Come on
rv6ejguy said:
The oil issue is no big deal in the Wankel. Just add your oil prior to fueling. No different than using TCP in a Sube or Lycoming. Just don't forget! (Add to preflight checklist). It's a pretty good Lyc that only burns 1 qt. every 16 hours. The ones I fly are more in the 4-8 hours per qt. The Wankels I have worked use nowhere near this amount of oil.
As discussed previously, Crook and others are reporting fuel flows pretty close to Lycs when aggressively leaned using his ECUs. Crook appears to be a straight shooter but it would be best to verify these claims with a head to head at Van's under controlled conditions.
TCP? Why would I use that? I never have used that and I was a flight instructor in a fleet of 35 plus aircraft, most with Lycoming engines. Lead fowling in a typical (higher compression) O-320/360 today is a non-issue, as long as the pilot leans the engine properly on the ground.
Yes 16 qts an hour, what are you saying I am lying?
robertahegy said:
I put 8 quarts in with a new filter on my 0-360. Half a quart (or more) goes in the filter leaving 7.5 (or less) in the sump. I go 25 hrs without having to add. I use about 1 qt in 25. Very little gets on the belly.
OneTwoSierra said:
I've put 8 qts in the last 2 oil changes in my 0-320 with oil screen only. The oil drops to 7.5 quarts rather quickly (4 or 5 hours) and then slowly burns another 1/2 qt over the next 20 hours. I'm going to stop wasting that quart and go with 7 and see what she does. I appreciate all the discussion on this topic.
If your Lycoming is burning a qt every 4-8 hrs , you have worn valve guides, rings or both? My twin with 2150hrs used less than 1qt in 8 hrs, which is after 2150 hours. My RV-4 used about 16-18qts/hr. With the new cylinder materials, Nickel-Carbide and thru hardened jugs, oil use has been lowered even more (read above).
Adding oil or any additive is a pain in the backside and you have to do it every time you add gas with the Rotary. I asked Tracy Crook about this. I forgot the oil use but it was significant, like a 3/4qt per fill up, which is about 1qt every 4 hours. Rotary uses more oil than a Lycoming, because it needs oil in the fuel to lube the seals, like a two-stroke engine! I mean it is not big deal and you don't have to be defensive and throw some useless Lycoming number out like a qt in 4 hrs. I mean it is just a fact and you don't have to attack a Lycoming to justify it. It is just the way it is. Every time you fill up you have to break out the bottle of oil to put in the tank. Lycoming might go several fill ups before getting the bottle out. Some are going oil change to oil change with out adding oil to their Lyc. Yes you check it, but that is little effort compared to adding oil. If it is not big deal to you, than great, Mo-power-to-ya. I hate it. I flew Cessna Citations Jets. When uplifting Jet-A I had to add the anti-ice called Prist to the fuel in a little spray-can.
This thread was started to discuss the Powersport, not attack Lycoming with exaggerated claims. When faced with facts like the RVator article I hear excuses and attacks. I can't understand why you have to justify the fact a rotary is thirsty, loud and uses oil. If you have data that is well documented, than just present that with out all the pot shots and defensive attitude. If you want a Wankel get one, but be realistic, it has limitations. Don't be so insecure you feel you must justify your choice in engine by tearing down the prime engine used in most aircraft. Don't justify the limitations of the Wankel, embrace them. There is a reason Mazda is the only one making a rotary engine car. They burn more gas. That fuel burn is justified in a hot sports car and may be an airplane. FACE THE FACTS:
THE ROTARY ENGINE RV-8 IN A FLY OFF AGIANST A LYCOMING POWERED RV-8 BURNED 34% MORE FUEL WITH AN ADVANTAGE OF 3-4 MPH.
I think that is pretty good. However when Tracy wants to race my RV-7 180HP Lyc, 4into1, dual EI, NASA/Lopresti/SamJames style cowl. Bring it. I know power sport engines are modified to make more power than the near Stock 13B Tracy uses. Again go slow, leaned out=Better fuel burn; GO fast, rich=High fuel burn. Apples and Apples. In the end the only way to get efficency is fly high, which applies to the Lycoming or any engine. This is as much or more from aerodynamics of flight and lift/drag relation of the airframe as it has to do anything with the engine.
Lets have a Cross country side by side fly off between Tracy's RV-4 and a RV-4 with Lycoming. Than we can see who is burning more fuel. Even a Lycoming with fuel injection can run lean of peak and get real low fuel burn, at the expense of speed. Again, lets o this. ANY RV-4's pilots with a IO-320 out there want to do this? I say IO-320 because Tracy's RV-4 is as fast as a fast 160HP Lyc powered RV, however a IO360 would work to. Tracy raced in the 160hp class lastat Sun-in-fun but claims it makes 180hp?
Fuel burn? Facts, how fast was Tracy going in this super lean mode. I have flown my RV-4 to 17,500 and got fuel burn down below 5.25gal/hr and still had TAS of +165MPH (that was a O320 150HP Lyc). When you open up a Wankel (race mode) it will drink fuel at a higher rate. I like how you ignore the RVator article and divert the rhetoric to Tracy and his ECI can go into super lean mode. Look Apples and Apples. You want power you burn gas. Wankel will burn more than the equivalent piston Lycoming producing the same thrust. Deal with it. You can mitigate this weakness but you can't eliminate it. You want to dream of super efficient super Lean mode go ahead. Accept it or continue to be delusional. People don't fly "Super Lean". Tracy's own test on a new rotary engine produce eye watering fuel burns (17gal/hr) or something like that. Again the experts agree that the physics of combustion in a rotary engine has inherent inefficiencies. I know I am blaspheming on the alter of rotary, but it is true.
As far as noise, prove a turbo makes the rotary quite. Facts, numbers, test. I don't care I love engine noise, including a rotary. Again from the RVator:
DURING THE RV-8 FLY OFF THE ROTARY POWERED RV-8 GOT THE ATTENTION OF THE AIRPORT AUTHORITIES!
G