Sounds like you are right in the ballpark with fuel/air ratio. You’re supercharged but running conventional side plate intakes correct? All the Powersport engines were p-port which really does help power. 14:7 really SHOULD produce the highest egt. We were seeing 1600 regularly or a bit more. Running best power on the p-ports frequently produced 1650 or more. This didn’t cause any problems except shielding the exhaust was needed when running the engine in the conventional orientation. (NOT plugs up) Bill Bill, I”m not exactly sure what F/A ratio made peak EGT but was close to 14:7. Best power was about 13:4 to 13:6. Best power produced lower EGT than operating at 14:7 but would not keep EGT under my 1600F target above 6000 rpm. Mixtures leaner than 15:8 seemed to slow airspeed more than fuel burn. I would see EGT of 1550-1575F at this mixture. This is around 30” MP. Lower MP would lower EGT. Bypassing the super charger at altitude would produce EGT in the 1480-1500 range. But at a considerable speed reduction.
The turbo swap never happened. To many years of working away from home and the hanger is an hour each way. The Rans S21 caught my eye and I was ready for a smaller airplane. I wanted a plane that would allow me to remove the doors and cruise around at low speed and still be used for x-country. The S21 stalls at 40 mph and cruise at 154 mph true with the Titan 180 hp engine. The renesis should be similar.
Bobby Hi Bobby, I understand you have considerable time with your engine. I'm surprised at the A/F ratio. I'm passing along the info I have received from the original Powersport guys. Of course you are supercharged right? Or did you convert to turbo? The Powersport (original) guys were always NA. Steve told me that rich of peak was just rich of stoichiometric at about 13:1. Lean of peak could go to 16:1 or more. It of course isn't an apples to apples comparison with the engine supercharged. Just an FYI comment. With the intake air heated it would certainly skew the reading.
Bill Bill,
These setting worked best for me. I did my 8-10 hour days between Texas, Delaware, Ohio, etc with a lot of time to experiment. Of course takeoff F/A was in the 12’s and water injection at 38-40” MP unless it was really cold. No heat exchanger for the super charger. EGT under 1600F and intake temp under 140F were my targets. 93 octane usually with alcohol or 100LL.
Bobby Sent from my iPad Bobby, unless you have too much timing lead or exceptionally crappy gas it is unusual to detonate. That air/fuel ratio is rather bad place. Lean more or run rich of peak. Bill My preferred cruise economy settings 30” MP, 4800-5200 rpm. F/A 15:8 lean. Or 30-34” MP, 5200-5400 rpm F/A 14:0 or whatever was need to keep EGT below 1600F and intake air temp below 140F. Bobby From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net]
Sent: Friday, July 17, 2020 7:10 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] over square and detonation of a rotary for my pilot friend Hi people.
My test pilot friend and I are continuing our journey of extending the phase#1 envelope and now experimenting with engine settings.
With a flight adjustable prop he is asking questions about 'over square' and detonation.
Can anyone give me an answer for him?
Thanks
Steve Izett
Glasaie Super IIRG Renesis 4 port RD1C variable pitch prop.
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