Best Overall Motorglider available today?

While the Mi engine is better, the E engine is certainly adequate for high altitude operation. I did not adjust the carburetor between sea level and high altitude, it would climb to 13,000 ft. well and begin to run a bit rough between there and 14,000 ft. I have calculated the climb rate for the first 1000 ft on all of my flights out of Truckee (typical density altitude at takeoff is 8800 - 9200 ft.). With the E engine it was around 430 ft/min average, with the Mi engine it has been about 550 ft/min. It out climbs a Pawnee towplane towing a similar glider. My E engine had the original Technoflug prop, however comparing Technoflug and AS props, the climb rate is similar (acceleration is better with the AS). Climb rate at sea level is over 800 ft/min.

On Friday, October 2, 2020 at 8:47:35 AM UTC-7, waremark wrote:
Yes to the difference between the 26E engine and the Mi engine. I had a 26E and have flown a 31. If you operate in the flatlands the engine upgrade is not a reason to change, at low elevations the 26 has good take-off and climb performance (better than the more powerful and injected Arcus M which I fly now, but not as good as the DG 808). If you might need to cross high mountains the injected version would be much more suitable (there is no in-flight mixture adjustment on the carburetor 26E version) and of course the extra power is appropriate for the heavier 31.

The Schleicher gliders have used fine pitched propellers for best take-off performance since a few years after the 26 came out - the quoted ground roll reduced from 300m to 200m (from memory) when Schleicher changed the prop from the original Technoflug prop to their own prop. If you want to fly level under power for your self-retrieve the Arcus cruises faster than the 26, I presume as a result of a coarser prop.

On Friday, October 2, 2020 at 12:46:57 PM UTC-4, jfitch wrote:
While the Mi engine is better, the E engine is certainly adequate

Thanks Jfitch for showing us your beautiful 26mi at the convention.
Can you remind us why you decided to do the conversion from original engine?

Thanks,
Best Regards, Dave

I flew an ASH26e for 2 seasons and now have a V3M which matches its advertised climb rate of 630fpm with its 62hp fuel injected Solo engine taking off from 360ft msl. The 26e with the carb engine got around 500pm so I surprised me to hear the the 26Mi, with a lower power engine than my V3M, will manage 800fpm from sea level. 800fpm seems an extraordinary increase.

The 26e is a lovely glider and the engine is, of course, much quieter smoother than 2 cylinder 2-strokes but the rotary engine is too vulnerable to catastrophic internal damage if anything goes wrong with the marginal at the best of times rotor air cooling and the internal oil misting. The saying about self launching glider IC engines is - "with the Solo you will probably get lots of relatively small problems, with the rotary you'll get fewer problems but when you do it could be a very big one". There are certainly a few replaced rotaries in gliders that I know of and that is a big bill. I had the fan belt fall off and the engine rotor air rapidly overheat but got away with it.

Is there a rec.aviation.mortorglider for all these boys that don't fly
sailplanes???

Paul T wrote on 10/3/2020 12:56 AM:
Is there a rec.aviation.mortorglider for all these boys that don't fly
sailplanes???

You are asking about what we call "touring motorgliders". The best place to start
is the Touring Motorglider Association forums:

https://www.motorgliders.org

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to email me)
- "A Guide to Self-Launching Sailplane Operation"
https://sites.google.com/site/motorg...ad-the-guide-1

Touring motorgliders seem to be simply airplanes with longer wings.

On 10/3/2020 7:07 AM, Eric Greenwell wrote:
Paul T wrote on 10/3/2020 12:56 AM:
Is there a rec.aviation.mortorglider for all these boys that don't fly
sailplanes???

You are asking about what we call "touring motorgliders". The best
place to start is the Touring Motorglider Association forums:

https://www.motorgliders.org


--
Dan, 5J

Dave, there was no good reason to do it. The E engine was running fine, had 45 hours on it, and it still running today in another glider. A number of 26E owners over the years have expressed interest in this conversion. We had the engine and were curious about AS claim that this was not a trivial endeavor. Also, I was going to need to replace the Technoflug prop at some point, and the Mi engine already had that prop. It turned into a bit more work than we (Rex and I) had imagined - perhaps AS was right - but the result is a nice upgrade. The alternative way to get an Mi engine is to spend the $1/4M dollar bill for a 31.

On Friday, October 2, 2020 at 5:41:57 PM UTC-7, wrote:
On Friday, October 2, 2020 at 12:46:57 PM UTC-4, jfitch wrote:
While the Mi engine is better, the E engine is certainly adequate
Thanks Jfitch for showing us your beautiful 26mi at the convention.
Can you remind us why you decided to do the conversion from original engine?

Thanks,
Best Regards, Dave

I have written an application that will analyze an IGC file (or many IGC files at once) to calculate time to climb and climb rate. I dumped 20 years worth of my IGC files into it. The climb rate at sea level with the E engine was a bit over 600 if memory serves, and a bit over 800 with the Mi (I do not fly often at sea level). About the same percentage increase at high altitude. If you want to send me some IGC files, I can throw them into the same app.

There have been a couple of instances of fan belt failures on the rotary, a few of us have installed warning indicators for this possibility.

On Saturday, October 3, 2020 at 12:30:55 AM UTC-7, wrote:
I flew an ASH26e for 2 seasons and now have a V3M which matches its advertised climb rate of 630fpm with its 62hp fuel injected Solo engine taking off from 360ft msl. The 26e with the carb engine got around 500pm so I surprised me to hear the the 26Mi, with a lower power engine than my V3M, will manage 800fpm from sea level. 800fpm seems an extraordinary increase.

The 26e is a lovely glider and the engine is, of course, much quieter smoother than 2 cylinder 2-strokes but the rotary engine is too vulnerable to catastrophic internal damage if anything goes wrong with the marginal at the best of times rotor air cooling and the internal oil misting. The saying about self launching glider IC engines is - "with the Solo you will probably get lots of relatively small problems, with the rotary you'll get fewer problems but when you do it could be a very big one". There are certainly a few replaced rotaries in gliders that I know of and that is a big bill. I had the fan belt fall off and the engine rotor air rapidly overheat but got away with it.

On Saturday, October 3, 2020 at 9:00:01 AM UTC-7, jfitch wrote:
Dave, there was no good reason to do it. The E engine was running fine, had 45 hours on it, and it still running today in another glider. A number of 26E owners over the years have expressed interest in this conversion. We had the engine and were curious about AS claim that this was not a trivial endeavor. Also, I was going to need to replace the Technoflug prop at some point, and the Mi engine already had that prop. It turned into a bit more work than we (Rex and I) had imagined - perhaps AS was right - but the result is a nice upgrade. The alternative way to get an Mi engine is to spend the $1/4M dollar bill for a 31.

On Friday, October 2, 2020 at 5:41:57 PM UTC-7, wrote:
On Friday, October 2, 2020 at 12:46:57 PM UTC-4, jfitch wrote:
While the Mi engine is better, the E engine is certainly adequate
Thanks Jfitch for showing us your beautiful 26mi at the convention.
Can you remind us why you decided to do the conversion from original engine?

Thanks,
Best Regards, Dave

I think if you factored in the cost of the engine and the cost of the labor you would be better off selling your 26e and buying a new 31Mi. You definitely can't get your money back when you sell your converted 26Mi (which really doesn't exist as it is not an AS model).

Tom

On 10/3/20 7:07 AM, Eric Greenwell wrote:
Paul T wrote on 10/3/2020 12:56 AM:
Is there a rec.aviation.mortorglider for all these boys that don't fly
sailplanes???

You are asking about what we call "touring motorgliders". The best place
to start is the Touring Motorglider Association forums:

https://www.motorgliders.org


I believe he was saying that motorgliders aren't really sailplanes and
would like discussions on such to move elsewhere.

Maybe if he doesn't want to read about motorgliders, he could avoid
clicking on threads mentioning motorgliders?