Archive for October, 2014

12.1 Hrs in Phase 1

October 26, 2014 Leave a comment

Sunday Oct 26, 2014

I’ve been out of town almost two weeks so I missed flying last weekend. I did get a flight in this weekend and did a couple of stalls. The Hobbs meter is now up to 12. 1 hrs so I am nearing 1/3 of the way through Phase 1. Sunday was a day for maintenance and no flying. It was about time to replace the oil and filter since the engine is probably broken in by now. I also had a tiny leak of oil around the sump drain plug that I needed to fix. It was just a tiny seep but it would drip down onto the inside of the cowling and leave a trail. The removal of the drain plug and the reinstallation with Permatex #2 went smoothly but I had a heck of a time getting the oil filter off. It was installed to the specified torque (18 ft-lbs) but it took a lot more than that to get it off. The 1-inch hex on the end of the oil filter actually broke off so I had to use strap wrenches to get it off. In fact I broke three different strap wrenches in the process. After about two hours of struggling I finally got it off with the help of two friends at the airport. Rest assured, the new filter was installed with lower torque and the rubber seal was well oiled. The photo below shows the drain plug reinstalled and safety wired. After refilling the crankcase with oil I ran the engine for a few minutes to verify there are no leaks, then I safety wired the new filter.


I also installed a new cooling air blast tube to the mechanical fuel pump. This is to address my rough hot idle problems although I doubt it will make a big difference. But it is a simple add-on so I will give it a try. The new tube is seen in this photo on the far right of the aft baffle.


This photo shows the tube as it routes down past the engine mount bushing toward the mechanical fuel pump.


And this photo shows the tube secured to the pump with two adel clamps so the air will blow on the side of the pump housing. If this doesn’t fix the problem and I will replace the fuel injector nozzles with the next smaller size and see if that helps.  



Categories: Flying

9.5 Hours in Phase 1

October 5, 2014 3 comments

Sunday Oct 5, 2014

Today I hit 9.5 hours on the Hobbs in the Phase 1 flight test program. Mostly I am still breaking in the engine so I run at 65 – 75% power and keep the engine rich to make sure cylinder head temperatures don’t get too high. One of the tools I am using to monitor things is the engine sensors on the Dynon display. Here is a screen shot taken today while cruising in the flight test box at 75% power. As you can see the engine is at 2500 rpm, true airspeed is 147 knots, and the density altitude is 8573 feet. I would prefer to test down lower but the terrain altitude is over 3000 ft MSL so I was flying at 6300 MSL. Fuel flow is 12.9 gal/hr and the peak CHT is 402 F which is just rising above my yellow limit of 400 F which is conservative. You can also see from the display that I had the autopilot on Level mode. It’s great to be able to take these snapshots anytime I want by just pressing two buttons.


I also use SavvyAnalysis to analyze EFIS data logs which I download after each flight. This is a free tool that plots the key EMS data for the entire flight. You can spend hours reviewing the data and gaining a deep understanding of how the engine is running. This plot shows true airspeed on top and all four CHTs on bottom. It is easy to switch parameters of either plot to show EGT, GPS altitude, fuel flow, amps, oil pressure, oil temp, or a host of other parameters. Very cool capability and it makes flight test easy because I don’t have to write down data while flying.


Categories: Uncategorized