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Current builders planning to use a UL Power engine?

S

SonexGuy

Well Known Member
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It's been 2-1/2 years since I asked who, if anyone, was installing or planning to install a UL Power engine, so I thought I'd ask again. I have all my FWF accessories on hand for the UL Power 520iSA engine, so I'm laying out the firewall on my RV-7. I'll be running dual ECUs with dual batteries. I'll be ordering the engine and cowl later this year (8 week lead time).

I flew an RV-7 with the 520iSA last year and had a blast with it.

Anyone else?
 
SonexGuy said:
It's been 2-1/2 years since I asked who, if anyone, was installing or planning to install a UL Power engine, so I thought I'd ask again. I have all my FWF accessories on hand for the UL Power 520iSA engine, so I'm laying out the firewall on my RV-7. I'll be running dual ECUs with dual batteries. I'll be ordering the engine and cowl later this year (8 week lead time).

I flew an RV-7 with the 520iSA last year and had a blast with it.

Anyone else?
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I'd urge you to contact Mark Marino at Hangar 10 Aero ([email protected]), since he has installed UL Power engines in various aircraft, including a RV-12, and is familiar with the quirks involved in getting the ECU system to play nice.
 
Not currently, but I've considered it to replace my O-320 when it's worn out (long way to go on that). I flew behind a 350iS when I did a demo flight in a Zenith 750, I was really impressed with how smooth and quiet it was. My biggest concern with any of the European developed engines is that they're primarily designed for unleaded gas, which is hard to come by at airports in the US. They will run on 100LL, but I've heard from numerous operators (and the manufacturers manuals) that running leaded fuel shortens maintenance intervals and can cause a variety of issues over time.
Just out of curiosity, who's designing the FWF for the UL installation? Is the mount elongated to move the engine forward for CG?
 
lucas2696 said:
Not currently, but I've considered it to replace my O-320 when it's worn out (long way to go on that). I flew behind a 350iS when I did a demo flight in a Zenith 750, I was really impressed with how smooth and quiet it was. My biggest concern with any of the European developed engines is that they're primarily designed for unleaded gas, which is hard to come by at airports in the US. They will run on 100LL, but I've heard from numerous operators (and the manufacturers manuals) that running leaded fuel shortens maintenance intervals and can cause a variety of issues over time.
Just out of curiosity, who's designing the FWF for the UL installation? Is the mount elongated to move the engine forward for CG?
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Yes, that is an issue. The one I flew behind only flies on Avgas. I currently fly behind an AeroVee VW engine (in my Sonex), and have been using TCP for lead scavenging for 12 years. No issues with lead at the plugs, rings or anywhere else. I do 25 hour oil changes, so if I have to do that, that won't be anything new for me. That will be my tact starting out. I'm hopeful that with all the unleaded aviation fuels being tested, something may be commercially available around me. I've got a couple of years left on my build.

As for the FWF, UL Power makes a 7" engine mount extension to get the CG right. A custom cowl is also available, so I don't have to modify the factory cowl. Both were installed on the RV-7 I flew.
 
SonexGuy said:
Yes, that is an issue. The one I flew behind only flies on Avgas. I currently fly behind an AeroVee VW engine (in my Sonex), and have been using TCP for lead scavenging for 12 years. No issues with lead at the plugs, rings or anywhere else. I do 25 hour oil changes, so if I have to do that, that won't be anything new for me. That will be my tact starting out. I'm hopeful that with all the unleaded aviation fuels being tested, something may be commercially available around me. I've got a couple of years left on my build.

As for the FWF, UL Power makes a 7" engine mount extension to get the CG right. A custom cowl is also available, so I don't have to modify the factory cowl. Both were installed on the RV-7 I flew.
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Seriously considering a 520T for my RV-15 build.
 
I'd love a 7 with the 520T, and one would be pretty cool in my RV-4. Out of curiosity what is the price of one now days?
 
Having owned a smaller 4 cylinder UL 260i for a bit, I wouldn't have one on an RV. It was OK on a microlight type thing... Limiting yourself to an electrically actuated CS prop is a major disadvantage too.
 
IO390 said:
Having owned a smaller 4 cylinder UL 260i for a bit, I wouldn't have one on an RV. It was OK on a microlight type thing... Limiting yourself to an electrically actuated CS prop is a major disadvantage too.
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The 520 is a 320 cu/in 6 cylinder, comparable in size and weight to a lyc IO-320.
 
IO390 said:
All the UL Power engines have a propeller mounting flange which bolts on to the crankshaft. None of them have a hollow crank with oil feed to drive a hydraulic prop.
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I guess I'll never experiment with UL power. Too bad, because a turbo flat six with EFI is exactly what I would want otherwise, but I consider a CS prop mandatory and an electric CS prop a liability.
 
IO390 said:
All the UL Power engines have a propeller mounting flange which bolts on to the crankshaft. None of them have a hollow crank with oil feed to drive a hydraulic prop.
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Correct. The option is an electric constant speed prop, which is the way I'm going (from Airmaster). Oil driven props are also a liability. You just have to determine which one you're comfortable with. With the Airmaster, if the prop control fails, it will simply stay in whatever pitch it's currently at. I don't consider that much of a liability.
 
SonexGuy said:
Correct. The option is an electric constant speed prop, which is the way I'm going (from Airmaster). Oil driven props are also a liability. You just have to determine which one you're comfortable with. With the Airmaster, if the prop control fails, it will simply stay in whatever pitch it's currently at. I don't consider that much of a liability.
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If you get the prop pitch fairly coarse at a high speed cruise, especially cruising at low engine rpm, and it gets stuck in that position, you may not have enough power to climb or go around at lower airspeeds. A hydraulic prop can fail safe to fine pitch. Obviously there are pros and cons to both but that's what would make me nervous.
 
skirting_virga said:
If you get the prop pitch fairly coarse at a high speed cruise, especially cruising at low engine rpm, and it gets stuck in that position, you may not have enough power to climb or go around at lower airspeeds. A hydraulic prop can fail safe to fine pitch. Obviously there are pros and cons to both but that's what would make me nervous.
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I'm curious of the rate of failure for electric prop systems.
 
skirting_virga said:
If you get the prop pitch fairly coarse at a high speed cruise, especially cruising at low engine rpm, and it gets stuck in that position, you may not have enough power to climb or go around at lower airspeeds. A hydraulic prop can fail safe to fine pitch. Obviously there are pros and cons to both but that's what would make me nervous.
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Unless you fly into really short strips, based on my RV-6 experience with a number of props, I expect that you would have plenty of performance to perform a go around even if the prop is pitched for economy cruise and you are full gross. You could also manage that risk by choosing longer runways when you are at full gross.
 
Aerobatic, counterweighted hydraulic propellers failure to full coarse pitch. Those planes seem to have adequate power when stuck at full coarse. I wouldn't worry too much about an electric prop becoming pitch-locked on our airplanes. Maybe a gutless-wonder airplane, but don't install a UL260 in an RV10, and one should be fine.
 
David Z said:
Aerobatic, counterweighted hydraulic propellers failure to full coarse pitch. Those planes seem to have adequate power when stuck at full coarse. I wouldn't worry too much about an electric prop becoming pitch-locked on our airplanes. Maybe a gutless-wonder airplane, but don't install a UL260 in an RV10, and one should be fine.
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That's good to know there's a real-world example. I sort of figured that if you had a coarse prop pitch capable of limiting the engine to 2400rpm at max MP and ~170 kts, it would have almost unusable power if you had to go around from 70kts or less.

I've always been curious about aerobatic props from the perspective of engine out glide safety.
 
skirting_virga said:
I've always been curious about aerobatic props from the perspective of engine out glide safety.
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Probably not much difference. Our plane has best glide ratio (prop fine, from test flights) of 1/6, maybe 1/6.5 when put on coarse (not measured). So more of a "plummet" than a "glide"...
 
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