Eagler's Nest

Engines => 2 smokers => Topic started by: Grant Thomas on June 09, 2024, 10:46:35 AM

Title: Hirth F23-50HP 2 Cylinder motor (Boxer)
Post by: Grant Thomas on June 09, 2024, 10:46:35 AM
So, I've been doing research for the LEXL I want to build, and I think I've found my Engine.  A Hirth F-23 engine.  It produces 50 Hp at only about 80 lbs. with an electric start.  It is a boxer type 2-cylinder 2 stroke engines, similar to a 1/2vw.  ON paper though it seems to be far superior.  Lighter weight, more reliable, and far more powerful, not to different in price.  These are proven on quicksilver ultralights and I'm wondering if anyone has seen one put on a LE or LEXL?  If so, I could really use some input as to whether this would be a good selection for the LEXL I'm going to build.  Ive supplied the USA main dealer for these einges below, thanks- Grant Thomas

http://www.recpower.com/F-23%202%20cycle%2050hp.htm
Title: Re: Hirth F23-50HP 2 Cylinder motor (Boxer)
Post by: Dan_ on June 13, 2024, 06:19:48 AM
I have experience flying with Rotax 2 smokers.  The power to weight ratio of any 2 cycle is undeniably appealing.  They use a lot of gas and oil.  The synthetic oil available now is amazing, and expensive.

Always cover exposed air filters with a plastic bag when you put the plane up for the day, they are a dust magnet and can appear clean but still be clogged.  I had a 503 total power loss on the downwind just after takeoff.  The engine never quit it just bogged when the throttle was opened much beyond idle.  I was able to turn base just after mid field and landed uneventfully.  If this had happened during the initial climb past the end of the runway..?

Never pull the power back abruptly after take off.  Do it in small intervals or they can cold seize.  A friend had this experience in his Mini-Max after a cruise-climb and he had one with this model of Hirth engine, but he has had many ultralights and I can't swear if this plane had a Rotax or the Hirth but the lesson is clear.

The only other forced landing I have had was in a Quicksilver.  I had a prop mostly disintegrate when my helmet visor departed and went through the prop.  It happened off the end of the runway, but too far to make it back.  The prop pieces could have taken the tail off.  Totally my fault.  One of the many lessons here was use the top of the waist high wheat as the runway not the actual ground.  The nose wheel caught in the first few kernels and flipped me...

My opinion is 2 stroke engines are not necessarily less reliable, but they are more fickle.  Be prepared to become an expert.
Title: Re: Hirth F23-50HP 2 Cylinder motor (Boxer)
Post by: Grant Thomas on June 13, 2024, 10:50:22 AM
THANKS!!!! I appreciate the information and advice, I'm glad you made it through your ultralight hiccups.   Everything helps and I appreciate the community!  Have a good day!
Title: Re: Hirth F23-50HP 2 Cylinder motor (Boxer)
Post by: Jrdunn on October 05, 2024, 11:41:00 AM
Grant Thomas , Were you quoted a price?
Title: Re: Hirth F23-50HP 2 Cylinder motor (Boxer)
Post by: Grant Thomas on October 05, 2024, 12:27:17 PM
I was, I'll attach the sheet for you, it was from June just to let you know.  I have decided not to go with this engine to start, rather I plan to go with the Verner 3v radial, because of direct drive and the big reason price.
Title: Re: Hirth F23-50HP 2 Cylinder motor (Boxer)
Post by: Jrdunn on October 05, 2024, 02:07:52 PM
Thank you.  I can see what you mean.  Me, I'm still in the dreaming stage.  Jim
Title: Re: Hirth F23-50HP 2 Cylinder motor (Boxer)
Post by: pappyadkins on October 05, 2024, 08:00:09 PM
Seams Leonard says 2 cycle is probably a no go for vibration or harmonics if I remember right... You may want to ask to be sure...
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