Plug oiling without burning much oil

[Alan South]

I am suffering frequent plug fouling problems. The cause is oil, not lead, and the oil can be burned off in an extended run up.

However, the engine is not burning a lot of oil. It uses about 3 quarts between 50hr checks, a consumption of about 0.06 quarts/hr. Lycoming state the limit is 0.55 quarts/hr. The engines are two IO-320s. Quite a lot of my flying is 7-10,000' at about 65% set at peak EGT

I have a couple of theories, but first would like to hear if anyone else has any ideas.

As an experiment, I have changed the lower plugs on one engine to fine wire plugs.

Thanks in advance

Alan