Thread: Tuning a 302 Ford

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I have a low mile 1970 302 that probably has too much compression to run that regular grade crappy gas we have to deal with but want to run it any way,it did have any pinging untill I put on a 4 bbl and it showed up and when I put on a duraspark electronic ignition its worse. The car has a set of shorty headers and 2 1/4 inch duals so its probably way too lean as the plugs are white and it looks like I will have to deal with the lean situation before I do anything else,it has a 625ish CFM AFB on it now but I know nothing about tuning them so I will be looking to get a holley 600 since I have plenty of extra jets. Would putting stronger advance springs keep the distributor from advancing too much as its setup for a smog motor with a EGR and mine does not have that junk,I need some advice on tuning it to run right and for the best gas mileage. Jeff

If you have white insulators on the plug, you are for sure too lean. This is a major contributing factor to pinging - not enough gasoline in the fuel/air charge, leading to too fast a burn rate which is the ping. The DuraSpark just make a better and cleaner spark source - though you do need to open the plug gap and maybe go a step cooler. The AFB's are really Edelbrocks in disguise and most if not all of their tuning kit will work, regardless of the fact that E-brock says it was 'modified by Weber'. But, if you have lots of Holley parts, then change it out. A generally stock 302 only needs about 525cfm or less!!

Originally Posted by IC2

If you have white insulators on the plug, you are for sure too lean. This is a major contributing factor to pinging - not enough gasoline in the fuel/air charge, leading to too fast a burn rate which is the ping. The DuraSpark just make a better and cleaner spark source - though you do need to open the plug gap and maybe go a step cooler. The AFB's are really Edelbrocks in disguise and most if not all of their tuning kit will work, regardless of the fact that E-brock says it was 'modified by Weber'. But, if you have lots of Holley parts, then change it out. A generally stock 302 only needs about 525cfm or less!!

Run 10 deg initial. start wth 62's in the carb & an 8.5 power valve. When you changed to the durasparkII, did you open the plugs up. You need to run 'em at .045 - .050 to get the advantage of the DII bigger spark.

IC2 is correct. if you look any of the formulas for determining carb size, a 302 at about 85% VE, max rpm of 5500 will need a 408 cfm carb. All the more reason for me to go out & get a 390 holley & see what i can do

I did open the plug gap to .045 and it does have a edelbrock performer dual plane intake,I did pick up a holley 600 CFM carb tonight and will put it on next week and run it for awhile and see how the plugs are burning. I am going to take the duraspark distributor to a local to recurve it before putting it back in as I had to put the points distributor back in as it pinged too much with the duraspark. I figured since it was a 70 motor it had the stright up cam gear and it does still have the original 70 cam since it only 16,000 original miles and seen no reason to change anything. Jeff