Traveling with a twin engine 2 stroke airplane?

[blane.c]

For an aircraft designed for 170 ci, personally I doubt it will perform well with 35.44 ci. HP is just one number not the whole story.

Specifications (Rotax 582)[edit]
General characteristics

• Type: two-cylinder, two-stroke, rotary valve, oil-in-fuel or oil-injected lubrication, dual carburetors, electronic dual ignition
• Bore: 76 mm (2.99 in)
• Stroke: 64 mm (2.52 in)
• Displacement: 580.7 cm³ (35.44 cu in)
• Dry weight: 50 kg (110 lb) with electric starter, carburetors, fuel pump, air filters and reduction gear

Components

• Fuel type: premium unleaded: RON 90 octane or higher leaded or unleaded or AVGAS 100 LL
• Oil system: oil-in-fuel (pre-mix) or oil injection
• Cooling system: liquid cooled

Performance

• Power output: 48 kW (64.4 hp) at 6,500 RPM
• Compression ratio: 11.5 (theoretical) - 5.75 effective
• Power-to-weight ratio: 0.59 hp/lb (1.07 kg/kW)

Specifications (O-170-3 or A-65-8)[edit]
Data from Continental Aircraft Engine Operator's Manual[2]

General characteristics

• Type: 4-cylinder air-cooled horizontally opposed aircraft piston engine
• Bore: 3.875 in (98 mm)
• Stroke: 3.625 in (92 mm)
• Displacement: 171 in³ (2.8 L)
• Length: 31 in (787 mm)
• Width: 31.5 in (800 mm)
• Height: 29 5/16 in (745 mm)
• Dry weight: 170 lb (77 kg)

Components

• Valvetrain: One intake and one exhaust valve per cylinder, pushrod-actuated.
• Fuel system: Updraft carburetor
• Fuel type: 80/87 octane avgas
• Oil system: Wet sump
• Cooling system: Air-cooled

Performance

• Power output: 65 hp (48 kW) at 2,300 rpm
• Specific power: 0.38 hp/in³ (17.1 kW/L)
• Compression ratio: 6.3:1
• Fuel consumption: 4.4 US gal/hr
• Oil consumption: maximum desirable 0.37 US quarts/hr
• Power-to-weight ratio: 0.38 hp/lb (0.62 kW/kg)

 

[ragflyer]

Got 67 power-loss accidents with Rotax 582s. The Rotax 582 does come out a bit better than the overall two-stroke results; about 32% of 582-powered aircraft accidents are engine related. Here's the breakdown as to causes:

Cause​	Count​
Undetermined​	28​
Engine Internal​	19​
Fuel - Engine​	3​
Fuel - System​	5​
Ignition​	2​
Reduction Drive​	4​
Oil Delivery​	0​
Carb Mechanical​	3​
Cooling​	3​

Three out of the four "Reduction Drive" cases were for belt reduction drives, not the Rotax gearbox. The fourth was due to corrosion in the "Power Takeoff Bearing" which may actually be on the engine itself.

"Fuel - Engine" is problems with the fuel system inside the engine compartment, while Fuel - Systems is for fuel delivery problems within the airframe. I do lump those in with the engine-related cases.

Ron Wanttaja

thanks Ron....much appreciated. The 582 seem better but overall cluster with other two strokes.

 

[BBerson]

Running an engine direct drive may be a usable solution but it is not the same as derating. In fact it can actually increase stress on the engine if the BMEP is higher at that RPM.

Derating is normally meant as operating at less than rated power.
That could be either less rpm or less mean effective pressure. Do you have any reference of an aircraft engine damaged by operating at half power with high mean effective pressure?

 

[EzyBuildWing]

Austrian paramotor engine-manufacturer "EOS" is now building 4-stroke 250 cc singles....
26HP, 14Kg, 75Kg static-thrust.

Maybe TWO of these 4-strokes could be mounted as pushers in the EMG airframe? (lower vid)>

EOS QUATTRO 4-STROKE Engine - Coming Soon! – WASP PARAMOTORS

 

[trimtab]

Haven't heard any sort of aeronautical analysis of this system, but suspect the overlap area has some horrid effects.

Contrarotating props can enjoy significant system efficiencies. Resonances can be reduced by using different blade counts.

 

[EzyBuildWing]

Blue Yonder EZ Flyer was a twin 582 pusher......Looked great, but seems no one wanted it.......check it out here:

Blue Yonder Twin Engine EZ Flyer - Wikipedia

en.wikipedia.org

 

[BBerson]

Two engines doesn't qualify for LSA in USA. Apparently, the FAA didn't think twins were overall a value to safety.

 

[EzyBuildWing]

Kolb flyer....with twin German SOLO 13 HP direct-drive 2-strokes....... would obviously be better/safer as a tri-motor.

For flying over desert like this, 3 obviously better than 1 or 2.....

 

[Bille Floyd]

...

A twin does not increase reliability, it doubles the likelihood of an engine failure. The safety benefit of a twin comes from the ability to keep flying and ideally still climb on one engine. Without folding or feathering props, that can be a real challenge.

What If :
The two engines, both interface with the same PSRU, and both engines
had a clutch, to disengage at any moment needed ? Now you have one
prop, that doesn't need to feather , (it might need to be in-flight pitch adjustable though).

Bille

 

[akwrencher]

Yes, would need inflight adjusted or you wouldn't be able to use the power from one engine. Also, easier said than done. The basic setup would not be a big feat of engineering, but making it reliable could be......

 

[EzyBuildWing]

Twin 28 HP independent Hirths driving contra-rotating props via individual belt-reductions, propelling this airframe would be REALLY neat!

 

[Speedboat100]

Isn't there a noise issue with 2-strokes ???

 

[akwrencher]

That's a cool little plane. Reminds me of one of Fritz W's renderings, the one tube fuselage.

 

[EzyBuildWing]

They've put a direct-drive electric motor on this very simple and inexpensive Lithuanian glider !
Take a look:

Russian Efly 1A Begins Flight Tests - Sustainable Skies

Aleksey Sychev completed two airplanes and at least two motors of three planned – he has built his EFly 1A, motors, controllers, and battery packs.

sustainableskies.org

 

[Sockmonkey]

Since engines and aircraft are created by humans, any failure is thus human-related. Humans designed them, humans built components, humans assemble them, and humans operate them. On that basis, 100% of all accidents, not just engine failures, are "human related." Guess I should just delete my databases and relax.

This is being needlessly pedantic. The point is that unlike freak weather, you can eliminate engine failure as a likely danger by just doing proper maintenance.

 

[Wanttaja]

This is being needlessly pedantic. The point is that unlike freak weather, you can eliminate engine failure as a likely danger by just doing proper maintenance.

"Eliminate" seems needlessly optimistic. Parts break, and routine maintenance doesn't always prevent it. I once had a bolt shear in half on my tailwheel spring bracket. Under a microscope, there was an obvious rusty line on the broken face showing where corrosion had advanced. No way it would be detected under normal maintenance. But perhaps "proper" maintenance would have included complete disassembly of the aircraft.

Four stroke engines have dedicated systems to put oil where it is needed. That's one reason they're heavier and more complex than two-strokes. But they do seem to have fewer seizures.

Ron Wanttaja

 

[Sockmonkey]

"Eliminate" seems needlessly optimistic. Parts break, and routine maintenance doesn't always prevent it. I once had a bolt shear in half on my tailwheel spring bracket. Under a microscope, there was an obvious rusty line on the broken face showing where corrosion had advanced. No way it would be detected under normal maintenance. But perhaps "proper" maintenance would have included complete disassembly of the aircraft.

Four stroke engines have dedicated systems to put oil where it is needed. That's one reason they're heavier and more complex than two-strokes. But they do seem to have fewer seizures.

Ron Wanttaja

I did specify that it made such failures unlikely, not impossible.

Anyhow, are there non-diesel opposed-piston two-strokes?

 

[n3puppy]

Anyhow, are there non-diesel opposed-piston two-strokes?

Many through the years - right now the 50hp Hirth F23 is the most common in aviation use

 

[Sockmonkey]

Many through the years - right now the 50hp Hirth F23 is the most common in aviation use
View attachment 105571

No, I mean configured like the Junkers Jumo. Twin cranks.

 

[Werner]

here a tri motor.

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