This is Steve Henrys engine install. He has a littlw over 60 hours on it. He reports it has as much power as a big bore 912 with a turbo. He recently installed the rk400 clutch and seems to be working good for him.
dholly, I don't understand your question. This is a dyno run of the engine for any application. It is raw torque and RPM numbers with the engine bolted to a dynometer. what is a "Aircraft application dyno chart" could you possibly be asking for real world numbers as far as airspeeds and rpms for a given airframe with this engine? If so what numbers would you like to see? I have a little bit of data of this engine flying in Steve Henrys Highlander and a number of different trikes and gyocopters. Just in general Steve is able to climb at a steady 1900 fpm from 1000msl. his WOT level flight is 124 MPH with the 3:1 ratio gearbox and slightly faster with the 3.47 ratio. He takes off in less than 100ft. In comparison to the his past big bore 912s with nitrous the stock RX1 pulls harder on a pull scale and pulls harder on takeoff. Static thrust pulls were 580-600 lbs depending on the day. Those pulls were with a 80" X 46" Prince p-tip prop. Both highlanders weighed right at 700 lbs. I hope this info helps but If there are any other aircraft data points that you are looking at, let me know and I may have them.
As a update to Steve Henry's highlander RX1. He is replacing the header for one that has longer primary pipes so he has better low end power and better throttle response. He is having trouble making spot landings for competition purposes. I have been using a different header here lately and it really changes the low end torque. Wide open power is stiil about the same.
Steve Henry has gotten a few hours on his machine. He is pretty pleased with the performance so far here. So far he reports its performing comparative to his 914 that he had larger bore cylinders. here is a couple pictures.
No, I was just saying there are a lot of options for 70 inch props out that will work on the RX-1. I would suggest if using a 2 blade run the 2.62:1 ratio and a 3 blade use the 3:1 ratio. Steve Henry is using the 3.47:1 with his 80 inch prop. But remembee for those out there calculating tip speeds and effiecencies. The RX-1 has a 1.19:1 built into it. So for example the 3.47:1 is really 4.13:1 from prop to engine.
Steve Henry made his first flight with his RX-1 powered Highlander. First impressions are really good. He reports a stronger feeling of acceleration on take off. No testing yet as far as takeoff distances and climb rates. He has only made one flight so far but as numbers goes here is the numbers in comparing static runs between his 912s with 88mm pistons (aprx. 115 HP). The 912 used a 80 inch diam. X 42 inch pitch propeller, he was able to turn it 2180 RPM on the prop staic. The RX-1 engine is turning a 80 inch diam. X 46 Inch !!!! and it is turning 2180 RPM static. He believes his 912s with larger bores was closer to 120 HP and the RX-1 is definitely doing more work. More to come on climb rates and take off distances. As far as HP for the Kitfox it's definitely more than it needs but I don't think it will necessarily be over powered. That's kind of like a girl to pretty.....
The 4 cyl. Is a bit longer but it is practically the same weight. I'm not a resident expert on the 3 cyl. But I'm told it has a heavier crank shaft aND it runs a balance shaft along beside the crank. The 4 cyl. Is really smooth without a balance shaft. The rx1 or 4 cyl. Weighs 128 lbs. With no carbs or exhaust. Steve Henry's engine in the above video was only firing 3 cyl. I spoke with him and he said #2 cylinder carb. Had a plugged idle jet. So it will sound much smoother when he is done. And I don't know of a easy way to add a second ignition but I do agree that these ignition are super reliable.
Are you sure your not confusing the apex engine with rx1. The only limp mode I found was with throtle overide and that is easily bypassed. The gearbox is slanted to bring the center of the prop. To the center of mass and engine mounts. It's 9 inches from the center of hub top most of engine. If the gearbox was straight up it would only gain about 3/4 inch. My kitfox cowl is round and looks like it will fit just fine.
Oh and as far as flying a trike with the 912uls and the RX1, You can feel the acceleration and take off performance increase but trike's can not use that much power unless you have a really fast wing. So you end up not holding the throttle very long because you end up heading straight up in the air. Its a lot of fun but I look forward to seeing how fast it will launch a kitfox off the ground.
To answer some questions: 1) The adapter kit is $1500 and includes the adapter and hardware to mount a C gearbox. 2)The cost engines just depends. I have found that it is best to find low mileage good shape snowmobiles and buy them complete. They sell for $3000-$4000. I personally have bought some for $1800. 3) So another question that hasn't appeared here but I would like to hit on is complete cost for a FWF package one will be into one of these engines. Now I'm not offering packages since I do not have a business nor the time to offer this kind of service I am just offering my experience with the cost so someone can make a better educated decision on whether this engine is right for them. $1500 for adapter kit, $3500 for snowmobile, $1600 for new Rotax C gearbox plus say $1000 for nice AN fittings, Bottles, radiator etc. So your at a conservative $7600 for a 140hp engine package. Now for a lot of people this will come cheaper for instance they already have a used gearbox or they find a sled locally for $1800. For many it may make more sense to keep a look out for the used 912 for around that price. For me I love having a modern 4 stroke that has more HP and is cheaper to maintain and buy parts easier. 4) The 140HP is at 10,000 RPM. Now the engine has a built in reduction of 1.19:1 and I have been either using the 2.62:1 or the 3:1 on my trikes depending on what propeller I use. I plan on using a 3:1 on my kitfox spinning a 74" prince P tip. Another fellow building a Highlander is using a 3.47:1 spinning a 80" prop. For everyone's calculation purposes here is the ratios for the engine to prop with the available rotax gearbox ratios (1.19 engine ratio) : 2.62:1 = 3.12:1 3.0:1=3.57:1 3.47:1=4.13:1 and 4:1= 4.76:1 5) I have done lots of thrust measuring. I have pulled pretty regularly 530lbs. I have pulled 570 lbs with the prince P tip 74". and the 3.47 rotax gearbox. I do believe there is more to be had since it sounded like the prop was cavitating. in comparison my 912UL kitfox pulls 320lbs and my buddys STOL plane with a 160 hp 0-320 Lycoming pulls 590lbs all pulls on the same day.