Geiger Engine, Aviation Grade Rotary Wankel!

[Flynic3]

Good Evening,

I have been a long time fan of Rotary power and Daily Drive a RX-8. I love their engines for numerous reasons however they do have a few drawbacks with the Design. I won’t get into all of them here but the only aviation motor I have seen that addresses these design issues is the Geiger Motor. This is a relatively new engine and design, and they only recently went into serial production. That being said this is a huge step for Aviation grade Rotary power as most designs never even made it to production. This is not an autoconversion from a 13B based engine. This motor was designed from the ground up to be an aviation motor. The specs are listed as follows... A single Rotor design will produce roughly 50hp and the dual Rotor version will produce 100hp @7500rpm, so of course there is a Reduction Drive. The Wet weight of this engine is said to be 132lbs , so it should be lighter than the Rotax when installed. What is also interesting about this engine is that is has a pretty impressive torque curve. Most Rotary engines do not produce a lot of torque which is needed for an aircraft! They even have a redundant design for helicopters with two complete 100hp engines driving one PSRU, and the total weight of that unit is said to be 325lbs with 200hp. This is the only Rotary I have seen that has addressed the issue of Rotor Cooling with internal pressurized oil jackets in the rotors. This Rotary engine also uses modern ECU control and is said to have a fuel burn of 4.5-5.3 Gallons an hour. The oil usages is also extremely low as it does not need to inject oil into the combustion chamber to keep the Rotor cool. Now here is the clincher my friends... currently the price listed for the Geiger A2-74 engine is $12,800 US! This is the only engine I have seen recently that could possibly give Rotax a run for their money! You can not beat the price per performance or even the weight of this engine anywhere in the marketplace! The production of these engines was said to have begun in April 2017 with 100 engines. The Company Geiger Motors GmBH is based in Germany and I have recently sent them an enquiry. As I stated this is the first Rotary engine that I have seen for aviation that looks promising!

Further Engine information... sorry had to use google translate as the website is in German.

OTHER KEY FIGURES TECHNICAL SPECIFICATIONS
Power 74 kW / 7500 min-1,
Torque 85 Nm / 7500 min-1
MAX RPM 7500 min-1
Fuel Min RON 95
oil 5W30
Generator power 300 (600) W
Voltage 14.2 volts
MASS (in KG) engine 31
transmission
8 Intake silencer with intake manifold
1,8 Fuel pump, pressure regulator,
filter 0.7
Dry sump wet 3.2 l 3.8
Electronics Engine Management 1.9
Alternator 3.2
Starter generator with electrical 12 V, 28 V 3.1

Two-disc - four-stroke Wankelsaugmotor with dry sump lubrication. Sequential high-performance ignition system Electronic engine management with lambda probe Redundant intake manifold injection Integrated starter generator Integrated reduction gearbox Oil-cooled rotor with oil-water exchanger in the cooling circuit for stable temperatures under permanent full load Gas seal system designed for high wear resistance Lowest friction due to rolling bearing of eccentric shaft and rotor Low friction oil seal system.

I am extremely impressed with these specs and can’t wait to hear more from the company about these engines. From what I read they are currently testing the engine in a Flight Designs CT and has spent a large amount of time on the test bed. I would Love to hear your thoughts on this engine! I hope this information helps my friend and if you have any questions please feel free to let me know!

Best Regards,

Nicholas Dawson

[Sonerai13]

Nicholas,

How many of these engines are actually flying? How many hours have they accumulated? Does the company have a US representative, or do you have to deal directly with Germany? How long as the company been around?

In short, do you want to be a true experimenter, and possibly be doing the factory's endurance testing at your expense? Or do you what a proven, reliable, easy-to-get-service-and-support-for engine?

Food for thought.

[fastj22]

I've always been fascinated by rotary engines. I hope this doesn't stall out like the D-Motor did.

[Bryan Cotton]

Years ago I designed flight controls for, and flew a UAV helicopter for Sikorsky. It had a UAV engines single cylinder rotary which weighed 50 lbs, turned 7000 rpm, and made 52 HP with electronic fuel injection. I have never seen a machine more efficient at turning fuel into noise. We went about 20 hours between rebuilds.

That thing in my avatar is the UAV with the wankel.

[Flynic3]

Sonari13,

These engines are just now entering long term flight testing in a Flight Designs CT type aircraft. I understand where you are coming from completely and don’t see these as a viable option currently. It will take them some time to figure things out and get some extended flight testing in. I am just a huge rotary fan and was extremely excited about the design changes made with this engine. I really hope these engines will make it to production however time has proven that this will not be the case. I think they would be better off going with a 3 rotor version that would compete against the 915is with less weight and complexity. I am just personally passionate about having alternatives to expensive market dominating products like the Rotax. I will always root for the underdog and love it when David takes it to a Goliath. Currently these engines do not have a US representative but I would assume they will be deciding these things once the engine makes it to production. I greatly appreciate your post and the food for thought...I agree with you on everything you are saying.

FastJ22:

From what I understand, The main reason the D-motor stalled was not the engine itself but the man that was the original distributor in North America, Doc Bailey. This certainly hurt the name of the parent company as well which has slowed its growth in Europe. That being said there are easily 40-50 aircraft flying with the LF26 engine and all report superior performance to the Jabiru 2200. I have read about aircraft that have over 500 hour since 2013 without any issues. The parent company in Belgium also upgraded early adopters engines for free from the 2.5L to 2.7L after the design change. I feel this engine was given an unfair bad wrap early on due to Doc Bailey and not the merits of the engine. Anything I have ever read has stated the LF26 engine was far superior to the Jabiru 2200 and offers a modern FADEC engine for the cost of the Jabiru. If you are comparing apples to apples which is the Jabiru 2200 and not the 912UL, it is a great engine. I do feel it will offer solid direct drive performance for 2000 hours or more... I am extremely happy to hear that Fisher Flying Products will now be involved with the D-motor and will soon be taking orders for these engines. Sorry to get off topic about the D-motor but wanted to respond as I feel the D-motor will soon be an excellent option.

Bryan Cotton,

That is a pretty interesting UAV project and I would have loved to be involved in something like that. I can imagine with a lightweight engine such as what would be needed for this UAV, you couldn’t put in additional systems to make the engine more robust than a 20 hour overhaul. I think it put out some impressive numbers for what it was though...

Thanks again for everyone’s response to this thread regarding the Geiger engine and I look forward to seeing this engine start production!

Best Regards,

Nicholas Dawson