Oh no, "Come on, be fair"? OK
GMC-
Come on, be fair. Tracy ran in the 160hp class because that is what that engine produced with marginally-effective motorcycle carbs early in the development process. Mazda rated that same motor at 140hp in autos. Tracy and others easily get 180 with his current FI system.
OK you're a rotary fan. I get it. I think rotaries are COOL, OK. I drove several rotary mazda's in the 70's. I don't want an argument but, come on, be real. When Tracy won in the 160hp class one year, that was something to be proud of, but don't tell me its a 180 or 200hp of equiv Lyc thrust, excuses not withstanding.
No offense but there's always an excuse for rotary performance, high fuel burn & loud exhaust bark. I've heard excuses for 10 yrs (really 20 yrs). There are always breakthrough's that will fix it. First, the Carb excuse, than the Fuel Injection's "mapping is not proper". I've heard it all before. I did not mention Tracy by name. He and his wife are super straight honest (and vary nice) folks. I like his approach & products. However any enthusiast is, well enthusiastic. I reject fuel injection is a panacea of HP or fuel economy on a Rotary (or any engine). Carb or FI on the same LYC does not change HP, at all (well may be 1%). People get confused with the 200HP IO360 angle-valve. Higher compression and different heads makes the extra 20HP, not FI. Yes FI can save fuel on a LYC, about 2% or 3% if you lean carefully, more for LOP ops may be. All I'm saying is
Tracy competes in 160HP class and still does, and that was recently, I believe post motorcycle carbs.
FWIW, the output in a rotary is dependent on rpm, which is mostly a function of intake system capability. Current systems with the same engine BUT with FI and intakes tuned for ~6000rpm produce 180-200 hp, a bit more ~250 with peripheral porting, up to 300 with turbocharging.
Oh BOY here we go.
Again I don't want to be disagreeable, but NO. The super custom, expensive defunct Power Sport rotaries (which I admired) where not stock 13B's by any means. They matched a 180hp Lyc's performance (which is great) but at the expense of massive extra fuel flow. Power Sport rated them @ 210HP. Tracy even warns not push HP too far above stock for reliable power. 6,000 rpm! Wow? It's working hard while the Lyc is chugging along to make the same power.
Van's fly-off was between stock factory prototype RV-8's w/ Lycs & two Power Sport RV-8's. The results where published in the RVator, facts meet the fan, real-world-side-by-fly-off data. The RV-8's w/ Power Sports IMHO where the best of the bred, w/ nice aerodynamic cowls & cooling system. The Rotary RV-8's (btw one later crashed due to an electrical problem) are better than a typical roll-your-own stock 13B, in my opinion. Nothing wrong w/ a stock 13B + RWS parts and it's a bargain compared to Power Sport's $40,000? A RWS setup is half or less. Still the Power Sport planes where beauties, but they where heavier & louder (as measured by dB meters). The killer was FF, 13gal/hr verses the Lyc's 9gal/hr, while doing the same thing in the air. OUCH! All factual & no bull. Still the Power Sport 8's turned in impressive & respectful performance. I hope they come back.
Excuses & rationalizations where made about the Power Sport RV-8's fuel burned. The FI was not tuned or something? The fact is rotaries are just fuel hungry, always have & always will be. This is consistent w/ rotary Mazda's on wheels, lousy gas millage, but a Porsche 911 does as well. You can't complain about 18-20 mpg, its a sports car not a Prius. A RV is a sport plane.
"but a Lyc is made to run at 2,700 RPM all day long" ...BS FLAG, or at least misleading!
No, it's true not Bee Ess. Let me rephrase, there's no Lyc restriction (time or otherwise) on 100% power or 2,700 RPM (unless the prop's restricted), period, end O-story. Lycs are build like fort knox's.
2700 is relatively slow rpm; but a Lyc might, or might not, be producing full rated power depending on the situation, prop, etc. Lyc claims peak hp numbers that might be achievable under perfect conditions, everyone knows that a Lyc will not last at full power for extended periods of time in the real world, particularly when leaned- they recommend use around 60% of peak hp most the time, don't they?
NO NOT PERFECT, NORMAL CONDITIONS!
First, the air-box & pipe's for Lycs in RV's are effiecent, making rated power or more w/ out question @ sea level atmo, std day & 2,700 RPM. YES, you're right 2,700 RPM may not be 100% power, if MAP is less than 29" (such as flying at altitude). Pwr may not be 100% on takeoff with a fixed prop, which does not allow full RPM. This applies to any engines, but auto engines can take a bigger hit with fixed props and poor induction/exhaust pipes.
To be CLEAR:
Lycs have NO limits on making 100% HP. Lycs can and do routinely make 100% pwr unless there's weird induction/exhaust restrictions, which is not the case with most RV's. Fact most LYCS in RV's are capable of making more power than stock, not less. They are quasi de-rated, conservatively. Lycs have another advantage, many custom "hot rod" parts for induction, exhaust, ignition, with many vendors. There are three "Lyc" engine vendors as well. Alternative engine guys don't have this.
Flying into less dense air does reduce HP, but that applies to any ATMO engine. However less air density reduces cooling at altitude, which is a problem for turbo/blown engines, which can run hot at altitude. HP does not reduce with altitude but cooling does which is a problem with the supercharged Subie.
I've raced my RV-4 several time, wide open throttle, on the deck, 2750 RPM, all day. Temps where in the green. It's totally fine, ask Lyc engineering, no restrictions on 100% pwr. Lyc does recommend 75% for max engine life. Some Lycs double TBO.
You mention PROPS. Another advantage of Lycs, they have hydraulic constant speed prop capability; most alternative engines have fixed or a less desirable electric wood/glass props, which are not as efficient as a metal props (BA Hartzell or Sensenich-fixed). Prop selection is another reason alternative engines are ham strung, low efficiency props. The LYC is a low RPM torque engine which can even "pull" a fixed prop on takeoff. A fixed prop on a Subie or Mazda will be hurt more on takeoff & climb than on a Lyc. MT blades are not as efficient as a metal BA hartzell.
The rotaries can hum leaned, at rated power (5000-7000 rpm), as long as you want, with minimal wear and no fear of damage.
OK that's good, because rotary engines are so fuel inefficient, they need to lean aggressively. Wankel's drink gasoline like a sailor drinks booze on shore leave. A Lyc can be leaned w/ out restriction at 75% pwr and is still more fuel efficient, even at full rich power than a rotary leaned.
I agree with your comments as far as most reciprocating engines (ie, Subi and Chev, even Lycs) motors are concerned, the Suzuki is probably an exception- designed for continuous 5000 rpm freeway cruise. The internal stress rises (exponentially?) in a reciprocating engine as rpm increases- think of the mechanical stress involved with the pistons/rods pounding (accelerating and stopping) with each rotation of the crankshaft, particularly with large bore (Lyc) engines.
Lycs are designed for airplanes, to directly drive a prop in the 2,200-2,700 RPM ball park. The 2,700rpm RED LINE is conservative, by design not weakness. A Lyc can turn faster but does not need to. There's no Lyc time or stress limit on making 100% HP. I can fly 100% power all day long or 2,700 RPM. In the winter its easy to make more than 100% w/ dense air.
Lycs are not WORKING or breathing hard at rated pwr; they're under-tuned, under-stressed for reliability. They chug along at 75% or 100% rated power, as designed.
