Cloud Dancer

Are you referring to the Lord mounts and snubber washers? I had to track some down for my airplane but I have no idea if my engine mount is a factory design or not since I didn't build it. This link will get you to the manufacturers home page and from there you can browse to the mount your in need of. Take the part number from there and then hunt around for a reasonable priced vendor. Most I contacted either wanted to secure a large order or had crazy high prices for small orders. Some tried to gouge me with the shipping. Link here: https://www.lord.com/products-and-solutions/vibration-and-motion-control/industrial/isolators

Since there are four holding my motor in the engine mount, I divided the total weight (engine, muffler carbs etc.) hanging off my Lord mounts by 4 and used that as a starting point to find a rubber with the load bearing capacity I needed. Then you get into the flex desired to weed out vibration and pick. I was toying with the idea of using a mix of two different density rubber compounds to help snub vibrations occurring from more than one engine setting such as one rubber  for idle and another for cruise rpm. You could stagger the different density mounts in a side to side pattern or a front to back pattern or a bilateral pattern depending on what vibration pattern, engine torque pattern or static weight distribution on the individual 4 mounts. I ended up getting 4 all the same but I may play with these if I have vibration or torque issues. If you think you have a bad mount it's best to replace them all. They do have a shelf life and if one's bad the others may not be far behind. Steer clear of used parts vendors or items listed as new old stock. The clock starts ticking the day these compounds are poured into the moulds. Fresh is best.

I'm sorry, the cold seizure was in reply to Turbo's question earlier in this thread. Your right about the rotary valve replacing reed valves but I thought the same shaft on the rotary valve ran the oil pump thus controlling it?

Our 582's are obsolete so we won't see a magic box from Rotax to bolt on and adjust the air/fuel/oil ratio under all temperatures and altitudes and make them bullet proof.

The Boondocker boxes are like putting a faucet in front of your faucet to control the water mixture going into your bathtub. Any change in the first faucet throws off any mapping you have programed in and screws up your desired temperature. I think there are far too many variables to make this kind of an approach feasible by anyone.

Back to Turbo's original thoughts, I think they are valid under a given set of constraints. A light built, lightly loaded Avid Flyer at sea level on a cool day will probably fly with a Rotax 337 up front. The performance will stink but it will probably fly. Put a 582 Rotax on there under the same circumstances and you have about double the horsepower to play with. An inflight adjustable propeller that is properly designed to tax his airplane's performance envelope for take off and cruise speed should see a benefit.

Try that with a heavy airplane with an extremely heavy load in the mountain elevations on a hot density altitude day and the Inflight prop becomes a waste of time and money. You have already burned up any margin of extra manageable horsepower needed to make the inflight propeller feasible.

Are you referring to all 2 stroke engines or just Rotax? Plenty of people idle 2 strokes for extended periods of time without any adverse effects. I've got an old 1950's vintage outboard engine that's spent hours on end idling while trolling for fish in the lakes of Minnesota. It hardly ever fouls a plug either! And it has a much higher ratio of oil to gas than our Rotax 582's are burning. There's got to be a little more to the story.

Didn't Rotax design the rotary valve to address this exact issue? Old two smokes do foul at low speed but the Rotax is supposed to reduce oil at lower speed to prevent this. As far as the temperature thing goes, your not going to seize an engine from cold seizure if it's been running sustained at a given speed long enough to insure all the engine components are evenly heated. That's the whole point of having a water cooled engine. The thermostat if setup properly should regulate the engine temperature at all speeds. Anyone that's driven a snowmobile can attest to the fact that a 2 smoke engine will run at any speed since they are almost never run at one speed in a sled. The old 2 smokes in sleds hated three things, idling for too long, running wide open for too long or getting your oil mix wrong. Everyone I rode with carried an extra set of plugs to fix the first problem  of idling too long. We all carried a tow rope to fix the other two problems.

Granted the limiting factor may have more to do with the carburetor being  jetted for just two ranges. Idling and  cruise speed in our case. Any speed in between these two points is an area that changes the air/fuel ratio to a point other than optimal. The rotary valve for oil mixture knows nothing about these settings in between and therefore cannot feed the right oil under all conditions. Until they start putting oxygen sensors on these engines and incorporate an oil injection and fuel injection systems that can ebb and flow with the numbers coming from an oxygen sensor and the various temperature sensors this debate will never end. I say the two stroke still has room for improvement. With engine design improvement I think the in flight adjustable prop would be very practical. Like most things, no simple solution since the problem itself isn't simple.

I got a couple of sets of struts off a Taylorcraft a couple of weeks ago for free. They look just fine and that's the rub. The A&P that gave them to me said the service life was up on them so he replaced them with new. He said you can have them X-rayed to keep them flying but they charge you $400.00 dollars just to X-ray them. We run into the same problem with our struts once they are complete; there's no cheap and easy way to tell if they haven't been compromised by the elements over time.

The purpose of this post is to help a YouTube guy I subscribe to. Link here for RPM gauge/Balancer he's designed: https://www.youtube.com/watch?v=fzcXJIGZSHA&t=43s

This thing he's built is very cheap to make and could be used for many applications. Some applications I think it could be adapted for are dynamic propeller balancing. Crankshaft balancing. A method to dynamically balance your tires while on the car. It could be used to develop a spindle run out indicator for a cnc lathe or mill.

Please check out his many videos and subscribe to help support him if you like his stuff. He puts a lot of time into developing his projects and I noticed nobody seems to know his stuff exists judging by the  low number of views and comments under his videos. I'd like to see guys like this promoted on YouTube rather than the social crap that does little to expand ones mind.

Pass the link on to anyone you can think of that's interested in tinkering with home brew solutions with real world applications.

Since the ceramic is a glass it has two properties that prevent it from being an ideal candidate for muffler use. Glass is a great insulator and it does not flex well. When you bond it to metal on a muffler your asking two different materials to expand and contract at the same rate. Then throw in the hammer effect these mufflers get from vibration and the glass may not fair so well. I've got some very expensive high temperature paint covering the  exhaust manifold on my Austin Healey car. It's basically powered glass added to a binder to get it to stick. It looks nice but i have no idea how long it will hold up. The metal on the cars exhaust manifold is much thicker than my Rotax exhaust so the expansion rate will be slower. And the car engine does not vibrate like my Rotax exhaust. I've had my share of broken mufflers, broken muffler springs and broken muffler ball joints. Almost always they seem to be vibration/heat related. How many old antique pots and pans have you seen with chips out of the ceramic coating? Most are probably from rough handling which again brings me back to the vibration of a Rotax exhaust. The Kaowool you suggested is a far more flexible substrate than a brittle enamel coating painted on.

If you apply Kaowool to the exhaust manifold and the muffler it will work great for keeping the heat away from items around the exhaust. I question if this heat being retained by the exhaust components is a good thing? With exhaust gas temperatures above your recommended 1100 degrees to stress relieve the muffler and insulation to insure this heat stays within the exhaust components, it seems the muffler would stress relieve itself just from being run to temperature and allowed to cool down after flight. I'm in agreement that stress relief is a good thing, I'm not so sure that constant stress relief is a good thing  as metal at high temperature is not as strong as metal at a cooler temperature. Until Rotax either supplies insulating muffler tape or at least endorses it I'll remain on the sidelines and see how the game unfolds.

It's far from a simple question.

It will stink until it's been run awhile but you can paint it with flat black paint designed for wood burner stoves. I've got an old wood burner from the  early 70's that's green enamel but that type of coating is  basically glass and won't hold up to vibration.

I should point out that when I say enamel I am not referring to house or car paint but to the powdered glass you see on kitchen sinks and metal bath tubs. Also used on ovens, washers and dryers from the past.

Link here to enamel description: https://en.wikipedia.org/wiki/Vitreous_enamel  My father was a watchmaker and a jeweler and in the jewelry trade many of the colored pieces are referred to as enamelware.

Is this a pressed together crankshaft? I have a Yamaha engine in my jet ski that was a two piece crank. I purchased just the half I needed replaced and my local snowmobile repair shop took the old one apart and pressed the new part in place. It's common practice in many of the sled engines.

Here's a link to a home brew electric in a R1 Yamaha cycle. I still like the idea of almost instant thrust reversal without the complicated propeller. I have a race nut friend who loves horsepower but hates the idea of an engine with no noise. A quiet motor sounds like an advantage to me.

Link: https://www.youtube.com/watch?v=vdKDOfXBRMM

A great read, too bad we don't have all the flyers produced since the early days...

Thanks for the files.

That's a little over kill don't you think? It would be fun though. I was thinking a slightly smaller engine and just enough battery to win the race. Maybe one of the motorcycle engines is more adaptable to our sized airplanes. Anyone else follow the races on The Isle of Man? We started out strong the first couple of years with U.S. entries making it to the top of the field but we have since failed to make the leader  board. Link here: http://lightningmotorcycle.com/

That's a much longer motorcycle race than the one were talking about for this airplane event so less batteries would be required.

I'm still unclear as to the failure? I don't have my airplane handy to make sense out of the photos. Did it break exactly at the splice? In other words was that two walls of tubing that failed or just the inner wall that failed at a splice point? If it's the latter of the two I don't think I would rely on a weaker turned down piece of tubing to fix it. It it is the latter I'd have turned down a piece of solid stock to fit instead of the tubing. The load would be mostly torsional in this application and a piece of solid stock would take much longer to fail in a corrosive environment. You have plenty of surface for bonding on the turned down part in your photo but the weak part would be the shoulder where the lathe work began.

There looks to be an aluminum colored substance on your ribs, is it paint or maybe a Polyfiber UV protection? Whatever it is, it will probably need to be removed to get any kind of epoxy or glue to bond to the wood underneath. Someone else on this forum might want to chime in on this?

It may be easier to turn a 70" prop into a 68" prop if needed as prop stretchers are in short supply. Depending on the make and model; you might be able to shorten a prop down the road. Just something to think about before forking out huge chunks of cash on something that probably cannot be returned for a refund.

To get the most horsepower per pound I'm thinking electric is the way to go if all you want to do is win this style of race. You won't have the range of an internal combustion engine but it's hard to argue against electric in this application. It would have the ability to instantly reverse thrust giving you the same advantage as Draco in that department.

Have you seen this aviation speed record attempt: https://newatlas.com/rolls-royce-electric-airplane-fastest/57849/

The motorcycle world has already been turned upside down with the advances in electrics such as this: http://lightningmotorcycle.com/

And how about this electric China has in the works for cars: https://www.forbes.com/sites/neilwinton/2016/11/21/chinas-nextev-launches-nio-brand-and-worlds-fastest-electric-car/#5bc859042969

They are just checking your pucker factor as anyone that's to be a pilot will need a little more than most from time to time.

Is the Hirth gear box that much stronger than the Rotax gear box? The prop manufacturer usually know how to get the most out of their props on a given horsepower and range of speed desired; I'm wondering if they run this by Hirth before recommending it? If so I'd say it should climb like a home sick angel.

For those wanting a link to this and other great videos John has provided try this: https://www.youtube.com/channel/UCRoNYolIG9YAu_vGhGLkzeA

You might have a market on this forum for those if you ever decide to start molding them out of fiberglass or carbon fiber.

Maybe it was bending, but those fittings are designed to withstand a side load within reason. See the first link I included in my comment above to the vendor and angle deviation information is listed under the part specs. That number will give you a starting point if side load was a factor or not. If the side load can deviate beyond the manufacturer specification I'd say it's either a design flaw or failure by the builder to build the linkage according to print. That's if it failure of the part occurred in flight and was not a result of the crash or lever abuse. All bets are off until we can rule out everything else as the cause of the crash. I did not read any official crash investigation yet.

I browsed the load specs for various versions of Heims rod ends from a vendor. Even the cheapest imported version has such high failure specs. in pounds I can only see a slight chance that it was the part at fault. If it failed in the jam nut location it's more likely the failure was caused by over torquing the jam nut causing stretching of the thread in that area and weakening it. A link to the vendor page I browsed here: https://www.fkrodends.com/products/rod-ends/

Remember that bridge that collapsed in Florida last year? A You Tuber I follow did a couple of videos on this and the mass consensus was Post tension failure. That's a possible explanation of how a rod end could fail if the jam nut was over torqued. A link to Ave's video here with a warning for adult language: https://www.youtube.com/watch?v=KtiTm2dKLgU

As one person commented rolled threads are stronger than cut threads; I'm going to add generally this is true. You can screw up rolled threads during manufacturing too! I've made hundreds of thousands of threaded parts in my life time both rolled and cut. A properly cut or rolled thread will each perform to the  task it was designed for. It was also mentioned a rolled thread costs more. I can't understand this. Maybe if they don't have a roll threader head for their cnc and need to send the part out or run the threading operation on a separate machine would this increase the cost. Roll threading is faster and more efficient in the long run but many of the younger cnc guys have never been exposed to this technology. And it was mentioned the threads were not centered. Very hard to produce off centered threads on a lathe and almost impossible to produce them off centered with a roll threader head. But that's the male end I'm talking about. The female end is another story. Locating a cast or forged part in a fixture so the hole for the thread is centered every time is impossible given no two forgings or castings are the same. Who ever mentioned rolled threads did not mention if the threads were internal, external or both. There are rolled taps to produce rolled internal threads also. The tolerances needed for the hole for a rolled internal thread are something most younger machinists don't understand and you end up with a high cost factor due to operator error with screwed up parts and broken taps.

That's my two cents worth; if we look at this problem from enough perspectives were going to get a whole dollars worth sooner or later.

This is not a V configuration engine so why would you make such a statement? There is no way they are using a conventional crank within an opposed cylinder configuration so not the same bearings either. Plenty of torque in engines with the cubic inch size, and stroke length at low rpm.

I'm not looking for a C65 engine, I'm looking for an engine that has a ton of after market developers already and a format that makes it attractive for new vendors to want to get in the game. If it catches on and performs, then they may want to get their parts certified to appeal to the general aviation field but it's not worth the hassle until it's been proven in the experimental end of the spectrum.

Take a walk through the EAA Pioneer Airport hangers sometime and you will get an idea what size piston and stroke has been successful in the past to produce low rpm engines. At one time there were other engines besides Continental and Lycoming. Were not trying to reinvent the wheel here. Were not shooting for great fuel economy. We just want simple and dependable within a weight our airplanes can carry without robbing them of all their performance. Meet the basic goals and let the aftermarket vendors tweak it from there to improve it.

As far as overheating issues go, name an engine that has not run into this problem in some application or another. The 582 being water cooled even suffers from over heating issues. The C65 has heating issues too when heat issues are not addressed properly. The C65 is a good engine; just not a good fit for our small airplanes.

For those reading this thread; here's a link for the official requirements to manufacture your own certified lights or any other part of an airplane. Link here. https://www.faa.gov/aircraft/air_cert/design_approvals/media/CPI_guide.pdf

I thought I'd put this subject to an end. It's a 105 page read but it's clear to me that anyone wanting to get a new product to market has a path. It only makes sense since every airplane and part on those airplanes started out at some point as a non certified part or airplane. Many of those small shops I built certified government parts at had the owner of the company doing it all. No diploma hanging on their walls saying they were certified designers or inspectors etc. They were hands on build it guys like most of us in the experimental world. In other words, it's not magic.