Why not Rotax

[jjbardell]

As I continue my search for my perfect Sonex, I have come across a few in other countries that use a Rotax 912is Sport or 914 Turbo.
Why isn't that a popular engine in the Sonex? Just curious as there isn't a lot on Sir Google about this blend of motor/airframe but seems to be a logical fit imop.

[SNX1508]

I can only speak for myself of course, but I did not choose the 912 or 914 due to cost (could buy another airplane kit for the cost of an engine?) and neither are supported by Sonex.

Terry

[garyb]

I am putting a half life 912s in my Sonex,my first choice was an Aerovee but I picked up the Rotax for a good price, just started making the engine mount.

[rizzz]

I can only speak for myself of course, but I did not choose the 912 or 914 due to cost (could buy another airplane kit for the cost of an engine?) and neither are supported by Sonex.

Terry

Same here, cost.

[sonex892]

I can only speak for myself of course, but I did not choose the 912 or 914 due to cost (could buy another airplane kit for the cost of an engine?) and neither are supported by Sonex.

Terry

Same here, cost.

Had the current Jabiru problems surfaced before I bought my 3300 early 2010 I would have more than likely bought and used a 912s Rotax. At the time the decision was made on cost. The Jabiru was 2/3 the price of the Rotax.

I would not be too concerned with not having the factory support.

Steve
Sonex 892

[MichaelFarley56]

I believe the Rotax engine, while successfully grafted onto the Sonex airframe by a few builders, was never a recommended engine based on both cost and complexity. Most Rotax engines are both air and liquid cooled which means you'll need radiators, water pumps, coolant, etc. This adds weight, cost, complexity, etc.

As others have said, it's also an expensive option.

[Concorde]

How much does a Rotax weigh including the radiator and pump and coolant ?

[rizzz]

How much does a Rotax weigh including the radiator and pump and coolant ?

Installed weight is 140 lbs for the 912ULS, 166lbs for the 914UL.
Weight is not an issue with Rotax, even with radiators, cooling liquid etc.
I don't personally buy the complexity argument as being a risk either. These engines have proven their reliability, probably beyond the sonex approved engine options.
Cost however....
Well, you can build a Sonex including AeroVee engine for that price.

[Concorde]

Thanks for the info Michael .

[jjbardell]

Great info!