Lycoming Engines will release Service Instruction SI-1070S in the fall, which will add 20 engines to the list of models approved for use on UL 91 unleaded avgas and bringing the total number approved to 55. With the move, Lycoming officials continue to call for UL100 as a fleetwide solution to replacing 100LL.
Q: I have a Lycoming IO-360-A1A on a Mooney E model. My mechanic tells me that there are two timing settings for this engine: 20° and 25° BTC. The engine had been set at 20° BTC and he reset it at 25° BTC. What are the advantages or disadvantages of this timing change? The engine is running slightly warmer and appears to be a bit louder in the cockpit.
DAVID WALKER, via email
Q: I have an O-290-D2 that I am going to use in an Experimental Wag Aero 2+2 that I am building. Although the engine was flying regularly before I removed it from a Pacer and pickled it, I want to open it up to look at the cam. If the cam is pitted, a replacement will be difficult or prohibitively expensive.
Lycoming Engines has applied for approval to use UL 91 unleaded avgas in several of its engine models, including those in the 233, 235, 320 and 360 engine families. Engines in the 540 family will follow as Lycoming completes additional validation, Lycoming officials said.
Q: I recently found paper towel bits and pieces in a Lycoming engine in an aerobatic airplane. The pilot said he saw the oil pressure go to “zero,” so he reduced power, and landed safely. Would you suggest a flush or overhaul? What’s the best way to go about this?
ED NELSON, via email
Q: I have been noticing an intermittent miss on the left mag during mag checks on the O-235L2C in my 1981 Cessna 152 (about 670 SMOH that included new Lycoming cylinders and pistons). About 30 hours ago when I cleaned, regapped, and rotated the plugs, I found that the lower plug on the #4 cylinder was filled with oil around the inner electrode and ceramic insulator. [Read more...]