A1V8A2 Posted September 28, 2008 Share Posted September 28, 2008 Hello all, first post here. I'm new to the homebuilding thing so bare with me. Piston engines are obviously really easy to acquire, but how do you get your hands on jet engine? I have not seen any way to purchase online. I know EZ Jet does conversions, but I'm looking for a little more power, like a J85 maybe. Anyway, any help or insight would be appreciated. Quote Link to comment Share on other sites More sharing options...
WileEZ Posted October 11, 2008 Share Posted October 11, 2008 Contact your local FBO that also works on turboprops and light jets. They should be able to at least point you in the right direction if not actually order the engine for you. Quote WileEZ "All of my ideas are suspect until proven otherwise!" Link to comment Share on other sites More sharing options...
Big Steve Posted October 11, 2008 Share Posted October 11, 2008 You can get anything you want if you have lots of money and let the right people know. It is the cheap stuff that is hard to find. I see jet motors for sale all the time on different sites. Barnstormers, ebay, local aviation sites. Advertise and let people know you are looking and that you have cash they will find. you. STeve build on Quote Steve Harmon Lovin Life in Idaho Cozy IV Plans #1466 N232CZ http://websites.expercraft.com/bigsteve/ Working on Chapter 19,21 Link to comment Share on other sites More sharing options...
Arbiter Posted October 12, 2008 Share Posted October 12, 2008 Hello all, first post here. I'm new to the homebuilding thing so bare with me. Piston engines are obviously really easy to acquire, but how do you get your hands on jet engine? I have not seen any way to purchase online. I know EZ Jet does conversions, but I'm looking for a little more power, like a J85 maybe. Anyway, any help or insight would be appreciated. Hi A1V8A2, welcome to the forum! Getting ahold of a jet engine is probably not easy, but certainly not impossible. I do not know your background with turbine engines, so let me put forth a few things one might consider when thinking of purchasing a turbine engine: 1. Consider the mission. I do not know if you want to build a Cozy or Long EZ with a jet engine in the back, but be mindful of why jet engines came about. Jet engines were designed to go high and fast, but burning a lot of fuel. By fast I mean 300+ MPH, which means that for the canard aircraft this forum discusses (Not counting the business and war aircraft) these speeds are not in their design envelope (What are the top speeds people have seen in safe level flight?). Modifying one of these for a jet engine has been done before, but I doubt the person's aircraft served the mission it was designed for (Range, cruising efficiency, etc..). If you don't care about that then read on , Jets are cool, and I wouldn't mind seeing more! 2. Consider the fuel burn. The J-85 you speak of burns 400 Gal/hr at TKO. Now lets say just for fun you somehow burn even 1/8 of that (I am really trying here), in a stock Cozy you'll have 52 gallons of fuel... That's not enough to fly for an hour with reserves. So you'd need to make the airframe heavier and draggier to get more fuel in (After you make the whole back seat fuel you'll want to put some pods in too or something. That leaves you with less weight to carry as passengers/baggage (This takes it back to how the original mission changes). 3. Consider the CG changes and how that will affect the airframe weight The J85 is longer than the Lycosaurus, and will thus put it's comparable weight of ~400-500 lbs installed farther aft. This will have an adverse affect on your CG limits and will require more weight be put up front to keep the airframe stable. This could be accomplished by lengthening the fuselage to get the passenger weights back up front (And add room for more fuel, so.... BONUS!) to help compensate more. If you go down this path I recommend talking to Chris Esselstyn who stretched his a foot or so. 4. Consider the maintenance required. I am not sure how the turbine world manages their maintenance for home-built turbine installations, but the rotating parts in these turbines are life limited to engine cycles, not hours. You need a way to know what the life is on each critical rotating part and have the maintenance capabilities to overhaul the engine once the number of cycles on a critical part expires (Cycles aren't necessarily the same as 1 flight either, especially if a lot of throttle excursions are incurred during a given flight). I've taken apart a CF34 down to a compressor top-case and it was a 3 day affair with 5 guys on it. Flanges weren't torqued or recently coming off a running engine (This was at training school) so i would imagine this time would go up significantly. Not to mention the parts cost, and you really don't want to risk leaving life limited hardware in there past its time, I know I would not fly in it unless I knew all the parts were significantly below the life limits and all the FAA recommended/mandated upgrades were put in. Bottom line = $$$$$$$$$$ Mucho Bucks. If all of this has you still wanting to put a roaring J85 into a canard aircraft, by all means I encourage you to go ahead and do it, I just want you fully informed (Or as much as I can help, others may chime in too if I left a lot of gaps) about how much different and how much more expensive a turbine installation is going to be if it's done right. As far as where to purchase one, I would check barnstormers, but again I'd be really careful that you understood and had DETAILED maintenance logs you trust on the engine you purchase. This was a failure I found on google images. You can see where the fan failed. There was a kevlar containment case there.... These people got really lucky. Good luck and if you do decide to put a jet engine in, let us know and keep us posted on the progress! -Chris Quote Chris Zupp ~Aircraft Designer~ Preliminary Design Sequence I: Project Endeavour Aeronautical/Mechanical Engineer Private Pilot Link to comment Share on other sites More sharing options...
Marc Zeitlin Posted October 12, 2008 Share Posted October 12, 2008 If all of this has you still wanting to put a roaring J85 into a canard aircraft, by all means I encourage you to go ahead and do it...That's just silly. A J85 only has between 2600 - 3800 lb. of thrust - that'll barely accelerate a MGW Cozy MKIV at 1.3 - 1.9 G's, or 0.3 to 0.9 G's straight up. That's pretty paltry performance, IMNSHO. Plus, the 600 lb. weight of the raw engine would throw off the CG, and once you got to 50K ft., you'd be out of gas. Seems like a poor choice of engines to me. Far more reasonable for a COZY MKIV engine is something along the lines of an "Orgone" engine, like: http://www.linux-host.org/energy/borgone.htm See? No fuel needed at all - as much power as you want - solves all the issues here. With an infinite amount of power, you can accelerate to the 220 mph Vne in less than a second, be at orbital altitudes in no time, and not bother with having to deal with any of those pesky laws of physics, aerodynamics, or rationality. My signature file at work has: "Non Impediti Ratione Cogitationis" as the last line - I should put it on my signature file here, too :-). Quote Marc J. Zeitlin Burnside Aerospace marc_zeitlin@alum.mit.edu www.cozybuilders.org copyright © 2024 Link to comment Share on other sites More sharing options...
A1V8A2 Posted October 13, 2008 Author Share Posted October 13, 2008 Wow, thanks a lot. Obviously the J85 is totally impractical for use in a Cozy or related craft. I just really think it would be great to see a relatively affordable, high speed, and aerobatic carnard homebuilt. My actual turbine experience is zero, I've just been a fan of the ViperJet for a long while. Ultimately, I'd like to work on a canard design with similar proportions and performance as the ViperJet. I'm just doing some homework now. Thanks for the help. Quote Link to comment Share on other sites More sharing options...
bferrell Posted October 13, 2008 Share Posted October 13, 2008 You might want to talk to X-Jets, they helped Antonio with his installation http://wiki.velocityxl.com/index.php?title=Espinal_Jet_N289AE Brett Quote --- Brett Ferrell Velocity XL/FG Cincinnati, OH http://www.velocityxl.com Link to comment Share on other sites More sharing options...
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