Tracy, just so we are on the same page, I assume you mean 175 MPH (not knots)? My data was taken between 10,500 and 12,500. It might be interesting to see what my fuel burn and MPG would be if I slowed it down to 175 MPH.
Tracy wrote:
About 30 mpg is what I currently see under best case conditions (12,500 - 14,500 MSL, 6.0 gph, 175 TAS). Interesting experiment on way back from Lumberton. 4 RVs departed for Florida Sunday AM, 3 Lyc powered and my rotary. The Lyc guys were taking too long to get packed up (I get antsy when I'm ready to go) so I left 15 minutes before they did and told them I would go slow and meet up on the way since we were flying the same flight plan. The Lyc guys flew at 8.5 GPH power setting and I flew at 6.0 GPH. Had head winds all the way but interesting part was that after 2.75 hr
and 370 miles after my takeoff, the Lycs caught up to me. The extra speed of those 2.5 GPH really does not buy much! And I got to spend more time in my beloved airplane : ) Fun & Relaxing trip & fly-in BTW. Tracy (must get Ed's Gin & tonic formula) Sent: Monday, May 22, 2006 12:33 PM Subject: [FlyRotary] 100LL plug fouling
Al Wick might have got some of his "100LL in rotary" comments from my experience. I can't burn 100LL, it will foul my leading spark plugs after only 4
hours. That is because my engine runs rich-best power all the time. Of course running rich results in a higher fuel burn too. These days I'm doing about 160 knots on 8.8gph, or 184 mph @ 21 mpg. Burning mogas all the time, my leading spark plugs still only last about 50 to 60 hours. Trailings always look better. My 1988 RX-7 with exactly the same engine gets about 18.5 mpg combined city/hwy driving, probably low 20s if it was continuous freeway. If I had lean control I would expect results more like Ed Anderson with regard to 100LL and plug fouling. I would like to see some fliers express fuel usage in mpg, an easy way to compare efficiencies. For example, Tracy and Ed leaning might see 25 to 30 mpg? |