After having some support from you, I will go ahead and post some info about the engine. I will try to make this post as short as possible but with a little more technical details.
The Cors-Air engine is manufactured by JPX Italia. First of all, this is not the French JPX engine. The name JPX comes from the fact that the company used to be a JPX distributor. Because they were not very happy whith the JPX engine, they designed a totally new model, their own and since the company has been known as JPX for a long time, for fiscal reasons, they did not change their name.
Two stoke, air cooled, 175,5 cc, 21 HP at 7,200 RPM.Compression ratio: 11:1
Cylinder, piston, connecting rod etc.: The cylinder and the head are made of two different alloys that allow a more even heat dissipation. The cylinder walls are NICASIL or Cermetal coated. The bearings on the connecting rod are high performance silver plated roller bearings like those used in racing engines. The connecting rod is steel Ni Cr Mo and copper plated.The "honing marks" on the cylinder head are deeper and have a different than the "usual" pattern. JPX Italia told me this pattern is used in racing engines and prevents overheating and seizures during the run-in period.
Fuel system: The fuel tank has a special valve that allows the tank to be pressurized (by the gasoline vapors) thus allows a much better fuel feeding.The carburetor is "my baby" the Walbro 32 which amazingly enough, works perfectly with this engine. It is not as sensitive to tuning like on my Fly 115/3 with the Solo 210. It is partially caused by the initially pressurized fuel in the tank, also by the "reed valve" feeding system ( the carb is connected to the crank case and has reed valves) and finally because of the 6
(yes 6) ports in the cylinder that feed the mixture from the crank case. Of course these ports also cause a much better carburation than on the Solo. In conclusion the "very peculiar" Walbro 32 works amazingly well, almost like the BING carb!
Electrical system: The engine has electonic ignition with a double spark per stroke and the timing is electronically regulated according to the RPM. There is a special alternator (similar like the Fresh Breeze has) which charges the battery in flight.
The electonic spark system generates a weak spark at 50-60 RPM! At 1,5 revolutions per second ( 90 RPM) I could get a very good spark!! The regular Solo 210 needs around 600 RPM to generate a spark. As I was informed by one very competent DK GURU, the DK needs about 200 RPM.
This is one of the causes that the Cors-Air is guaranteed to start up at the first "push" every time, cold or hot.
Even in 15F after priming the Walbro, the engine fires up immediately. Not to get into too many details, I would like to point out that there are other causes that this engine starts up so easily: reed valve system, specially ported cylinder.
Because of the very good ignition, and timing, the engine idles very smoothly even at 1,600 RPM! No more shaking!
It refers to the warm engine. When the engine is cold, like any engine, it will run rougher until it warms up.
There is NO HAND START on this engine at ALL! ( some people do not like electric starts but this is the only option here)
There is no internal or external decompression system because the electric starter is enough. It is the same starter used on Fly Products, Adventure etc..
The engine is very strongly built: it was designed for aviation. It can support 11,000 RPM.
The maximum RPM achievable with the 90 cm propeller that my Tornado has, will be 7,400 after the engine is completely broken- in. Therefore this engine has a huge safety margin, 11,000 versus 7,400 RPM.
The engine is not upright or inverted. At first it looked weird. I have never seen something like this before.The reason for tilting the engine to the left (looking from behind) was: to partially compensate for torque effect and partially balance the very elaborate tuned exhaust system (see picture). It also provides a better cooling ( according to JPX Italia )
Engine attachment to the frame: there are 5 (five) rubber mounts that securely hold the engine. Four behind the back of the pilot and the fifth one, under the reduction, in the back. This system that I have never seen before, absorbs the vibrations very well. The fifth mount also transmits and helps to dissipate the vibrations more evenly in the frame. I say frame, because there is no separate engine frame and propeller cage. It is a strong stainless-steel integrated system.
I could not resist to wait until I get to 10 tach hours and I opened the engine after 8.
Although the manufacturer claims that the engine can be safely flown by an average technically skilled pilot after 2 hours of running in on the ground, I waited longer. You know me... just in case....
Anyway, when I opened the head and looked into the cylinder I was expecting to see some minor scratches that I always find in other brands of engines. I found NONE! Looking at the opened cylinder I noticed there was no gasket!? Then I saw a tiny black ring imbedded in the cylinder head. Believe it or not, it was an O ring. I was even more intrigued when I found in the specs that the torque needed for the four cylinder head bolts is only 1,8 Kg.m = 18Nm.The seal or O ring is made of a special heat resistant polymer and it turns out to be very cheap! The manufacturer recommends to change the seal every time the head is removed.
I had no O ring and called JPX Italia asking what to do. They told me that the engine should be open only after 50-60 hours and it was made to be flown not to be tinkered with. I just used my little trick with the antiseize compound and it worked. However JPX Italia told me two new O rings will be sent immediately at no charge. This was nice. They know that I am the first Cors-Air owner in US and told me they have any parts in stock.
Exhaust system: fully tuned pipe with a very efficient and beautiful muffler. (see pictures)
The engine is very quite at idle, comparable with the new Fly 115/3, quieter than the DK but a little louder than the Top 80.
As soon as the RPM increase the small 90 cm propeller noise takes over. At 7,000 RPM it is loud and can be compared to an Adventure F2. The thrust of this propeller is amazingly big though. At 7,000 RPM I can hardly hold the unit on the ground. I did not measure the static thrust ( these are only preliminary tests). I am working on a new device with a scale for thrust measurements.
I really believe that at 7,400 RPM the thrust will really be much greater.
I can live with this propeller noise. The unit is more compact than my Fly 115/3 and definitely more powerful in spite of the 25 cm difference between the two propellers.Besides, other types of propellers can be also used.
Overheating problems: Many of you, in your off-forum letters asked this question. The tuned pipes usually cause an overheating tendency. This is why some manufacturers beef-up their engines with heavy and oversized cylinder heads, adding more weight.
With the tuned exhaust this engine does not exhibit overheating tendencies after 3-4 hours, although at this early stage it is not recommended to use full power for longer periods (like on any engine)
Measured cylinder head temperatures: idle at 1,600 RPM, below 200F. Idle (the way I set it) at 2,200 RPM is 200F
Mid-range operating temperature at 4,500-5,500 RPM 280F. High RPM range temp. at over 6,700 RPM is 330F. Over 7,000 RPM temperature- not tested yet.
The engine maintains these temperature ranges (shown above) for very long times. ( Tests not completely finished)
Tornado frame: Stainless-steel integral cage ( engine frame and propeller cage integrated), very low attachment points. They allowed me to do larger radius turns with weight shift only. Stability in flight, very good. (but this is relative since there were only slight bumps like #2 in a 10 degree scale (according to Jeff Goin)
Harness Sup-Air. Comfort: MISERABLE!!! The harness is too small for me. It is a medium. I ordered a medium but bundled up in the winter, I need an XX Large. It is on its way from Spain. AIRFER are very nice people and with no problem they offered to send a bigger harness at no extra cost. (of course I will have to return the one I have)
Stability of the Tornnado on the ground: excellent. It is hard to tip it over!
Weight of entire paramotor: 54 Lbs with no harness and fuel. It is lighter than my Fly 115/3 which is very heavy because of all the additional gadgets I installed on it.
Conclusion: The Cors-Air exhibits outstanding reliability. No tinkering needed. (as you know me, I like to tinker a lot and I still like my Fly 115) The bottom line is that this engine is far superior to "other engines" I know. No names here. It is a very strong and
maintenance free engine. Of course it is too early to "sanctify"it but from the way it starts up (hot or cold), the way it runs and feels, from the incredible power it delivers, I can tell now that this engine belongs to a totally new generation. It is not heavier than the "most commonly used" engine (no names). It is made from superior materials, burns less than a gallon an hour in normal conditions.
The Tornado is a good design. Of course stainless steel is a little heavier. But it is stronger and less prone to scratches than aluminum.There are other options here too. A titanium frame would be much lighter and stronger. I was told that the Tornado can be used for tandem flights by light pilots. AIRFER tested it with a 195 Kg payload
( two light pilots) and it climbed very slowly but run at full power for one hour until they ran out of fuel and landed safely on the beach.
In my opinion for tandem flights one should use the bigger brother, AIRFER BIMAX which delivers 68 kg of thrust with the Cors-Air engine equipped with a 120 cm propeller. The climb rate of this unit is an average of 2 m/s (tandem)
As I pointed out earlier, these are only preliminary test results.
There are many other details that I did not mention. (this post is getting ridiculously long and boring)
I apologize for used space.
If you have any questions and if you consider this subject worth to be continued, I will do my best to answer them.Please post all the questions on the forum. It will be easier fro me to answer.
Thank you Scott Fisher for offering your web site for eventual further information regarding this subject.