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~\ io-540 /~


TES111

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I beg to differ about the cargo space. The Cozy can carry ALOT of stuff, especially if you're traveling just two. Check out the "cargo" picture from my Sun N Fun trip report.

http://www.maddyhome.com/canardpages/pages/waynehicks/index.html

 

As for the IO-540, there is at least one builder putting a 540 on the back of a Cozy. There are several that are hanging 'em on AeroCanards. It's doable as long as one works out the weight and balance.

 

....Wayne

Wayne Hicks

Cozy IV Plans #678

http://www.ez.org/pages/waynehicks

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Good question Jake. Any takers for the vne? I was hoping to not eliminate interior space. However if it is to large for a typical install it has to go somewhere. Right? I know that Velocity makes a 540 engine mount. I have also seen the aero cad builder sites that show their 540's installed. Just wanted to know how you would go about doing such a thing. You know, pick a brain or two. I am not a builder but am going to purchase plans very soon. I would like to have more answers than questions prior to starting the build. Notice I said "prior to". I would like an RG cozy with a 540. I know the rg is possible. Now for the 540.

 

Regards

 

The newbie

TES111

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Originally posted by JakeC

Speaking of that, what is the VNE for the Cozy? Thanks in advance.

Jake

These numbers are available on the www.cozyaircraft.com web site, as well as the www.cozybuilders.org web site. Vne for the COZY MKIV is 220 mph IAS.

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Thanks for the info Mark. Cozyaircraft.com was the first place I looked for the VNE but they have left it off the spec sheet for some reason. Do you know of anyone that is modifying their cozy in order to raise the VNE? It seems that with some of the higher HP installations going on that it would be pretty easy to exceed that number with the Cozy. Is this even an issue at cruising altitudes? The way I understand it the higher you go the lower your indicated airspeed. You have to forgive my ignorance in this matter. I'm not yet a pilot and I may have a skewed view of what is possible with indicated vs. true airspeed at higher cruising altitude.

 

Jake

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I don't have the exact numbers at hand, but if you can indicate 200 at 15000 then your true airspeed will be over 250, (depending on temperature, barometric preasure and humidity) now don't confuse this with ground speed. But do confuse it with calibrated airspeed. Calibrated airspeed corrects yor indicated airspeed by it's mechanical/installation inacuracies.

 

Indicated is how the air is acting on the plane, true is how fast you are moving through the air and ground speed is how fast you happen to be going over the ground.

maker wood dust and shavings - foam and fiberglass dust and one day a cozy will pop out, enjoying the build

 

i can be reached at

 

http://www.canardcommunity.com/

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Indicated Airspeed (IAS) is the measure of dynamic pressure. Static pressure is what is all around us, and decreases with altitude (altimeter). Dynamic pressure is the pressure achieved from motion through the air. Aircraft have a pitot tube/head, in which it measures static pressure( a hole facing downwards) and dynamic + static pressure ( a hole facing forwards). With the use of a bellows, with dynamic + static on one side and static on the other, the little gauge shows Indicated Airspeed, or dynamic pressure. Stall speeds, and best rate of climb etc are all IAS. IAS indicates how much lift you are getting.

The pitot tube may not always be in an ideal place, so position error is accounted for and you get Calibrated Air Speed (CAS). Then at speeds exceeding 200 mph, air becomes compressable, and you need to compensate, giving you Equivalent Air Speed ( EAS).

Then of course you have True Airspeed (TAS) which is EAS compensated for density (pressure + temperature).

Ground Speed is TAS compensated for wind movement.

So what does that mean? well if you climb at a constant Indicated airspeed, as you gain height the density decreases, therefore your True airspeed will increase.

An U-2 spy plane at 82,000 feet has an indicated airspeed of 150 KIAS, but it is travelling through the air at 400 KTAS, and if it gets in the jet stream, it could have a ground speed of 600 Knots.

Vne is measured in IAS, and above 220 mph indicated I would imagine to be quite dangerous. Yet as you increase altitude density decreases, so a TAS of well above 220 mph will be possible. The next limiting factor will be Mach number, because the speed of sound is dependent on temperature not density. An Air Racer at Reno achieves about Mach 0.68 average speed on a lap.

Try this TAS calculator http://www.csgnetwork.com/tasinfocalc.html

 

:D :D

The Coconut King

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Originally posted by JakeC

Thanks for the info Mark. Cozyaircraft.com was the first place I looked for the VNE but they have left it off the spec sheet for some reason.

I apologize - neither web site specifically calls out Vne. It has been discussed numerous times, but you'd have to search the COZY mailing list archives to know that.

 

Do you know of anyone that is modifying their cozy in order to raise the VNE? It seems that with some of the higher HP installations going on that it would be pretty easy to exceed that number with the Cozy. Is this even an issue at cruising altitudes?

I know of one person that was going to use an O-540 that had done extensive mods on structure and airfoils, but he is no longer pursuing his project and it never flew. Other than that, no. Since we've never gotten a good answer from Nat regarding the limiting factor in Vne (structure, flutter, etc.), it's hard to know what to modify without doing a full analysis, which very few of us are capable of doing.

 

The way I understand it the higher you go the lower your indicated airspeed. You have to forgive my ignorance in this matter. I'm not yet a pilot and I may have a skewed view of what is possible with indicated vs. true airspeed at higher cruising altitude.

To a rough approximation, TAS is higher than IAS by about 2% per 1000 ft of altitude. So, at 10k ft, add 20% to your IAS to get TAS. The issue for Vne is IAS. I can indicate ~160 mph at 10,000 ft (no wheelpants yet) on about 65% power (117 HP). With Vne at 220 mph, I'd need 2.6 times (220/160)^3 as much power (304 HP) to get there. You won't get that out of an O-540.

 

At low altitudes, where IAS~=TAS, yes, there will be a problem - you'd easily be able to exceed Vne.

 

Does this help?

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Mark: Yes, that was a big help. When the subject of the 540 came up it sort of got me thinking about the Mazda 20b which I believe is similar in weight. I believe with the numbers you mentioned the 20b could come close to pushing the VNE at altitude. The extra weight and bulk would be tough to deal with as well. And really with the new Mazda Renesis coming out there will be no need to look at the 20b for increased power. The Renesis is actually smaller and lighter than the 13b and develops 250hp in a stock normally aspirated configuration.

 

No4: Thanks for the detail. I appreciate it.

 

TESS111: I'll shut up and let you have your thread back. No more Mazda talk!! :D

 

Jake

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the cost of the engine i am buying is 7500 with starter, alternator,fuel injectors/pumps, mags, vacuum pump, prop govenor and the turboe.

 

It is a 210 hp rated engine

 

The tbo on this model is 1400, it has 2000 (600 smoh). when new pistons, chrome cylenders, etc. etc. were installed.

 

How fast will it go, ????? who knows, Not I. But in my analysis, why go to a 540 that has to be leaned out at altitude, when a turboe will effectivly do the same with less weight and fuel burn.

 

The problem I am facing is a completly independant install, from the engine mount that needs to be fabbed to higher weight and heat retention, exhaust pipes to make, etc,etc

 

DONT CHANGE THE PLANS WITHOUT UNDERTSTANDING THE TREMENDOUS AMOUNT OF WORK IT WILL TAKE!

maker wood dust and shavings - foam and fiberglass dust and one day a cozy will pop out, enjoying the build

 

i can be reached at

 

http://www.canardcommunity.com/

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What sort of CS prop are you going to use dust?

I spoke to some Cessna people, and was quoted $7500 for an overhauled pusher CSU, I think with electric de-ice. I'm pretty sure it was designed for the TSIO 360.

That's a lot of beer tokens, but the advantages of a constant speeder are very seductive.

The Coconut King

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