RV15 power plant. UL520T???

[AeroEngineer]

Originally Posted by PilotjohnS

Will Vans go for 390 hp io720 in the -15...?

If Mike Patey buys a -15 kit, I presume he would!

[David Z]

Could anybody afford to feed an IO-720? That's basically 2x angle valve IO-360s, so ~20gph depending on the speed lever setting.

If we are going silly and joking around, give me a R-985! Who wants 390hp when one can have 450 hp and the sweet sounds of a radial. 20 Canadian gallons per hour would get a bit expensive though.

[campipilot]

Is there anybody on here with experience with the UL engines. I’m thinking that UL520T might be a good fit for the RV 15. Any thoughts or experience with their engines here?

[Mike Houston]

Hearing rumours of Rotax releasing a 160HP version of their 4 cylinder engine 915 turbo charged engine (916). So 135HP continuous and 160 HP for 5 mins at take off. The engine will weight about 120 lbs less than IO 390. So you could probably expect same performance or better on RV15 at 8000 ft and above.

Take off probably a bit slower off the ground but probably not a lot given the weight savings

[rv6ejguy]

Originally Posted by Mike Houston

Hearing rumours of Rotax releasing a 160HP version of their 4 cylinder engine 915 turbo charged engine (916). So 135HP continuous and 160 HP for 5 mins at take off. The engine will weight about 120 lbs less than IO 390. So you could probably expect same performance or better on RV15 at 8000 ft and above.

Take off probably a bit slower off the ground but probably not a lot given the weight savings

Not comparable to a 390 until you get to 10,000 feet or so. The takeoff roll would be much longer given 55hp less at SL.

[Remedy]

I’m wondering if there will be enough room for a Continental IO360. 210 hp. 6 cyl smoothness. About same dry weight IO-390.

[Megaglutes]

Originally Posted by campipilot

Is there anybody on here with experience with the UL engines. I’m thinking that UL520T might be a good fit for the RV 15. Any thoughts or experience with their engines here?

there is a guy on YouTube with an RV-7 and a UL 520 engine! idk if there is a way to contact him but he did an excellent job. he had to displace the engine 7.25" forward due to CG and the 60lbs lighter engine lol. im excited! here's his channel.

https://www.youtube.com/@PHMNX

[skiloop]

Originally Posted by Remedy

I’m wondering if there will be enough room for a Continental IO360. 210 hp. 6 cyl smoothness. About same dry weight IO-390.

Fingers crossed.

[Lithosis]

I'm really hoping that UL520T is a supported option from Vans. If it isn't, and I'm going the unsupported route anyways, I might actually look into throwing the 3 Cyl Yamaha on the front with a skytrax gearbox. An RV-15 version of Steve Henry's YeeHaw 8. Anyone with me?

[gmcjetpilot]

Personally I would stay clear of UL Power. I know about the UL520. Not familure with turbo charged version UL520T except for what is on their web page I can say the effective HP or thrust from their engines in not as advertised. It is a complaint of many. They get their claimed HP at 3200 RPM. It is direct drive and that is too much RPM for Prop efficiency. The special prop they use can only do so much. Also it burns as much or more fuel as a Lyc, on HP to Gallon basis.

What is Van's RV-15 engine: "Lycoming IO-390 four-stroke powerplant, driving a 80-inch Hartzell Propeller Trailblazer three-blade, constant-speed propeller. The Lycoming O-360 will be an option." Stick with that, unless you want to make your own engine mount and custom intake, exhaust. deal with a 100 custom design and system installation design and fabrication. More build time for sure.

The UL Power advertised power is optimistic with rated HP by a good bit. I know of an RV7 with UL520 engine. The custom engine mount, CG issues. slower speeds (more like a 160HP) while burning same GPH. Not impressive. In 2019 prices a Lycoming was $10,000 less than UL Power. Now they are about the same. Stick with what Van suggests and has designed the plane for.

Prop on UL is either fixed or a very expensive AIRMASTER electric prop ($15,000) made om Australia. Have a problem good luck. UL power it also made far away in Europe. Give me a Lyc and Hartzell Hydraulic Prop.

Early models of the UL520 had piston and cylinder issues. There is Facebook group for UL Power. There are some pictures of broke internal parts. They sold engines with CAST pistons. They failed. I believe they are using forged pistons now.

If it's ain't Lycoming I ain't going. 3 years ago Lyc prices were $25K to $36K new the UL520 was $38,000 rated at 200HP but really makes 180HP or less. The UL530T I guess is $48,000. Why? More time and Work to build deviating from plans, lower performance and more cost. Why?