Chippy and I have had some great acro practice flights over the past couple of weeks! Getting ready for the airshow and competition season at last. Thanks to Lycoming Thunderbolt for the new 280+ HP engine, and Electroair and Smooth Power for a terrific electronic ignition! The engine starts easily and runs smooth and powerful for aerobatics.
Today I think I finally resolved a long standing issue with the old engine, that reappeared with the new engine! Both squeezed out oil here and there, including from the crankshaft seal making for a messy airplane. It was worse after flights with lots of time inverted (the best place to be!). I’ve long suspected high crankcase pressures: during the rebuild in 2009-2014, I used a method common on aerobatic airplanes to port crankcase breather gases via a 3/4″ pipe through the fuselage and out the tail. Usually this is neat and tidy – the oily mess goes out the tail (or on someone’s ramp!) But with Chippy, the gases seemed to back up in the crankcase. Nowhere for it to go except out the seals. When the new engine developed the same symptoms after flying aerobatics, I knew I needed a solution!
So I installed a system called Anti-Splat (love it!) that ports the crankcase breather gases to one of the exhaust pipes instead of out the tail. A hose connects the Christen inverted oil system breather to a Venturi tube inserted into the exhaust pipe. The idea is that the Venturi creates a LOW pressure instead of high pressure in the crankcase. Magic, no more oil squeezing out from every pore. It also claims to increase power a little by helping to draw in induction air and suck out the exhaust gases. I dunno if that’s real. But I do know that after a long flight of continuous aerobatics, with lots of time upside down…. I came home with a clean engine! Whoo Hoo!