RV-9 AND 0360

[henriquerv9]

HI GUYS,

JUST WONDERING HOW MANY 9'S ARE FLYING WITH 180HP AND WHAT PROPELLER CHOICE THEY ARE USING...

I AM READY TO INSTALL A BRAND NEW ENGINE IN MY 9A BUT STILL IN DOUBT OF WHAT PROP USE... SHOUD I USE THE RV7A SENSENICH OPTION (72FM8S9-1-85) ? OR THERE ARE ANY BETTER SUGESTIONS?


REGARDS

HENRIQUE

 

[gorbak]

180HP in a 9(A)

You may wish to consult Van's with this idea of a 180 HP engine in a 9A. Van's has an informational link on this subject at
http://vansaircraft.com/pdf/hp_limts.pdf

Hope this is helpful. Have a great day

Gorbak
9A 942PT (reserved) Wiring
9A 942WG (reserved) Finish work and paint

 

[ww2planes]

I have a friend with a 180 HP 360 and a Hartzell C/S. That thing goes up like an elevator. The rate of climb is amazing and even more amazing to watch from the side of the runway. He recently reworked the engine ans hoping for over 200 hp. Crusie with the old engine was only about 185 mph not corrected.

 

[mdredmond]

The reason Van's doesn't recommend a -360 for the RV-9 can be found in these cool but scary videos:

http://www.airandspacemagazine.com/ASM/Web/Site/QT/A6Flutter.html

http://www.airandspacemagazine.com/ASM/Web/Site/QT/TCFlutter.html

The bottom line, quoting from Van's article is: "Why not put a 180hp engine on an RV-9? Because it will go too fast!"

...although I guess with a good TAS instrument you could take advantage of the climb performance and relatively low load on the engine in cruise while avoiding the danger of overspeed.

 

[henriquerv9]

speed restricions

I know the risks about speed limits using the 360. But, besides and if you are cautious about that, is there any other restrictions that we need to be aware of?

Also I would like to hear from whom is already flying this configuration, the pros and cons of using a 360 and how is the level of satisfaction...

 

[smithhb]

I would like to hear from whom is already flying this configuration, the pros and cons of using a 360 and how is the level of satisfaction...

Have you looked at the ECI IO-340 Stroker engine? It is built on a 320 core and with 9:1 pistons turns 185hp!

 

[godspeed]

new engine

If I was going to do it over (I already have my engine installed) I would by the 340, weight is an
issue, some others have detuned the 0360 to 170hp
and they have said if they did it again they would
leave the other pistons in instead..


Danny.. headed to airport

 

[Bryan Wood]

0-360 in a 9

How about we start to collect some data and crunch it here ourselves? This weekend I'll take an up close picture of my airspeed indicator and altimeter with everything pushed forward at an 8K density altitude. You will all see that there is no way that I'm close to the yellow, and with the trues calculated I'll bet it is so far under the 210 flutter restriction were all talking about lately it will surprise all of you building at this time. If it were me, I'd probably go 0-360 without derating it. How about others with flying nines, how about pictures of your airspeed indicators and altimeters with temperature information outside while cruising. If anybody is seeing over 140-145 knots indicated I'll be surprised. The yellow starts at 180mph or what 156 knots. We are being very safe indeed running 0-320's.

Regards,

 

[n2prise]

220 MPH true air speed on descents...

I remember one day during my phase one testing when I was hurrying back home before dark and the descent was a bit faster than I planned. I was watching the INDICATED airspeed during the descent and moving right along from 10,000 heading down when I realized the TRUE airspeed was touching on 220 MPH at 2300 RPM on my 160 HP O-320 with constant speed Hartzell prop. I talk about some of that experience on this page: http://www.n2prise.org/rv9a140.htm Be sure and look at the US FLAG picture showing the wear on it due to high speed fllight.

Needless to say, I have not been there again. No flutter that time, but I would have to say I was pushing the envelope without knowing it at the time.

As for the cruising, I spend a lot of time between 10,000 and 13,500 MSL at full power, 2300 RPM, posting 160 MPH TAS leaned to SIX gallons-per-hour with all the EGT's just about even from my carburetor and induction system.

One other thing to note: At 1000 MSL straight and level, 2300 RPM, full throttle produced 193 MPH both times I tried it. The fuel burn rate goes WAY up there, and needless to say, the manifold pressure is way over "square" at 28 inches or more. I spend most of my time cruising at 160 MPH TAS no matter what altitude I fly. Sometimes I pull the power back to 140 MPH at 2300 RPM when I want to fly "slow" and really save gas. I fly the pattern at 100 MPH downwind with no flaps and 80 MPH on the final approach with full flaps.

Jerry K. Thorne
RV-9A N2PZ "Enterprise"
189.6 Hobbs Hours since June 2005
www.n2prise.org

 

[RVbySDI]

...although I guess with a good TAS instrument you could take advantage of the climb performance and relatively low load on the engine in cruise while avoiding the danger of overspeed.

That leads to a question I would have concerning using a G-Meter in an RV9A. In addition to the TAS instrument it seems to me that it would be beneficial to also have a G-Meter instrument that would measure the load factor the airframe is flying under. Would using a TAS instrument and a G-Meter together help to reduce the risk of reaching a structural limit of the aircraft? If the 9(A) is rated for +3.8/-1.8 G's and Vne is 210 mph (??) and you had the TAS and G-Meter, could a pilot maintain a safer flight envelope at altitude and at a fast cruise speed than if he did not have those instruments? Or would knowing those things be of little consequence in that situation?

I am not questioning in any way the issue of limiting speed but I guess what I am getting at is, would it be considered safer to equip your airplane (no matter what the engine size) with a TAS instrument and a G-Meter and then to use them carefully when cruising at high altitudes and high airspeeds or when making steep turns or rapid descents (abrupt maneuvers)? I can see where an occasion could arise where a pilot would push the nose over at altitude and very quickly reach the upper limits of the rated airspeed for the airframe. If doing so with these instruments on the panel, could you head off a potentially disasterous situation before you ever got started in the risky maneuver?

Anyone with experience in an RV9 using a G-Meter and/or TAS? I would welcome any comments on these questions as I am approaching the point where I should start considering what instruments to put on my panel.

 

[Kahuna]

I could have written this thread, and the rest of the messages still to follow, based on the first message.
You guys crack me up!
Matt, come on. A flutter video of an A6 model in a test tunnel at .86 mach?
Cant wait to hear the rest of the diatribe coming.

 

[Robert M]

With all the talk about the overspeed possiblity with a 180+ hp engine, is there anything on record where there has been a structural failure because of overspeed?

Me personally, I'm going with the recommended engine size (O-320) because I'm not comfortable pushing any limits. Why risk a chance of "not paying close attention to TAS" and rip a plane to pieces? Don't these things fly fast enough? I'm not trying to cause a fuss but if speed and power are the basis to purchase a plane - buy one that will go the speed you want. I'm sure there are faster and better climbing kit planes than the RV's - aren't there? Doesn't the RV-7 with IO-360 & CS climb beter than the -9?

 

[joe gremlin]

Would using a TAS instrument and a G-Meter together help to reduce the risk of reaching a structural limit of the aircraft? If the 9(A) is rated for +3.8/-1.8 G's and Vne is 210 mph (??) and you had the TAS and G-Meter, could a pilot maintain a safer flight envelope at altitude and at a fast cruise speed than if he did not have those instruments?

I believe the short answer to this is no. The reason being, the primary limiting factor is the g-load the wings will take which is tied to gross weight and how strong the wings are. As has already been stated you may safely exceed Va and sometimes even Vne so long the air is smooth. The problem with that is that bumpy air doesn't always come with a warning so what happens when the air is smooth and you've got the throttle to the firewall when suddenly you encounter some clear air turbulance? Va is designed so that the wing will stall before max-g is reached thereby unloading the wing before damage or failure. But if you're screaming along at close to or above Vne TAS and encounter sudden unexpected turbulance, you could quickly exceed the +3.8 max wing load without stalling the wing. In this case the G-meter wouldn't help you at all because it would all happen before you had time to react.

The G-meter would work in perfect world where the unexpected never occured. Unfortunately we don't live in perfect world.

 

[rv8ch]

Stroker

Have you looked at the ECI IO-340 Stroker engine? It is built on a 320 core and with 9:1 pistons turns 185hp!

That does look like an excellent engine for the 9, and would also probably be great in a 7 or an 8.

 

[mdredmond]

Matt, come on. A flutter video of an A6 model in a test tunnel at .86 mach? Cant wait to hear the rest of the diatribe coming.

My point was simply to show a pretty cool are rare video of flutter in flight (not the wind tunnel).

Flutter is flutter - at 220 or 550 mph - it will rip your tail off. You'll be a lawn dart in a couple of seconds or a quarter second. Call me stupid, but I fail to see the difference.

Van and his guys know far more than I do - I'll be following their recommendations. The NTSB database is full enough as it is.

 

[RVbySDI]

I believe the short answer to this is no. The reason being, the primary limiting factor is the g-load the wings will take which is tied to gross weight and how strong the wings are. . . In this case the G-meter wouldn't help you at all because it would all happen before you had time to react.

The G-meter would work in perfect world where the unexpected never occured. Unfortunately we don't live in perfect world.

Thanks for the info Joe. My thinking was that these two instruments might be beneficial at cruise to help me keep an eye on the load factor for the airplane. Since cruise speed seems to be close enough to the Vne that you could accidently exceed that speed very quickly, these instruments might serve as an additional warning if something like gusts or turbulance push your airframe to the maximum limits unexpectedly. If they were present and you could set parameters so that a warning would sound if you exceeded the setting you could quickly decrease power or change attitude to decrease the speed or loading. It was just a thought.

 

[Yukon]

Flutter

I could have written this thread, and the rest of the messages still to follow, based on the first message.
You guys crack me up!
Matt, come on. A flutter video of an A6 model in a test tunnel at .86 mach?
Cant wait to hear the rest of the diatribe coming.

Kahuna,

Did you even download the videos??? What is not pertinent about real-time,
inflight video of a Twin Commanche stabilizer fluttering in flight? Should be required viewing for the "hair on fire" types.

http://www.airandspacemagazine.com/ASM/Web/Site/QT/TCFlutter.html