I do not think it is the torque converter, my pinging goes away on premium gas, carbon deposits in the intake manifold should not cause pinging, but they do rob power though by restricting air flow.
More advanced timing makes it more likely to detonate than less advance. But I would not set the timing to any less than the stock three degrees before top dead center, if you are already at stock then move on to something else.
Higher intake air temperatures make it more likely to detonate than lower intake temperatures, so summertime or other hot conditions you are more likely to detonate than in cool or cold weather, a snorkel or any other cold air intake helps here. The sock intake gets its air indirectly from the engine bay, OBDII reports have seen 30 degree drops in air intake temperature when a cold air intake is used, also a supercharger or turbocharger will drastically increase intake air temperature, an intercooler helps with this on forced induction engines.
At higher altitudes you are less likely to detonate than at lower altitudes
It is more likely to detonate with higher intake manifold pressure than lower, so the more skinny pedal the more likely it is to detonate, forced induction can increase intake manifold pressure higher still per throttle opening and can go above ambient (boost).
Lower octane gas is more likely to detonate than higher octane gas,
Higher compression ratios are more likely to detonate than lower compression ratios, shaving the head or block increases compression ratio. Also excess carbon on piston tops and the bottom of the head can increase compression ratio my decreasing combustion chamber volume. From all the heads that have been off we know that this motor likes to build up carbon, I think excessive carbon build up is an unfortunate side effect of an engine that lasts a long time. Large amounts of funk form the PCV and EGR to not help.
At higher general engine temperatures it is more likely to detonate than at lower temperatures. Overheating even if mild can lead to detonation, check your cooling system.
Higher engine loads can cause detonation,
Fuel cools, leaner mixtures or mixtures that does not atomize well will make it more likely to detonate so slow responding O2 sensors and poor fuel injector spray patterns can cause detonation.
Several instances of any of the above add up, So if you have pinging pick these off one at a time until you fix the ping,
basically what this all boils down to is the temperature and pressure of the intake charge the condition of the cylinder (hot spots carbon etc) as the piston approaches top dead center between the compression and power stroke, if that temperature and pressure go above what the fuel can resist the charge will ignite on its own before the spark,
There are supposedly differences between pre-ignition and detonation, they are related and both cause a ping to be heard, both shorten engine life and come from the same kinds things so I personally don’t really differentiate between the two,
here is my engines story, when I got my 80 I advanced the timing got a notable increase in power, I was using premium gas at the time, no pinging summer or winter for 2 years and about 50K miles. No problems, recently with the sharp increase in gas prices and a matching decrease in my income I tried running regular and mid grade I get pining during acceleration in both, but more so with regular especially in hotter weather, pulling away from a light in heavy Atlanta traffic after idling a long time with the AC on seams to do it every time. same with a fast food drive through.
I put the timing back to stock 3 degrees hoping to be able to run regular without ping, it helped slightly but it needs more, I know from compression testes and by looking with a bore scope that my cylinders have rather high carbon build up, this is probably my biggest problem, high temperatures here in GA add to the problem.
I use good gas and have used the dump in the gas type cleaners (Techron, Redline) , they can clean up dirty injectors and maybe have an effect on the intake valves and intake pockets in the head but seam to do nothing for the cylinders, considering limited funds I think next step will be a decarbonizes using water see if that helps, that or give up and just run premium until the head comes off.
