Broken crankshaft out of my Corvair 2700 with 160 flight hours. A contributing factor may have been the deer strike I had back on May 15th. I did not take the engine apart then to magnaflux the crank so the true cause is pure speculation. Personally, I had been feeling minor vibration prior to the deer strike. Anyway, I was crusing at 4,500' over Clintonville, WI on 8-16-2008 when the crank broke. Fortunately, I made a safe landing at CLI.