Bob,
Without breaking down the engine, and just doing a compression check, it appears that we have 78 at the top of the cylinder rise, and 30 with air hissing into the crankcase, which we can hear through the oil filler tube. No noise at the exhaust. this is #4.
I was flying home from Mexico, on a trip with Aeromedicos. A friend was teaching me the procedures for crossing the border. Left Mexico with just over 7 quarts of oil, and about 80 pounds of pressure on the gauge. Had to make 2 stops, one to check out with the Mexican government, and one to check in with homeland security, which we did in Calexico. Left Calexico with full tanks, and the same reading on the oil pressure gauge. We encountered pretty high head winds on the way home, about 26 knots average, and the plane was making 110 knots ground speed on all the GPSes. We came over the clouds at about 8500 feet, and when I got over the Pacific, the clouds were gone, and I tried lower elevation for better speed. At Catalina island I noticed that the oil pressure had dropped a little but that is not unusual in my plane. After 5 hours of flying, some oil is burned and there is a slight drop, but the needle is far into the green. Into Santa Barbara, I was told that due to the winds, only runway 25 was in use and there were planes holding, and on the ground waiting. I was told to get comfortable, and to start 360's for spacing, that I was number 5.
I started to go to the right, and once comfortable with were I was, offshore about 10 miles to the airport, just outside the harbor of Santa Barbara, I began descending 360's to the left, which are easier for me. Within the first 90 degrees, I looked down and the oil pressure gauge was pegged on the redline. I called approach, declared an emergency, and put the plane in a slow descent and straight line for the airport. I did remain off shore, I figured if I lost the engine, It would be easier to put in down in shallow water, than into someone's house. Approach, informed the tower, and I was immediately cleared to the runway, and made a very quick descent and landed. When I turned off the runway I was going to shut down, pulled the power back to idle, and the oil gauge came back to the top of the yellow. I decided to taxi, in and when I got to my parking space my A&P was waiting. After answering all fire and security questions, we pulled the dip stick. It was wet, but registered barely anything.
No oil on the belly, engine compartment dry. Went out the next morning, and the dipstick measured 3 quarts. I read low, so we figured it might be 3.5.
Rick