1964 390 Pinging

[phillip6412]

I own a 1964 T-Bird 390 and have replace the spark plugs, wires, points/resistor, cap and rotor. I still have some pinging when accellerating even after checking and re-checking the ignition timming.

I am currently using 90 octane (non oxygenated fuel) and am wondering if I shoud ditch the timming light and just tune it the old school way or do I possibly need an octane booster?

The pinging only occurs after the car is warmed up.......

[Ken(Ark)]

I have a truck that does the same .

If I buy premium gas it does not ping , try a tank of premium or a bottle of octane booster and see if that stops the problem . At least you will know where you are at .

I ended up retarding the timing to stop the ping while using the cheap gas , yes I believe its cheaper than they state on the pump decal .

My take off power is terrible but I have learned to live with it .

[phillip6412]

Thanks for the information, I will see if I can get time to play with it this weekend (weather permitting).

[Liveaxle]

Is the motor original? No modes or work done? Could be a lot of things, but when timings an issue check the balancer for shift due to old rubber. It might give you a false reading. Check the distributor assembly-springs, vacuum advance n such. The stuff does, even though it's well built, wear out. Maybe this will help.

[kennykencan]

Did you solve your pinging problem?

If you got your timing set the best you can either by light or ear and its still pinging, try using octane booster.

If octane booster works for you and you want to save some money, go to a Sherwin Williams Paint Store and purchase yourself a gallon of Toluene for ruffly $8/gallon. Add 32oz to each tank of 93 octane premium gas, and the result will be 95 octane gas. Add 64oz will bring the octane up to about 98 Octane.

Don't worry about using Toluene because the gas companies have already added this as an additive to bring the octane up to where they want it.

If you can't find Toluene, you can also use Xylene, also available at Sherwin Williams. Home Depot or Lowes. Sherwin Williams is usually cheaper/gallon.

These engines where designed to run on 100 octane fuel with their 9.5:1 or 10:1 compression ratios and by adding Toluene or Xylene will raise the octane of premium pump gas close to what your engine really wants.

[lazy390]

Hi ya
Another reason they ping is because of wear in the the main butterfly shaft on the carb.As they wear the engine draws air through the shaft and leans out the mixture, not easy to fix as you need to have them drilled out and sleeves fitted. Grab the throttle on the carb and if it moves up and down there is too much play and excess air will be drawn through it...hope i helps