Norman CYYJ
Well Known Member
Do any of you guys know of anyone with a 180hp engine in their 9. I would be interested to know what the numbers are like.(climb, speed and max altittude, speeds in the lower flight levels)
LifeofReiley said:I've been told the insurance companies are siding with Van's recommendation of 160 hp max for the RV9. This would be something you might want to look into unless you just have deep pockets.
Righty said:From what I hear, this airplane has plenty of performance with 160 hp. I think I saw a post by someone in Utah the other day where they said that the -9 was perfect for the high DA's.
Wow... very similar thoughts to what I have been wondering lately. It would be nice to have a "Van's 9.5" - and be able to carry a third person - ie: small adult, or maybe a couple children. I also like the idea of sticking with an O-360 vs. going to the -540. I don't need 200 mph. I'd like to have 160 mph/900fpm@6,000' at gross weight.63scrounger said:First: I agree with all those who say that 160 hp is the max and the ideal for the 9.
Second: The parallel valve 180 hp Lycoming has one of the best power to weight ratios. It is very reliable and easy to come by as well. It would be cool to have a 9 non-acro, cross-country cruiser type airplane that used the 180 hp engine and could carry two adults and a few kids. Just super-size it so to speak. What could we call it. The 9.5. Since it would be between the 9 and the 10. What do you think? Is there a demand for this?
cobra said:Jconard- I think you misquoted/misunderstood Crook.
snipped
To be fair, we need to add in propeller weight too. Hydraulic C/S props tend to be heavy. Im planning to use the comosite IVO magnum in-flight adjustable propeller @ 24.2 lbs (26.7 lbs for 3-blade version). The Lycs vibrate too much for this prop and are not recommended. This prop is rated up to 700hp and has worked well on other rotary and Subaru installations.
db1yg said:Bryan did you have a chance to get any performance data on your plane---I am interested in the results.
db
RV9a/ECI 0360/Catto Prop/James Cowl
Continous cruise flight at true airspeeds in the yellow arc is not a good practice.
Well, here it is 3 years later. This shot is taken at 8,500', full throttle, and the prop set at 2,300 rpm. (Pardin the dust. Look at the true, and then look at the yellow. "How many of those naut thingys are there still in this airframe before tickling that thar yeller part that'n wer s'posed to be afearin." This is why I felt like I got laid away by being convinced to put a dinky little sissy engine in my plane. When I was deciding there was no picture like this!
Sorry Brian, but your example is totally pointless in the context of why a smaller engine is specified for the RV-9. If your point had any merit, you could just as well show a photo of your airplane with built with 200 HP but flying at 14,500 full throttle and 2300 RPM. The IAS would still be well within the green. How about 260 HP at 17,000........I think you get my point.
If a designer is using FAR 23 as a guide line (not required in kit airplanes but it is a good idea) when designing an airplane, then they design for a Vno speed at the engines maximum continuous power. We all know that Lycoming has set that at 75% for most of their engines. If you look at the power chart in the operators manual for your engine I think you will find that when this photo was taken you were a bit short of 75% power.
The other thing you are missing is what your IAS would be at 75% power at 2000 MSL. In the case of an RV-9 with 180 HP flying at 2000MSL at 75% power, the IAS would be well into the yellow.
Scott, why is flying in the yellow a bad idea? The yellow ark (as far as I know) means damage can be caused from full deflection of control surfaces. Cruising in the yellow in smooth air is fine as long as you don't make abrupt stick or rudder input. You can fly up to VNE all day long on smooth air, just don't do a full pull on the stick, or remain in the yellow if you encounter moderate to sever turbulance. Yellow means "caution", not "don't do it", that is what VNE is for.
Airspeed Indicator Definitions
The airspeed indicator is connected to both the static ports and the pitot tube. The airspeed indicator is color-coded to help the pilot immediately recognize the important airspeeds and ranges of airspeed. The color codes are: White Arc, Green Arc, Yellow Arc, Red Radial Line, and Blue Radial Line.
White arc ? The white arc is the flap operating speed. The bottom of this white arc is VS0. VS0 is the power-off stalling speed with the gear and flaps down. Going up along the airspeed indicator we come to the Green Arc. VS1 is where the white arc meets the green arc, or is commonly referred to as the bottom of green arc, or the power-off stalling speed with gear and flaps up.
Green arc ? The Green Arc is the normal operating range. The very top of the green arc, is the maximum structural cruising speed, commonly known as VNO.
Yellow arc ? The yellow Arc is the caution range. The aircraft should not be flown in this speed range in rough air. The Yellow Arc extends from the top of the green arc to the red line.
Red radial line ? The Red Radial Line is the never-exceed speed, or VNE.
Van's spec's on the -9.... Performance Speed - Solo Weight Top Speed 197 mph
Blah, blah, blah... I could have spun he prop faster and gotten up to 75% but still couldn't have seen the yellow from there. Go back a couple of posts and read your own words. I put up a picture that supported what you stated. Then you want to argue about it? The challenge for anybody to post a picture of their airspeed indicator at 7,500' with all in has been something I've been challenging anybody arguing for a 160 hp max for years now. I'm running 170 hp and this is what it looks like. For each additional 100 rpms I get around 2 miles per hour up to around 2,600 rpm, but the fuel burn goes way up. Still, no stinkin yellow near the needle.
Well, here it is 3 years later. This shot is taken at 8,500', full throttle, and the prop set at 2,300 rpm. (Pardin the dust. Look at the true, and then look at the yellow. "How many of those naut thingys are there still in this airframe before tickling that thar yeller part that'n wer s'posed to be afearin." This is why I felt like I got laid away by being convinced to put a dinky little sissy engine in my plane. When I was deciding there was no picture like this!
Scott, I'm on your side in this stuff, but for the engines we are talking about, normally aspirated O-320s and O-360s I can't find anything from Lycoming that limits the engines to 75% continuous power. I believe they are rated at 100% continuous power. Please advise me if I am wrong. I certainly can't find anything about a 75% power limitation....We all know that Lycoming has set that at 75% for most of their engines...
I have no intention of arguing with you Brian...but you just don't seem to understand the difference between IAS and true airspeed.
Lets assume your power setting was 75% power when you took your photo.
Now go fly your airplane at 2000 ft AT 75% power and take a photo of it.
I bet you the IAS will be well into the yellow arc.
BTW, I am aware of what I wrote in my other post. I never mentioned any specific altitude. An RV doesn't have to be above 8000 ft to be considered to be in cruise flight.
You seem to be stuck on higher altitudes. the design issue is that at 75% power at any altitude the IAS should be in the green arc.
A 180 HP RV-9 cruising 75% power at 2000 ft will have an IAS that is in teh yellow arc range.
We're going to have to agree to disagree. I don't want to argue with you either, but you should know just how condesending your response to the picture was. It certainly had the potential to encite rage.
While my plane meets the published specs or better , it lacks the ability to get to the yellow unless in a 200 fpm decent of so in cruise. As for going all in down low, well that is what a throttle is for.
Scott, I'm on your side in this stuff, but for the engines we are talking about, normally aspirated O-320s and O-360s I can't find anything from Lycoming that limits the engines to 75% continuous power. I believe they are rated at 100% continuous power. Please advise me if I am wrong. I certainly can't find anything about a 75% power limitation.
Brian,
I want to apologize if that is the effect my post had. I am not always good with words. That is not the intent I had, I am sorry. I also hadn't noticed previously that you represent your airplane as having 170 HP, not 180. You have always seemed to be a big proponent for using 180 HP in an RV-9 so I made an incorrect assumption.
The point I was trying to make was that showing an IAS at 8500 feet that is in the green arc is not relevant to the reason the RV-9 is recommended for engines only up to 160 HP. A 180 HP RV-9 at 75% power at 8500 ft probably would be about 7-8 mph IAS short of the yellow arc, but at 75% power at 2500 ft it would have an IAS that was well into the yellow arc. Please note that at 2500 feet, "all in" is not 75% power, it is well over that.
That is the reason the RV-9 is only approved for up to a 160 HP engine.
I think you are correct that they are rated at 100% continuous, however this is from Lycoming for normally aspirated engines:Scott, I'm on your side in this stuff, but for the engines we are talking about, normally aspirated O-320s and O-360s I can't find anything from Lycoming that limits the engines to 75% continuous power. I believe they are rated at 100% continuous power. Please advise me if I am wrong. I certainly can't find anything about a 75% power limitation.
In the case of an RV-9 with 180 HP flying at 2000MSL at 75% power, the IAS would be well into the yellow.
Not to beat a dead horse here but this is not true for my beast. I guess I had better get those wheel fairings finished....