UL Option

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Re: UL Option

Post by danweseman »


Since no others have responded to this i will chime in. Also I may wander off the UL topic a bit
With respect to wanting substantially better performance than your Sonex, I suggest 160+hp "class" engine. I say "Class" because all engines are not a direct comparison in actual performance. The UL line is very light weight and is getting a reputation for reliability. They are rated at a much higher RPM (3300 RPM) than traditional aircraft engines (around 2700 RPM). Choice of props is critical to getting the most out of any engine, but more so with the higher RPM ULs. To get the most out of the UL the airmaster CS prop would be great , but it adds 10 k to the package?
We have about 5 UL powered aircraft under construction and only one is a 520 IS. I would not go with a 390 for several reasons (to long to go into...) The 520 will work nice and covers the points you mention. The biggest down side will be the installation . We have cowls and engine mounts , but the rest will be up to you to figure out. Ray with UL will help in any way he can, just understand it is not "plug and play". The lycoming and Corvair installs are not plug and play either, but many examples are flying well so its easier to follow a proven path.
The cost for a UL520 ISA with dual fuel pumps and computers is getting pretty high. But if a 40K+ (depending on prop) firewall forward is in your budget it may be a great choice.
Another great other option is a TItan 340. It can be configured with many induction and ignition systems from carb/mag, mechanical fuel injection/ EI, all the way to true FADEC EFI II system. It will be slightly heavier than a 520ISA. It has a much lower torque curve and many good propeller options. I think it will be hard to beat a 180 hp 340 for all out performance.I would love to get my hands on a Panther with a 0-340 and a Whirlwind RV 200 CS prop on it. I would also love to fly a UL 520 ISA powered Panther with a AIrmaster CS prop. SOooo. you guys get building and let me fly them....
For sport aerobatics , and sport/cross country work you describe, all engines will work well form a CG standpoint. At this point 75 % of the panther Acro fleet time is with standard lycoming 0-320s and they are all a joy to fly. Your light weight (sub 180lbs with chute) will work well with any of the engines.
Based on what we see reported in other aircraft a UL520 with a well matched prop should be very close to performance a 180 hp 340.
In closing SPA has OEMS with all the major engine manufacturers, so can we can help you decide on and spec the engine out to best fit your Panther. You can read that " I sell all the above engines and make a little bit on each of them so my opinion is not based on sales"
Dan Weseman
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Panther 515XP

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UL Option

Post by mtl767 »

Hello Everyone,

I’m Panther builder 101, located in Southern California. Tail kit completed and preparing to start rear fuselage when shipment arrives. This is my first solo build. I’ve helped my father build a SONEX kit with a jabiru 3300, completed in 2016, now mine, hangared at KWHP. I’m not very satisfied with the performance of the Jabiru/Sonex combination. Climb performance on take off varies, about 900-1200 fpm which rapidly degrades during climb, even to moderate altitudes. I have to closely monitor EGT’s/CHT’s during the hot months. I’m hoping for at least twice the performance with the Panther. I’ve been flying since 17 years old, Navy and airlines. Almost all turbine time. I’m still a newbie with recip engines.

My mission for the Panther:
1. Commute from So Cal over the Sierra mountains to the Reno area. I’m aiming for performance in both speed and climb performance to 12,000+ feet.
2. Aerobatics. I’d like to have some limited inverted ability.

Looking ahead at engine choices, considering UL 350, 390 or 520 series. They have a weight to horsepower ratio of 1.3 pounds per horse power, and are FADEC, which appeals to me.

Has anyone installed, or planing for a UL engine on the Panther? Has anyone considered a UL and decided to go with another choice? If so, why?

Budget is not a main driver on engine choice. My thoughts are, the money spent on quality and reliability can be somewhat recouped down the road by selling off the engine when I’m done with the Panther.

Right now, areas of interest for me regarding engine choice are, engine weight vs horse power, handling characteristics, and ease of installation.
1. Considering my goals, what is the ideal trade-off in performance and weight? I weigh 155lbs without a chute.
2. How will the Panther handle acrobatically with a heavier engine vs a lighter engine?

I’d appreciate hearing from folks about their engine of choice, the handling characteristics, and performance numbers you're seeing in climb and cruise. This would surely help me focus-in on what engine will be best for my mission.

All input is appreciated.


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