SonexBuilders.net

Hi, my name is Ignacio and with my friend Sergio we are planning to build a Sonex-B. There is a little problem, we are from Argentina and here basically we can't import anything from other countries. In theory yes we can, but must pay half of the price in taxes and we got a little problems with dolars.
I'm aeronautic mechanical and Sergio it's an avionic mechanical, so we can build by ourself.
The bigest problem it's the engine, our best posibility it the Rotax 912, but the import problems makes it imposible to bought brand new. We are not going to buy the plans until we got solved the engine than we are going to use.
So I ask, can we use an modified car engine in the sonax ? I know than the bigest limitation is 200 lbs max weight on the front, but I want to ask you if you know of anyone who has already made this modification.
I'm reading you answers! Tnks and grettings

Welcome to the forum! Many Sonex aircraft flying behind some sort of VW car engine, mine included. The Corvair engine has also been flown and seems like a good fit. I have no idea what is available in Argentina. Good luck!

Bryan Cotton wrote:Welcome to the forum! Many Sonex aircraft flying behind some sort of VW car engine, mine included. The Corvair engine has also been flown and seems like a good fit. I have no idea what is available in Argentina. Good luck!

Good to know!
but, in a quick search on wikipedia, it says that the Chevrolet Turbo-Air 6 engine weights 366 lb, so ¿how do you manage the balance problem? ¿do you got any post about how to do the modifications?
Thanks!

Members here post a 220+ lb firewall forward weight with their corvair installations. More info on the corvair here:
https://flycorvair.net/

ArgentinianNoob wrote:
in a quick search on wikipedia, it says that the Chevrolet Turbo-Air 6 engine weights 366 lb, so ¿how do you manage the balance problem? ¿do you got any post about how to do the modifications?
Thanks!

At 366 pounds you don't manage it, you eliminate it from consideration.

Also you mention 'buying plans'. You do know that the Sonex-B models are available in kit form only? Only the original Sonex A model can be built from plans.

There are several car engines being used successfully in homebuilt aircraft. The Viking engine is a Honda with gearbox and the Aeromomentum is a Suzuki engine with gearbox. The problem with adapting a car engine yourself is the gearbox. The propeller imparts some nasty vibrations on the gearbox and companies like Viking and Aeromomentum have gone to considerable trouble trying to isolate the gearbox from those vibrations. It appears to be easy to end up with a system that looks over-designed but in the real world falls apart in a matter of hours. The advantage of the VW engine is that is low revving so can be used without a gearbox. The disadvantage is that power is limited.

Peter

Why don´t you get in contact with Bruno Ceriotti of Santa Fe, Argentina. Ask him how he got around this engine issue. He quite recently had many postings on this and other forums: getting a Waiex A in the air with a R912. I believe the plane originally was built with a VW-1 aeroderivative.