SonexBuilders.net

I really like the OneX design. I don't want to use a VW engine.

I've used a hand propped C-65 in the past, it was reliable as gravity and they're available at similar cost and weight to a VW with an electrical system.

I can't seem to find a C-65 or C-85 powered OneX (or Sonex) on the internet. Has there been a builder that has done this already?

Thanks

PS ... I'm not trying to ignite a debate over the merits of the VW, many of you have had great experiences with this engine. I just don't want to use a VW engine.
I'm trying to locate someone who has already addressed the issues that using a C-65 or C-85 would create.

What is the HP and max RPM of the engine you're mentioning (I'm not familiar)? One of the main issues with typical aircraft engines in a Sonex is the lack of ground clearance to swing a big enough prop at lower max rpms. Most Sonex engines run at 3000+ rpm.

Standard max rpm for a C-85 is 2750 ... race pilots typically operated them at 4000 rpm (with a smaller diameter prop). Steve Wittman who raced C-85s for a couple decades stated there was no reduction in reliability if the C-85 were operated at 3400rpm and below.

So it would be a matter of working with a prop manufacturer to find a balance between what the engine needs and what the airframe will allow ... the kind of issues already addressed by a builder who has installed a small Continental engine.

Do you know of a builder who has installed one?

A Continental C-series engine is way too big and way too heavy to hang on the front of a Onex (or a Sonex for that matter). And there's the prop issue, which is not a small deal. And even without the weight, there's getting it to fit. Those magnetos stick out a LONG way on the back of the engine, and with it being too heavy to begin with, you can't really move it forward to get it to fit. The Onex is not the right plane if you are set on a Continental engine. It was specifically designed around the AeroVee engine, and that's truly what works best.

Sonerai13 you work for and represent Sonex Aircraft.

Sonex want's the profit from selling AeroVees. Sonex says Corvairs won't work either ... except they do.

I've flown behind a VW for 300 hours, and I'm done with them, too much tinkering, not enough flying.

Anyway, if someone knows of a Sonex or OneX builder who has tried to install a small Continental engine please let me know.

Thanks for your help.

Hey Mr. Blue Ridge,

We try to be polite here on this forum, especially to our friends at Sonex. In case you didn't know it Joe Norris is a former DAR and a former big shot at EAA. He leads Sonex's transition flight program. We are fortunate to have him in our community and we cherish his advice.

You can not fit a C 65 or a C 85 on a Onex. Look up the dimensions.

One guy did put a Jabiru 3300 in his Onex and is currently flying.

Jake

Jake and Joe, thanks for contributing. Joe I apologize for attributing a profit motive to Sonex's position.

I met an owner who installed a C-85 on a Sonerai. Everyone told him it could not be done, including the designer John Monnett.

He pressed on and the conversion turned out great.

I said in the original post I was not looking to debate VW versus. I was merely trying to identify if someone had tried to install a Continental engine.

Joe is well known and is probably right.

All I've asked is ... does someone know if a OneX builder has tried.

BlueRidge wrote:I won't apologize for that. I don't think it's impolite to ask.

It's not impolite to ask; but when you get a reply and immediately snark at the person to imply that they're just after profit, THAT is impolite.

You got real engineering reasons back as to why it's not a good idea, and rather than try to refute them with facts or figures, you proceed to question the person's motives and use an entirely different aircraft as your "evidence"!

If you look around this board you'll find discussion aplenty about Corvair engines and Rotaxes and Vikings - the people on this board are happy to discuss alternative engines. But only if those discussions are grounded in facts and not snide remarks or "because I wanna" wishful thinking.

If you want to contend that Conti engines can fit on one of these aircraft despite being told that the weight and dimensions don't work, then feel free to pull out engine specs and the Sonex/Waiex/Onex specs and show how it can work/fit after all. That will be taken seriously by the folks here, and your efforts will be respected.

--Noel

I was not claiming it would work. I was trying to identify someone who had tried.

Ok, small Continental won't work on the OneX. Thanks for your help.

BlueRidge wrote: Sonerai13 you work for and represent Sonex Aircraft.

True. But before working at Sonex I worked at EAA for 10 years, giving technical support to all EAA members. I have given this exact same advice to EAA members while working there, and will give it again in the future. I want all builders to be successful once they decide to build. Thus, I try to give sound advice. It is up to the person to whom I give the advice whether they choose to accept it or not.

BlueRidge wrote:Sonex want's the profit from selling AeroVees. Sonex says Corvairs won't work either ... except they do.

You are welcome to put any engine on the airframe that you want. And there are many choices that will work. But a C-series Continental just won't. There are better choices, whether you choose AeroVee or not. The C-series Continental is a poor choice for the Sonex airframe.