Ignition cap and rotor "aging"

[PierreW]

General thoughts on the aging of distributor caps and rotors: aside from the (natural?) degradation of the poor-quality materials used in manufacturing (likely Chinese?) aftermarket parts, there is an oxidation phenomenon affecting original components caused by ozone formation as the spark jumps between the spark plug wire terminals and the rotor contact. Ozone (O3) is highly oxidizing to synthetic materials; add moisture under the cap to the mix, and you have the perfect recipe for ignition misfires :-) — even with high-quality parts! I routinely spray silicone fluid or better silicon grease on the rotor and inside the cap (after removing them, so as not to contaminate the breaker points!); in 50 years, I haven't had any ignition issues stemming from this.