Hummel is flying an Ultracruiser with a Predator

Homebuilt Aircraft & Kit Plane Forum

Help Support Homebuilt Aircraft & Kit Plane Forum:

Niels

Well-Known Member
Joined
Aug 15, 2019
Messages
253
Is said Predator engine a 0.67 litre.4000rpm,22 horsepower and 50 kg engine that can propel a Hummel Ultra with a 200lbs pilot?
 

Bigshu

Well-Known Member
Supporting Member
Joined
Jun 7, 2020
Messages
1,422
Location
KCMO, midwestern USA
Is said Predator engine a 0.67 litre.4000rpm,22 horsepower and 50 kg engine that can propel a Hummel Ultra with a 200lbs pilot?
No, it's modified to increase hp to somewhere between 35 and 42. A stock Predator engine won't work. You can modify the engine easily, if you're handy. You can also do it in stages to keep the cost manageable, but until you reach the finish line, you won't have enough hp. You also remove some parts to get the weight down to the minimum.
 

Vigilant1

Well-Known Member
Supporting Member
Joined
Jan 24, 2011
Messages
8,399
Location
US
No, it's modified to increase hp to somewhere to between 35 and 42. A stock Predator engine won't work. You can modify then engine easily, if you're handy. You can also do it in stages to keep the cost manageable, but until you reach the finish line, you won't have enough hp. You also remove some parts to get the weight down to the minimum.
When somebody puts a calibrated club on that 670cc engine/setup and makes 35-42 HP, then I'll believe it. And then if they fly it at the same fuel burn rate as the test, we'll see how long it goes before the CHTs go to 500 F.
 
Last edited:

Flyguyeddy

Well-Known Member
Supporting Member
Joined
Mar 28, 2020
Messages
181
When somebody puts a calibrated club on that 670cc engine/setup and makes 35-42 HP, then I'll believe it. And then if they fly it at the same fuel burn rate as the test, we'll see how long it goes before the CHTs go to 500 F.
I dont know about the predator, but the briggs seems to be running quite well on the weller rebels out there
 

Vigilant1

Well-Known Member
Supporting Member
Joined
Jan 24, 2011
Messages
8,399
Location
US
I dont know about the predator, but the briggs seems to be running quite well on the weller rebels out there
Yes, and there are some Lucioles flying successfully with a modified Honda 627cc engine as well (and doing it with direct drive). But even Roman Weller only claims 29HP for the engine in his Rebel, turning it at 4400 RPM.
I don't doubt at all that some small airplanes can fly on a V-twin of less than 700cc. But I doubt that any plane is reliably making and using "35-42 hp" from a Predator 670cc engine.

IMO, the folks who make "overly ambitious" claims for these nice little industrial engines do a lot to damage the broader acceptance of the engines. The same thing happens when people over-promise for other good engines (the reputation of the VW Type 1 as an aero engine has suffered a lot from this same thing).
 
Last edited:

Flyguyeddy

Well-Known Member
Supporting Member
Joined
Mar 28, 2020
Messages
181
Yes, and there are some Lucioles flying successfully with a modified Honda 627cc engine as well (and doing it with direct drive). But even Roman Weller only claims 29HP for the engine in his Rebel, turning it at 4400 RPM.
I don't doubt at all that some small airplanes can fly on a V-twin of less than 700cc. But I doubt that any plane is reliably making and using "35-42 hp" from a Predator 670cc engine.

IMO, the folks who make "overly ambitious" claims for these nice little industrial engines do a lot to damage the broader acceptance of the engines. The same thing happens when people over-promise for other good engines (the reputation of the VW Type 1 as an aero engine has suffered a lot from this same thing).
I see what you mean. I think that the comparison is being made to the alleged horsepower of the half vw engine. I may be wrong about that tho.
 

Bigshu

Well-Known Member
Supporting Member
Joined
Jun 7, 2020
Messages
1,422
Location
KCMO, midwestern USA
I see what you mean. I think that the comparison is being made to the alleged horsepower of the half vw engine. I may be wrong about that tho.
Regardless of what the actual sustained hp of the souped up Predator is, the OPs original question is can the 22hp stock version get his Hummel UC airborne. I think that answer is still no.
 
Top