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yamaha 1200 genisis motor 120 hp 145#

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oahupilot

Well-Known Member
Joined
Aug 2, 2008
Messages
531
I have been poking around the internet looking for a new motor for my plane, not because i don't like vw 2180 but I wanted a more powerful and modern engine. I like the output of the rotax 912 but the cost is to high, same for jabiru, i could upgrade my 2180 but it would still fall short of some of the improvements I want, I was going to install a suzuki g13b but I would have to sell my 2180 to buy it. The sonerai really has a small window for weight and power requirements witch makes finding an engine a bit of a problem if you really do not want to mess with the original frame design. My intent was to find a motor that would not weigh more then 180# and would produce at least 100hp, in doing so I wouldn't take away from useful load or treed outside of design limits into the world of time consuming mods. I didn't want to modify my tail surfaces, add weight, or anything that would add time to the engine swap. I wanted fuel injection, electronic ignition control, dry sump, a modern all aluminum power plant with lots of power to preform inverted flight in, and i wanted it to be cheap of course. SO i stumbled across a post on a rotary forum of a guy who was modding yamaha snowmobile engines to run gyro copters and found the power plant i was looking for, the yamaha genesis 1200cc 4stroke. The genesis comes in at 145# wet weight with 120 hp that is without the psru but does include the starter, alternator, and engine accessories. They have manufactured a mounting/adapter plate to link a rotax c gearbox to the genesis motor, which is great since the rotax c box is tried and true and readily available. I think the entire package sounds great for our aircraft and the best part of all the first prototypes only cost 4000 dollars between the engine and all the extra parts!!! I am going to start emailing the guy that designed the first motor and get rolling on this swap. I think this new motor will put the sonerai in an entire new performance class even with full gross, and its cheaper then vw! Finally a high power engine with acro possibilities at a cheap price.

The down side is I do not think it will fit inside the stock cowling and i will be forced to change the lines of the nose. I really do love the look of the sonerai with but we will see how this all turns out, maybe it will have a nose more like a spitfire. Also i wont have dual ignition until i mod that into the engine as well, their will be coolant and plumbing issues to work out, engine mount brackets, and countless other issues to work out. Feel free to give me your input and thoughts on this project, I will try to post more info on this subject as it comes up. Also their maybe a 2180 cc vw engine up for sale with a slick mag, electric secondary, ellison throttle body, starter, alt, and prop: basically a full engine package if i find this Yamaha motor to be worth the hassle after more research.
 
sounds cool to me, i looked hard for a stronger motor also........inverted flight sounds cool to, what about a inverted oil system? the best of luck to you,will be watching for updates.
 
the engine is dry sump which is half the battle in my opinion in building an inverted oil system, the other halve just involves building and accumulator with either a nitrogen precharge or spring plate to maintain positive oil supply. Also a reversible oil breather/ pickup would need to be installed in the valve cover.
 
I just got a hard number on weight of the engine and a rough estimate on price for the genesis motor. Final wet weight was 152# while the cost will come in at 4000 dollars maybe less since I am having Todd skip alot of the work involved in modding the motor so I can do it myself. I talked with the Todd, the designer of the adapter plate for Yamaha motor, today over the phone and he is sending me some dimension on the parts and photos so I can kick around how I am going to mount it in a sonerai. once I figure out how I will install the engine I will go ahead and order the motor and begin fabricating the engine mounts to adapt it to a sonerai. A motor weighing in at 152# with 120 hp will be freaking awesome in a sonerai! I should be done installing the motor by April-May time frame. I will continue to post more info as it rolls down the line
 
The 1200 Yamaha does sound impressive on paper.it's very exciting. I have a Jabiru engine in my SII. It is rock solid. But flying it is a wild ride.
Be aware that with this new engine you will be doing engine development probably for several years. Some of the SUBARU POWERED aircraft in my area never really get out of the circuit. The cooling problems have not been solved.
My Sonerai descends better than 1000 fpm in a glide. You would have very few choices and little time when it quits.
I'm reminded that the airframe is built for 80 hp max. Your 100 hp engine may tear itself out of the fuselage.
I have said this before, "The Sonerai is a great plane when it is built according to the plans and operated within It's envelope. What you propose is IMHO going to require many design changes. I honestly think you should choose another design better suited to your intentions". The Extra 200 and even Epervier come to mind.
 
ya my first choice was an F-16 but the materials for that bugger was rocking..so after much deliberation i picked the soneria ;D
 
When I installed the 130 lb Jabiru engine in my SII, It was necessary to move the lighter engine forward 15" to correct the CG. The original empty weight was 629 lbs. After I put the Jabiru engine in it weighed 533 lbs.
So what you ask?
Well that 15" longer engine mount is covered in cowlings. The Sonerai II S was stretched aft say 15-18" to provide better directional (yaw) stability.
Now I have added 15" of engine compartment forward.
It would be nice if that just negated the stretched fuselage.
From flying the aircraft especially the first say 10 hours, I found that in straight and level and coordinated flight the aircraft displays neutral stability at best. However if you induce large roll inputs, or fly an uncoordinated turn the yaw stabilty becomes divergent or negative stability.
So I put a 30" Ventral Fin under the aft fuselage. It may help some. But I'm not sure. My flying skills have improved in the 30-40 hours I flew this summer. I find I can get the aircraft to do what I want within the flight envelope I have established for my 40 hours on type. It's hard to be certain of the effect of the fin, when you skill level is changing so rapidly.
All this is to say that if you put in a lighter engine, it may have to be placed forward, or you have to place say 55 lbs of ballast to correct for CG. If you move the engine location significantly your Sonerai will likely become a different aircraft to fly. MY S II has not been spun since the engine conversion. If fact I have not actually stalled it yet. It does stall at 65mph, in ground effect, during landing.
I hope you have every success with your aircraft.
 
IN response to building or buying something more suited to my purposes, I would have to say that anybody who ever bought/built a sonerai did so because that was already the most performance they could afford, if money was not an issue I would fly an edge 540, lazer, pits, a p-51, spitfire, su-27, well you get the idea. The sonerai is great plane for all intents of purposes when built according to plans for the money you have to spend, but the major limitations for me is flying two up on the under powered engine and the fact that a plane designed for +/-6g can't fly inverted just seems silly.
In regards to the engine tearing it's self out of the frame and the sonerai 80hp max limit, speaking as an engineer I find both of those to be a little misinformed. The forces present that act on the frame from the engine is torque, tension, and shear load. the shear load is actually less with the new motor while tension and torque are higher at the max output(their the same at 0 - 80 hp) of the engine, but the plane will experience torque roll long before the frame reaches its elastic limit. So no the engine will not rip itself out the frame, a good example off adding power to an airframe to increase performance is the ch-47d witch was up graded from two 3300 shp turbines to two 4200 shp turbines, the airframe can physically fly more weight then it can structurally support now. As for the max hp limit of 80hp(i think in my plans it could actually reach 100hp but not sure) that's really their more to ensure you do not exceed vne and get into trouble, an airframe will not break in straight and level flight below its vne just because it has more power. Another good example of planes upgraded with ridiculous power plant are the really tricked out super cubs that can hang off the prop at airshows, they are obviously running more power then "the max HP".
IN regards to cooling I guess I do not see that as a problem as the math for properly cooling the radiators will yield an adequate setup. I think alot of the problems homebuilders face when they divert from plans is they don't know how to run the numbers and fail to read into the heavy engineering books to learn how to properly calculate requirements; they just try to wing it. I encourage anybody to experiment and applaud them for their effort but I think their lack of knowledge holds them back from finishing the mods. Most people I know run away from any math higher then balancing their check book, so engineering books would hardly be something their interested.
regardless should be fun to see where this power plant leads, plus i still have my 2180cc so i can continue to fly until i am ready to swap in the motor. I wont make the swap until i know it works on paper then i will make the changes as required.
 
At the risk of steping on toes I would add to this discussion that the KR-2 flyers have made a lot of engine mods to the once docile plane.
Bill I know that the Jabaru is a great engine and a lot of Aussie Sonerai are using them are they all moving the engine forward 15"? It seems like a lot. As you say the length change of the fusalage makes it fly differently.
-Pete
 
If your in for experimentation, and you have the proper backround, a little creative thinking will never hurt anyone as long as saftey is observed. It sounds as if the basic design is done, which is 1/2 the battle. Be advised however that the budget and time predictions are likely to expand. Best of luck, measure twice, and fly safe.

Andrew
 
their is no doubt that time lines and budgets can/will change but thats the nice thing of paper, it doesn't cost anything to build on and if done properly will get you pretty in the ball park. I actually already experienced my first financial set back, late last night my car was broken into and some one stole my flight bag. So some one made off with my david clark x11 headset and I need to buy a new headset, thinking about a mach 1 in ear head set. I really am tempted to just buy another x11 set, i really liked that setup. What I am hoping is to find the guy who took off with my stuff so I can knock his brains out. The thing that upsets me the most is he made off with my e6b that belonged to my grandfather(who passed away from cancer), I can buy a new headset i can't replace my grandfathers e6b. My grandfather had some amazing aviation stories of what it was like to fly all over south America long before they had accurate sectionals of the area, the time before airspace controls, regulations, no xm weather, no gps, tis, asos, awos, vor, and the rest of the alphabet soup that comes along with flying today.

Back to the motor, 4000 dollars will get me the components; redrive, adapter, engine, radiator, ecu,wire harness, instrumentation, etc. After that I will probably scrounge the rest of my supplies from work, you know from the junk/scrap pile wink, wink. Allot of the hardware on my plane has been substituted with titanium were possible from the "scrap pile". The first goal is to work out an engine cradle to connect the stock Yamaha mounts to the engine mounts on the sonerai. Ultimately I don't want to change the length of the stock airframe by moving the engine forward, so i will probably move the battery around first and see where that lands me. At the moment I am waiting on dimensions for mount points, prop flange, overall dimensions, and cgs for all parts concerned. Once I have that I can start to work out how it will all come together on paper. As soon as I am done I will post up my findings written out with numbers to back them up for those who are curious. Sorry it wont be all cool and computerized on some FAE program it will be old school on paper with my crappy attempts at drawing shear-stress elements.

Pete-
No worries about stepping on toes here, anyone is free to say what they think just don't take it personal when some one disagrees with you. This is a forum, its meant for exchanging information and ideas, even if their wrong. I try to give very critical(but professional) response to questions and problems it is just my back ground and schooling, but nobody should take it personally.
 
This is strange. I just won on eBay a combo deal for a flight bag, e6b and DC ENC headset. I'm not kidding. But the auction ended a week ago and the guy is in Dallas so it can't be yours.

-Scott
 
I, for one, hope you make this project work. I've been noodling around with the idea of using a Yamaha Genesis engine in an airplane for a long time, but I was looking at using the motorcycle engine because of its integral gearbox. I finally decided that it was a project beyond my skills and wants, and I have serious doubts about the clutch basket surviving the experience. The snowmobile adaptation of the engine is likely a much better or at least doable approach.

If anybody makes sideways comments regarding the use of some Mickey Mouse grenade of a motorsickle engine, ignore them. Modern Japanese motorsport engines are the definition of durable. I've talked to folks who ran tests for Honda where an engine was run above redline (~14000 rpm) at full load for a week and no measurable wear occurred. I've personally witnessed a 600 cc Kawasaki that runs perfectly fine after months of rev limiter bouncing, miles long wheelies with the oil light on and at least 50 crashes at speed and bits of 2nd gear going who-knows-where in the engine (stunt bike).

Have fun and keep us posted.
 
oahupilot I have read most of the posts by Todd on the development of this engine, and the other two engines, the 80 hp 2 cyl and the 150 hp 4 cyl engine. What do you think in terms of his assesssment of the possibilities of increased resonance or unwanted harmonic vibrations using one of these internally reduced engines. For those that have not read the other forum posts, basically Todd has stated that since the 2 cyl and the 4 cyl contain an internal reduction drive for using a specific drive clutch that cannot take high rpms, he feels that these engines in their stock form may cause too many problems when a second reduction drive unit is added in order to bring the 8000 rpm max down to a prop rpm. Todd also feels that there is not enough good "meat" metal to fasten a reduction drive to on the engine. I feel like this part could be overcome with a little extra work, and so does Todd, but he did not want to invest the effort since the 3 cyl 120 hp was much easier to work out. This is also the engine he is preparing to make firewall forward assemblies and motor mount reduction drive kits and plans for.

My big concerns are the same for what I started running in to with my KR2, and the Sonerai seems to be faced with in a similar if not the same way: prop length for good prop efficiency, and the lowering of the thrust line due to the low mounting of the reduction drive unit in our application. If you look at the VW engine installation, and compare the thrust line location on the plans installation, and then take the upright installation of an inline motor, the reduction drive lowers the thrust line some 2 to 5 inches depending on the power plant of choice. I have been looking at the Geo/Suzuki, with Vassili & Raven redrives, the Hog Air twins, and the Yamaha engines both snowmobile sled engine, and my own V-star twin install. Only the belt drives that reach back up the face of the mount area to nearly the valve cover height restore the thrust line to where it is supposed to be by the plans, or close enough that I would not expect for big changes in aircraft performance due to thrust/power changes (i.e. big pitch changes due to power changes like those encountered with say an amphibian with high mounted engine).

I know that this is also not going to be met with enthusiasm, but I also want to prove the use of multiple blade props as being better performing in climb and not sacrificing crusie performance. I flight train pilots in the Cirrus Sr 20 and the SR 22, and Cirrus has virtually stopped delvering the engines with 2 bladed props on them in favor of the higher performing 3 bladed props. We get 500 to 750 fpm climb rates and 145 to 160 knots at cruise in the SR 20 with 200 hp engines and 3 bladed 74 inch props. I want to prove a 60 to 64 inch 3 bladed ground adjustable prop. I am afraid though that the only way that we can get that length on our Sonerai engines is to use a taller landing gear, and not sure what that might do to ground handling. I think it would help the full stall landing capability, and it would definitely change the taxi view!

Sorry for the long post, but hopefully most is appropriate for the thread. Thanks for reading guys.

Colin Rainey
Ormond Beach, FL.
 
Do you know of any good 3 blade props suitable for sonerais that won't break the bank?

Andrew
 
I intend to use an Ivoprop ground adjustable, 3 or 4 bladed prop, depending on the final thrust line height, 60 to 64 inches long. I also plan from day one to order a prop balancer and balance the prop completely before any serious engine testing and flying occurs. I can get away with running a composite prop though because I will not be running direct drive. I have only heard of two companies that ever made wooden props with 3 or 4 blades, and not sure if they still do. They are expensive at best, and may end up too heavy to run on a direct drive engine anyway. Evene the Corvair crwod is quickly going away from direct drive on the stock cranks and adding redrives or a 5th bearing assembly to take the loads from the prop and try to isolate the resonance. It keeps cracking the crankshaft just behind the first main bearing. I do not mean to imply that redrives don't have their own issues, just that I know about this one. Folks that are using bearings from axle housings and drive cases are having much better life than those who are trying to use bearings from other applications. The redrive being used for the Yamaha is a custom mounted Rotax C gear box with 3 to 1 ratio for a proven combination and reliability.

Colin
 
IN regards to the mounting brackets for the gearbox not having enough "meat", Todd is a shade tree mechanic/racecar builder/ hobbyist like most but holds little knowledge in regards to actual mechanical number crunching for structures. Todds adapter plates are machined from (not sure on the dimensions i think he said 1in) thick billet aluminum and are tied into various points along the way on the block, helping redistribute load, he has flown last I talked with him for over 70 hours on his prototype, and hasn't seen any failure points. Werther or not it will sooner or later i can not say I haven't look at the design to run numbers on it, something i will most definitely do before i mount the whole contraption to my plane. In regards to resonance i am not sure that is a real issue, both the autoflight and rotax gearboxes are designed to deal with such things.

The 2cyl engine didn't really apeal to me because its really not giving me anything my vw doesn't already, as for the 4cyl that was way more power then i wanted or was really practical due to vne/ prop size restrictions. The 3cyl had the proper power and weight package i wanted.

I want to keep the original thrust line so i don't develop any crazy attitude issues in the plane, i think i am gonna mount the engine sideways with gearbox in a crazy position to balance out the motor and maintain the original thrust line. Todd can machine the adapter plate to position the gearbox in any clock position you need, so this may work out. At the moment i am waiting on Todd to send me all the design info I need to start figuring out how I am gonna Peice this thing together. Once i get that info I will design the engine brackets/adapter to mount the engine to the stock x pattern on the soneria will in the proper position.

Also I intend to run a ground adjustable prop as well, not really sure who yet, but i will deal with that later. Really i just want the adjustable prop to play around with numbers and see what would be the best pitch.

well now that I have chanted enough sonerai blasphemy I will go hide in the arms room at work before the angry mob shows up to lynch me, their is plenty of room in here if you want to join me Colin.
 
Hello, Oahu. This is my first post here on this forum. I am wondering if you are able to rotate the engine as you were indicating as a possibility in your previous post. I am building a Little Wing with a VW redrive and am also working on getting my two place machine to run on the Yamaha. A Little wing is basically the Ultra Pup frame with Rotorblades instead of stationary wings. The problem for me is the same for you regarding the sonerai motor mounts and cowling. This engine appears to have the crank very low and the C box redrive only brings it up a little higher. I agree with the previous poster that sees a belt drive as the only design that has raised the prop back up where it was intended to be. I really hate to raise the engine way up and have all the "overhead" sticking up. Any new info? Watching here, and there for any progress on this powerplant.


I found your post and forum here just as you found the rotary forum. Looks like a lot of good information about VW's here.... Glad to see common problems and common interests. These Sonerai's have always interested me. James.
 
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