http://www.lucubration.com/cozy13bt/ 2012-05-19T12:38:29-04:00 http://www.lucubration.com/cozy13bt/ http://www.lucubration.com/cozy13bt/lib/images/favicon.ico text/html 2010-08-18T09:18:12-04:00 http://www.lucubration.com/cozy13bt/airframe?rev=1282137492&do=diff The following modifications are required to install a 13BT in your Cozy. These particular steps are very open to criticism. You can easily go a different way with each one - but for each step, you have to do something to address the issue that I was addressing. text/html 2010-08-11T22:26:44-04:00 http://www.lucubration.com/cozy13bt/cleaning?rev=1281580004&do=diff How clean is clean? Some parts of the engine, such as the apex and side seal grooves, need to be as clean and free of carbon buildup as possible to get the best performance out of the engine. Other areas, such as the outsides of the housings, only need to be as clean as you want them to be. Still, it's hard to inspect the engine parts properly without cleaning them, so unless you see obvious signs of damage you should do this step first. text/html 2010-09-01T09:44:15-04:00 http://www.lucubration.com/cozy13bt/compression?rev=1283348655&do=diff A rotary engine seems elegant until you try to perform a compression test on it. Each rotor has three faces, and each face has its own apex and side seals. You need to check all three for each rotor. You also need to check them at cranking speed, not by turning the engine over by hand. Compression varies with rpm, and Mazda specifies that the check be performed at 250rpm, the normal cranking speed of the engine. text/html 2010-07-27T22:24:23-04:00 http://www.lucubration.com/cozy13bt/contact?rev=1280283863&do=diff text/html 2011-09-19T23:38:51-04:00 http://www.lucubration.com/cozy13bt/cooling?rev=1316489931&do=diff Cooling is almost certainly going to be your #1 concern while flying. The rotary is capable of producing an enormous amount of power - far more than the Lycoming that the plans call for you to install. But power output is almost linearly related to heat generation, and unlike a pusher, the Cozy has no huge, fan-boosted front scoops with which to cool the engine. text/html 2010-08-05T00:57:08-04:00 http://www.lucubration.com/cozy13bt/design?rev=1280984228&do=diff I'll save the discussion for “Why a Rotary?” for others. The world doesn't need another preacher on a podium - there are plenty of others already doing enough preaching. I wrote this for readers who have already made up their minds to install a rotary. It is, however, worth some discussion of the particular choices I made during my installation. The first whiff of “This is not your father's Lyc-oldsmobile” comes when you start choosing major components like engine models, turbos, and so on.… text/html 2010-08-02T08:17:02-04:00 http://www.lucubration.com/cozy13bt/diagrams?rev=1280751422&do=diff Engine Stand Adapter This diagram illustrates where to attach the engine stand adapter. Depending on where you get it, it should bolt onto three or four studs on the left vertical edge of the front iron. Done right, the engine should be fairly balanced, and should stay in whatever orientation you spin it. Done wrong, it'll chop your hand off at the wrist the next time you pull out the locking pin! text/html 2010-08-19T12:30:43-04:00 http://www.lucubration.com/cozy13bt/disassembly?rev=1282235443&do=diff Before you begin, read Cleaning and check out my comment on the kiddie pool. Now would be a GREAT time to have one. Once you have your core you're going to want to tear it apart. This is basically a no-holds barred procedure. Very little does NOT get removed and disassembled, and provided you keep the parts you remove organized you could theoretically just tear into the engine at this point. But, if you have some patience to read on, I can share a few tricks that make the process faster and eas… text/html 2010-08-18T09:19:26-04:00 http://www.lucubration.com/cozy13bt/dispelling_myths?rev=1282137566&do=diff Before we begin, let me review some myths I encountered or even had myself, and found to be either false or misguided during my own build. It has fewer parts This one is my favorite because it's just so appallingly wrong. A typical Lycoming has basically 8 parts for each cylinder: the piston head, the rod, two oil rings, two valves, and two valve springs. Add in a crankshaft, heads, cam shafts, and a timing belt on the front cover, and you have a “core” parts count in the “low dozens” range.… text/html 2011-10-04T00:11:45-04:00 http://www.lucubration.com/cozy13bt/dynon?rev=1317701505&do=diff text/html 2011-11-28T22:32:42-04:00 http://www.lucubration.com/cozy13bt/ecu?rev=1322537562&do=diff I chose to install the Rotary Aviation EC3, and this guide is written for the latest version of that device at the time of this writing. The EC3 is relatively inexpensive, has dual, switchable computers for redundancy, and has a manual mixture knob - all helpful features for aviation use. As icing on the cake, Tracy Crook provides excellent support for builders and flies his own product, so he's constantly improving it. text/html 2011-10-01T12:56:38-04:00 http://www.lucubration.com/cozy13bt/fuel?rev=1317488198&do=diff The fuel system is a dual-feed, high-pressure configuration with two fuel pumps. A canister-style fuel filter feeds the fuel rail, and a vacuum-referenced bypass-style pressure regulator and tank selector solenoid send return fuel back to the source tank. An optional cross-feed feature allows fuel to be transferred between tanks for servicing, weight & balance, or fill-ups. text/html 2011-11-28T22:22:17-04:00 http://www.lucubration.com/cozy13bt/ingredients?rev=1322536937&do=diff For each of these parts I've listed a primary vendor and that vendor's part number for the item. However, many parts are available from multiple sources, including eBay. I'd encourage you to shop around to find the best prices and shipping rates. Many of these parts are expensive, and careful research could yield a 10%-20% cost savings for the whole project. text/html 2010-08-19T22:20:08-04:00 http://www.lucubration.com/cozy13bt/inspection?rev=1282270808&do=diff Tools Start by knowing your tools! The video below shows general usage for a dial caliper. If you don't have one of these, don't continue. In a race application you might be fine, but in an aircraft you HAVE to know that your parts are all within tolerances, or you could become a messy example to future builders! text/html 2011-09-06T21:30:18-04:00 http://www.lucubration.com/cozy13bt/intake?rev=1315359018&do=diff Stock Intake: Not Suitable The stock intake manifold is not a good choice for aircraft use. It consists of two large aluminum castings with a number of ports and runners for things like EGR that we don't need in an aircraft. This makes it both unnecessarily heavy and way too tall for use in a Cozy (and most other aircraft). text/html 2010-08-04T01:33:59-04:00 http://www.lucubration.com/cozy13bt/manuals?rev=1280900039&do=diff Factory Service Manual I'm not comfortable posting the manuals directly, but at the moment they're available for download from RX7Club. The most important document in the set is the FSM. I strongly recommend that you print it out and put it in a 3-ring binder for reference in the shop. Unlike what other automakers produce, it's not just a manual -- it's a step-by-step guide to doing a rotary engine teardown and rebuild. text/html 2010-10-05T22:39:45-04:00 http://www.lucubration.com/cozy13bt/mounting?rev=1286332785&do=diff text/html 2010-09-14T21:24:55-04:00 http://www.lucubration.com/cozy13bt/porting_and_mods?rev=1284513895&do=diff The bulk of these modifications should be made while the engine is fully disassembled. This will make it easier to fully clean up after any drilling or tapping that you do - metal chips are very bad for any engine! Porting I chose to not port my engine. There's plenty to do, and given that my model engine (John Slade's) has almost too MUCH power, I didn't think it was worth the risks to try to make more (I had this vision of not fully cleaning out any metal shavings/dust, and having my engine … text/html 2011-07-09T11:58:05-04:00 http://www.lucubration.com/cozy13bt/reassembly?rev=1310227085&do=diff Rotor Preparation The FSM lumps some reassembly preparation items into other sections of the guide, like Inspection, but I think the rotors deserve their own topic. First, slide an apex seal into each groove, and a side seal each side seal groove, to make sure they slide in smoothly. Note that you're not looking for any PLAY, but they shouldn't stick, either. Check the apex seal lengths with a digital caliper or micrometer, and their clearance within the slot with a feeler gauge. If they don't… text/html 2011-06-04T09:20:48-04:00 http://www.lucubration.com/cozy13bt/redrive_mounting?rev=1307193648&do=diff I chose to use Tracy Crook / Rotary Aviation's redrive, and I think this is the best option as long as Tracy keeps making them. It's reasonably priced, well manufactured, compact, and relatively light-weight. The only drawback to this unit is the mounting plate - or lack thereof. The RD-1B (the best choice for this engine) ships with a rear mounting plate but no engine mount. Further, Tracy's mounting plate puts the starter on the bottom of the engine. This might be fine for an RV (Tracy's plan… text/html 2010-09-14T21:05:18-04:00 http://www.lucubration.com/cozy13bt/resources?rev=1284512718&do=diff There are MANY sources of information about rotary engines, aviation, and rotary engines in aviation. This is not intended to be a complete list. However, I did find these resources very helpful and I would definitely recommend digging into them to provide supporting information for your project. text/html 2011-05-03T08:32:10-04:00 http://www.lucubration.com/cozy13bt/start?rev=1304425930&do=diff Introduction This site is a “recipe” that can help you install a Mazda Rotary engine in a Cozy MKIV aircraft. There are some excellent resources available online for rotor-heads and Cozy enthusiasts alike, but no consolidated how-to guides. That's the gap I'm trying to fill with this site: consolidating all of the information and guidance I relied on during my own install into one, organized, chronological guide to install a PARTICULAR engine configuration in a PARTICULAR aircraft. text/html 2011-05-26T14:40:02-04:00 http://www.lucubration.com/cozy13bt/techniques?rev=1306435202&do=diff Cutting Aluminum Wait, this ought to be easy, right? Aluminum is soft and easy to drill and bend. Why is this a topic? Now consider slicing an intake manifold in half. This is a 2” thick chunk of cast aluminum with the occasional steel freeze plug thrown in just to make things interesting. Or consider what I went through to mount my starter: I had to shift the starter and bolt holes 5mm to the side... in a piece of 1/2” thick solid aluminum. text/html 2010-08-02T07:53:57-04:00 http://www.lucubration.com/cozy13bt/videos?rev=1280750037&do=diff General Engine Operation There are many videos online that illustrate how the rotary works, but I particularly like this one. It illustrates how the major components fit together, and their functions. This next video gives you a sense of how the rotor positions and rotations relate between the eccentric shaft and the rotor itself. Again, nothing new, but most of the animation videos go so quickly it's hard to get the same sense that this one provides.