Source: 2013 Q1 Beartracks, Merv Hargraves
After having some trouble with the old Continental O-470 APU engine, I decided to bite the bullet and replace it with a new Lycoming IO-390 and Constant speed Hartzell propeller. The old engine had about 440 hours in the Bearhawk, and although I had a pretty good run, it was thirsty if run with much power and seemed to forever have oil leaks. The reasons for the engine change were to hopefully reduce problems and to decrease fuel consumption. This worked out great with also a reduction in empty weight, so much that I was able to install extra fuel tanks, update the panel, and still lose 45 lb. My new panel included a Dynon D180 with autopilot servos and backup battery. The old prop was an Ivo 3 blade, which was a lot lighter than the Hartzell.
This upgrade was completed only shortly before my trip with some mates and their wives around Australia. The trip covered some 5800 nautical miles over 28 days with a total of 55 engine hours and 50 flight hours. The aircraft performed great and fuel consumption averaged 35 litres per hour (9.25 gallons per hour). When the fuel was all full the load was near maximum, and the extra fuel was really worthwhile for this long trip.
With the new engine it performs probably a bit better than it did before and uses about 10 litres per hour (2.6 gallons) less fuel cruise at 118 knots (135 mph) than it did. This speed is what I consider my best performance/economy. It will cruise 125 KTAS but the extra fuel does not convert to extra miles. Climb was better than with the old engine mostly because of the prop I would say.
The new engine now has about 165 hours at the time of writing and the Bearhawk has a total of nearly 600 hours, I have had really no trouble with the airframe and this design is a great all around aircraft. A couple of weeks ago I had the fortune of following a C182R turbo on take off. We were going the same direction, and my Bearhawk was slightly better up to about 4000 feet. After 5000 ft the turbo helped him pull away. The Bearhawk was my first aircraft and so I had plenty of skills to learn along the way, and it was a great experience for me and an enormous joy when it finally flew. I have tried to get more Bearhawk builders out here but it seems to be slow. They don’t know what they’re missing! I really enjoy building, and I have built a Skybolt since the Bearhawk but have sold it. It was a lovely aircraft to fly but did not have the versatility of the Bearhawk. My next project might just be a Bearhawk LSA as light aircraft are very popular down here. Fuel is getting so expensive at $2.12 per LITRE for AVGAS (approximately $8 per gallon) and this might be good for later in life. Later this year I hope to see another Bearhawk flying down under as my friend Brad is well under way with his scratch built, with fuse and wings built and fabric all done and painting this week.