was originally set up by trial and error. I have since installed an MSD Engine Knock Alert. (Which is a VERY powerful tool!!). You will need an adjustable vacuum advance. I use one of the old Crane units. You can also shim the spring in or out on the stock dizzy. I use a recurved stock dizzy with an MSD box. If you do not have the Knock Alert,use the following routine which is quite accurate. With everything warmed up and the initial set where you prefer (I am running 16 deg. initial) run at a constant reasonable cruise speed on a level road. (A slight up-grade is OK). Quickly and SLIGHTLY give it a bit extra throttle. You should get a SLIGHT ping. If not, adjust the spring tension around (up or down) until you have a barely audible rattle. Incidentally, I use full manifold vacuum. There are many opinions on this. I find using full manifold vacuum works best for ME. She runs like stink and gets 22-23 MPG at 75 MPH. If you have the Knock Alert, the process is very accurate and easy. Being older, I can't hear the ping frequency (approx. 15 KHZ) very well. The Knock Alert does this for me. Take your time. The final results are worth the effort. Best regards. John---Las Vegas.
 

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Here is a great article from Ford Muscle. Should be all the detail you'll need.
 

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If you don't want to have it profssionally curved it's gonna take some trial and error. I spent $25.00 on my kit and played with it until I was happy. I'd read the instructinos that come with the kit as well as the article that Mike cited (I have the same article) and then have at it. I borrowed a dial back timing light so I could get close with fewer tries........
 
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