I enjoyed a nice 1.2 hour flight yesterday, but ended with oil or exhaust smell. Never a good thing, conjuring up images of a fuel fire or carbon monoxide poisoning.

Today I gave it another routine cowl raising inspection, and noticed the usual oil film. It's everywhere, and comes from no-where. It was cooking off from the under slung muffler. I wiped it off, and I think the culprit is the crankcase vent from the oil fill tube. I had to shorten the tube so it would fit under the cowl. Now the vent line is pretty low, just over the center iron into which the oil tube fits. It discharges thru a tube and hose arrangement to the right side of the cowl outlet on the bottom. I think the airflow in this area is turbulent and sometimes back flows into the cowl and spreads all over.

I added another heat shield to keep the radiant glow of the exhaust system off of the fuel system.

I also noticed the throttle opened about 40 degrees shy of full open. So I adjusted the cable lock nuts to give more; however, the throttle is sufficiently oversized that it didn't make an appreciable difference.

After a joyful morning of small improvements and cleaning, I decided to make an hour flight, have some lunch and do a second hour flight.

Well, that was arrogant of me. I made it about 30 minutes and noticed the oil pressure had dropped from 62 or better to 38 PSI. Water & oil temps were in the 160F& 170F zone. So I headed for the nearest airport and slowed 'way down. The oil pressure increased to 39-42, so I eased it on home. Off with the cowl, oil checks full, everything on the outside of the engine looks good. I got a mechanical oil pressure gauge, and yes, 40 PSI at the oil filter housing, while reading 39 PSI on the Engine Monitor.

I'm stripping the 'front' cover off, expecting to find the famous oil O ring blown....Maybe I should have used larger diameter oil discharge hose...

The bolt that takes the 19mm socket on the pulley hub defeated me this evening. I hope it's not a left hand thread...I'll continue tomorrow.