Aaron

I saw one powered by a motorcycle engine, 60mph capable, for under 10 grand (as a kit) Since it's an ultralight copter, you wouln't need a license, nor would you need to file a flight plan.

I think I'll start from scratch though, whichever one I go with.

is this the induced drag: 1/1/2pV2(W/b)2 What's the definition of W and b?

The parasitic drag is: [Parasitic Drag]=[Coeff of P.D.]*[surface area]*1/2*[air Density]*[Velocity]^2 The problem is that Coefficient of parasitic drag, right? Well, we know that the flat plate equiv for a Cozy is around 2 square feet, and that Flat Plate Area= [Coeff. of P.D.]* [surface area] Did I miss anything? I'm not used to these aerodynamic formulae, but I think that's it. Still thinking about "alternate propulsion", MT? http://142.26.194.131/aerodynamics1/Drag/Page1.html

Can we expect to see many of the Rutan clan there? I'd hate to get out there just to see a bunch of backward looking RV's with those silly looking piston engines...

http://www.scudc.scu.edu/spec/mcad/analysis/MIL-HDBK-17-2E.pdf 451 pages of composite materials tests.

I like the KISS method for fuel, I see WAY too many accident reports caused by bad fuel systems. Are you using a pressurized system? As for blasphemy, I'm not the religous type. Most auto manufacturers figured out pumps go in the tanks- I'm still not sure why some people put them on the engines. Alas, EFI is in my future, with all the PITA plumbing that goes with it. Slade found a nice place under the rear seats for pumps, Which should keep a few feet NPSH on the pumps, but this is going to be a system I tread very carefully with. Good thing I design piping systems in my day job Thanks again for turning up the gain.

BHP- Brake Horsepower, is the power required to keep an engine from accelerating past a given RPM. The torque is measured and converted to BHP (BHP=torque*rpm/ 5252) and it's the constant RPM power of an engine. While your comments certainly apply to automotive applications, an airplane is a constant speed application of an engine, so I'm missing your point. Are you saying the BHP measured for a Lycoming is different from the BHP measured for a Mazda? How? Me I love reinventing the wheel, that's why I'm so interested in building- I want my plane to be truly mine, and that includes selecting the right engine for me. At the same time, I can certainly understand the desire to plug in a proven engine and GO. Now on to a completely different topic. I've heard plenty of reviews on 1 and 2 year old planes, but never a 12 year old EZ. What's the long term upkeep like? If you were to do anything differently, what would it be?

No you were well equipped. My 100 lb niece could have loosened it with an 8 foot pipe

I think you're getting confused with the numbers here. if you car's engine was truly generating 320 Hp and the wheels were putting down only 54 Hp then something was absorbing 266 HP, but that's not likely to be the gearset. Maybe your clutch was slipping, or maybe there was some other problem and one or both of those numbers is wrong. Think about it, how could the gearbox absorb 266 HP? Thats 200 kilowatts of heat. Thats like having 200 1000 watt bulbs dissapating heat energy under your car-that's a LOT of heat to be generated by a gearbox. The highest driveline losses seen today in the automotive world are on AWD cars like the Audi Quattro system, and those are about 25% (due to 3 differentials) FWD economy cars get around 10-15% driveline loss, and a PSRU loses even less because it's only a planetary gearset, no differential. If you look at piston engines they are 30% efficient at converting the chemical energy of gasoline into motive force, maybe that's where you came up with that number? As for "alot less moving parts"- you're wrong again. If you have a 4 cylinder engine you have: 4 pistons moving, 4 wrist pins, 1 crankshaft, 1 camshaft, timing chain, at least 8 lifters, 8 pushrods, 8 rocker arms, 8 valve springs, 8 valves in the engine: 55 parts moving. Much of it at very high service temperature, which thins out oil films. In a rotary: 1 eccentric shaft, 2 rotors: 3 parts moving Add a 4 or 6 planetary gear set and how many parts do you have? less than 15 total? Based on your own logic, less parts moving equals less things to go wrong, right?

Too bad he moved on before demonstrating the capabilities I'm not trying to convince you, I'm just trying to figure out where all these misconceptions come from. If you tell me you've never seen a fast auto conversion that's fine, but have you ever seen a rotary conversion compared to the same plane with a piston engine?

Where are people getting this info that engines are designed based on their "Average" power output? Several times now I've been told that since auto engines are designed for only 30 hp, they wont work in airplanes. ???Where does this logic come from??? Let me make an engineering analogy-A footbridge. Now this footbridge is only used a little a day. It's average load might only be a few pounds. Yet if we designed it for a few pounds it would fail the first time we stepped on it. When designing a structure, you design it for the maximmum load, not the average load. Inside the engine case-you design for 110-130% of rated power output. That's how all the bearings are sized, as well the oiling holes and cooling jacket sizes. Outside the engine it's a different matter- You build capacity into the cooling systems at other than 100% power. but inside the engine case you have to design everything so that it can take full power stresses. Don't get me wrong, There's nothing wrong in using an aircooled flat piston engine in aircraft, it's just not what I choose to do. I wouldn't drive an aircooled car around (not even a Porsche) so why drive an aircooled plane around. just my 2 cents.

We're talking about running the engines at 75-80% not redline. These engines are nothing like auto piston engines so drawing parallels there is about as effective as comparing your engine to a rotary. If you wish I can cite several examples of Mazda engines flying trouble free for 100's (and 1000's) of hours in experimental aircraft. Hmmn, 30% is a bit on the high side, even auto transmissions have drive line losses of 10-15%, and that's after going through several gears and the differential. Can you state a reference for your "fact"? Well since I'm the only "Number Cruncher" here, I guess this post is directed at me:) but I really don't know why your "testy" with me. Perhaps you think I should be farther along on the plane. Considering I haven't selected a plane yet to build, I've got quite a ways to go. Yet even at my limited experience I realize that some people build to fly, some build to learn. I could be farther along if I "build and shut up", but then I'd be just as ignorant as when I started. Me, I'm in it for the learning, so I'll take my time, if thats OK with you. I look forward to learning more from you when you get back from you hamburger run.

the stand bolts to studs on the front cover (Iron piece)

Another view from the engine's perspective

If you've ever tried to mount a rotary to a typical engine stand, you've discovered it don't work well. You need to attach the engine stand to the Front cover to make assembly/dissasembly a snap. These sell for like 60-90 bucks which bugs me. It's a frickin piece of steel, this sort of thing can be made by hand by any shop in 5 minutes and the material would cost $15.00 at most So I built my own. I used a 3' long piece of angle iron, cut into 4 pieces. The pieces are nested together to form an upside-down lowercase letter "h" If you have access to a welder, you can weld this up, or if you're like me you can use two bolts to hold it all together. This adapter has some spring in it- it moves a bit when I stand on it with the engine attached, but it seems pretty safe so far.

Chris, The search for knowledge is never over We were musing this weekend over what objections people have over the Velocity, I'm just trying to open things up into a nice healthy debate. I hope there are some completed Velocity's or Cozys at SWRFI- that's when I make my decision. Exciting times

John- as for the Renesis it's 250HP at 8500RPM. Assuming that 2.8 redrive is to turn a prop at 2400 rpm, you're looking at 6700 rpm on the engine. Considering this engine's dyno plot you're talking about 200 HP (approx). Still a great engine for this application, don't get me wrong- I'm just the numbers guy. Dust-Sorry I thought Al was driving an IVO prop, my bad. I originally was looking at IVO's adjustable stuff-Adjustable makes sense to me, but the price of most constant speed props doesn't. And then seeing about that family who died due (presumably) to improper bolt torque...Well lets just say it's one story I'm not sharing with my wife, but I'll keep in the back of my head next to my skydiving skills. As for props- I've go PLENTY of time before I worry about this, plenty of time to wait and see how Lamar's experiment goes.

http://cozyaircraft.com/forum/showthread.php?s=&threadid=248 I've thought about it myself, just be sure you know what the maintenance routines are, it would suck to die from your experimental aircraft, even worse when you think about wiping out your whole family...or someone elses.

I think you mean you need to shield the exhaust half of the turbo and the manifold from everything else. I've seen this done using insulated pads which tie on around the exhaust piping, they're made to withstand 2000F heat. I did see one lancair where the builder used a carbon composite material outside the silica fabric, but I'm not sure it ever flew: http://www.hannestrnka.com/heat_shield.htm It shore is purdy though :0 look at his CF ducts: http://www.hannestrnka.com/cooling_air_ducts.htm

Hey dust, what do you need the High-temp stuff for?

ACP (Aerospace Composite Products) e-mail: info@acp-composites.com has a resin they call EZ-LAM HT: E-Z LAM HT High Temperature Epoxy Laminating Resin DESCRIPTION: An ultra high temperature laminating system for the construction of laminated composite parts. E-Z LAM HT has excellent wet-out characteristics, facilitating lay-ups involving compound contours. Its long pot life allows for ease of vacuum bagging . The maximum operating temperature for laminated parts manufactured from E-Z LAM HT is 450 Deg. F. MIX RATIO: 100 parts by weight E-Z LAM HT A 33 parts by weight E-Z LAM HT B POT LIFE: 150 gr. mass 4 HRS. @ 75 F CURE: ROOM TEMP SET FOLLOWED BY 2 HRS. @ 150 F 2 HRS. @ 200 F 2 HRS. @ 250 F 2 HRS. @ 300 F 2 HRS. @ 350 F ALLOW TO COOL IN OVEN PROPERTIES: VISCOSITY, MIXED 5000 CPS DUROMETER D 94 SHORE SPECIFIC GRAVITY 1.19 gm/cc USE TEMP, 400 F FLEXURAL 102,000 PSI COMPRESSION 64,000 PSI TENSILE 57,000 PSI SHELF LIFE: Twelve months when stored in tightly sealed containers at room temperature. SAFETY: Avoid contact of resin or hardener with skin or eyes. Wear disposable gloves and eye protection. Avoid breathing vapors, apply under good ventilation. If contact occurs consult physician. For more details refer to E-Z LAM Safety Sheet.

I'm still in the air I like the Cozy, but I visited a local Velocity project yesterday. I was impressed by the accessability the gull-wing doors gave. I'm not making the decision until I sit in them both, but could any of you who have been in this spot before tell me how you came to your decision. Note: I've been here long enough to know this subject brings up some sore feelings so if you would like to send your messages in private, please feel free to do so.

Up there, how much to month-month hangars run? Or is that a "If you have to ask then it's too much" kinda thing.

What if someone finishes before you- do you get bumped?