912IS install course letter for attendees CPS

[Sonoma Flight Center]

Attached is a letter from California Power System Rotax training center in S.California. This letter was written by Kevin Kane as an outline of the 912is features for attendees. Kevin is a wealth of information on Rotax engines and he is one of the instructors. Kevin told me that approx. 80% of the 912IS engine has been redesigned, he has updated this from the 60% he quotes in the letter.

I asked him recently why the new engine takes a lot more strength to turn the propeller compared ULS engine. He said the generator has super strong permanent magnets called rare earth magnets.

Here's a Wikipedia explanation;

Rare-earth magnets are strong permanent magnets made from alloys of rare earth elements. Developed in the 1970s and 80s, rare-earth magnets are the strongest type of permanent magnets made, producing significantly stronger magnetic fields than other types such as ferrite or alnico magnets. The magnetic field typically produced by rare-earth magnets can be in excess of 1.4 teslas, whereas ferrite or ceramic magnets typically exhibit fields of 0.5 to 1 tesla.

 

Anyway the CPS 912is install letter is an interesting read that I wanted to share with the group.

Thanks to Kevin Kane. Note; Kevin will be attending the Arlington Washington Fly-in July 11-13th. I will be there too with a 2012 CTLS.

Happy flying!

Ron

CPSAttends912iSTraining.pdf

[Jim]

I'm disappointed that only one EMS works with the engine. Cutting a loyal vendor like Dynon out of the loop is a mistake.

[paul m]

I'm disappointed that only one EMS works with the engine. Cutting a loyal vendor like Dynon out of the loop is a mistake.

 

Is Dynon a Rotax loyal vendor or FD?

 

[Jim]

Dynon products have always had support for Rotax. I don't know all the facts, but it would appear that Dynon was not the EMS vendor that got the inside track on interfacing to the new engine.

[Sonoma Flight Center]

I'm disappointed that only one EMS works with the engine. Cutting a loyal vendor like Dynon out of the loop is a mistake.

Don't be disappointed. Dynon uses the EMS 221 to monitor the SI engine in the CTLSI. The letter from Kevin at CPS was written months ago. Ron

[Ed Cesnalis]

...I asked him recently why the new engine takes a lot more strength to turn the propeller compared ULS engine. He said the generator has super strong permanent magnets called rare earth magnets...

 

How much cruise power is lost to this extra resistance 'takes a lot more strength to turn the propeller compared ULS engine'?

[Sonoma Flight Center]

That's a question for a Rotax expert. My guess is that no cruise power is lost, because when the engine is running the generator is running also. The resistance comes when the engine is off and the magnets are together.

 

 

[Tom Baker]

That's a question for a Rotax expert. My guess is that no cruise power is lost, because when the engine is running the generator is running also. The resistance comes when the engine is off and the magnets are together.

 

You better hope the magnets are not together, otherwise you will have a real bad day. The magnets would have the same force when the engine is running. When producing electrical power you will always have a reduction in engine power. The amount will be a little greater that the elecrical power being used due to eficiency losses.

[GlennM]

"Although I am relatively new to light sport aircraft and piston powered aircraft for that matter."

 

You need a better expert. LOL

[Sonoma Flight Center]

Tough crowd out there. Hope you found the article somewhat useful. LOL

[CT4ME]

very interesting article... 'so much to learn when it comes to to the iS...

tim

[Ed Cesnalis]

Tough crowd out there. Hope you found the article somewhat useful. LOL

 

We have reason to be. I did enjoy the article but I have issues with Kevin and would agree with Glenn, Kevin's expert opinion is subject to change when he needs to deny liability. So I agree an expert should have experience in LSA or at least piston powered aircraft.

 

Even your replies to me have been colored in favor of sales pitch. First you replied that the extra resistance was likely due to extra compression which would imply more power. Next you posited that the extra resistance would not effect power available for cruise. We have seen how some people run with such sales pitches and suddenly the 912iS has more power when the fact is the extra weight and resistance mean less.

 

Thanks for posting it is interesting. I found this interesting: "The engine produces 100HP at take off and more than a few people have asked “why is there only 100HP”... The answer is simple, for LSA 100HP is enough and this engine will burn 20% less fuel than the 912ULS..."

 

All LSA and LSA missions are not created equal, many exceed 100hp some by a large margin.

[Sonoma Flight Center]

I'm glad you liked the article.

[Doug G.]

I am a little surprised they were not using rare earth magnets before they provide more power with less weight.

[CT4ME]

I suspect it has taken some time to work out the bugs... rare earth magnets are extremely brittle, cracking or shattering with little effort. They are also subject to corrosion.

Tim

[Doug G.]

Sure, but wind turbines and hybrid/electric vehicles have been using them for a decade or two. It is certainly not new technology. I would have thought those issues would have been worked out long ago.

[Kevin-Cal Power Sys]

I'm disappointed that only one EMS works with the engine. Cutting a loyal vendor like Dynon out of the loop is a mistake.

 

Jim,

 

At the time I wrote that article, the Michael Stock EMU was the only one EMU available. Since then Dynon and TL Electronics have already produced engine managment units for the 912iS, and Garmin is currently working on one.

 

The 912iS EMU requres a CAN bus to read the data from the engine computer. Apparantly this type of system took some extra development from avionics manufacturers.

 

Kevin