Rotax versus Camit for a Onex

[gcm52]

Larry in N. Idaho.

Lastly, I can't see a Rotax ever working well in the Sonex airframe. I have no beef with the quality or integrity of the product whatsoever. Rotax has their own quirks and Service Bulletin issues but have the biggest market share for good reason. My comments are based on the gear reduction aspect. The Rotax will turn a big prop slowly. Very efficient for an airplane that has about a 2-1 speed range. Cruises up to about twice the stall speed. My friends RANs S6 cruises about 100MPH.
Contrast that with the Sonex airframe that can easily reach 3-1 speed range and the lower speed, geared prop just won't cut it.
My Waiex with the previous Jabiru would cruise easily !48MPH and decend at about 2,700 rpm from cruising altitude at about 300-400 FPM descent at 160-163 mph in smooth air. If I had a Rotax running at 5,100 RPM in the same scenario, I'd be willing to bet it wouldn't go much over 120 mph straight and level and 130-135 downhill due to the prop holding the plane back.
If your flying a Rans type high wing or a Just Aircraft, or a KitFox, etc, I believe the Rotax is far superior for the above stated reasons. My guess is slow moving airplanes have real issues trying to cool a Jab? Just my guess.

I am not sure why this would be true. There is an Australian plane, the MCR01, stalls at 47kts and has a top speed of 172kts with a Rotax 100hp. That is more than a 3:1.

[Waiex 49]

There are a lot of fast European airplanes using the Rotax. Generally speaking, they have three blade propellers. I believe all the Sonex aircraft that have been powered by Rotax engines use three blade propellers, and they go much faster than you have projected.

[sonex892.]

. Jabiru 3300 183.5lbs, Camit 182.4lbs, Aerovee 185lbs less oil. I'm guessing the turbo would take the aerovee weight up to 200 or more.

Just to clarify, that weight is for the turbo AeroVee. The non-turbo AeroVee is listed at 160 lbs.

Apologies for posting mis information about the weight of the aerovee. I was indeed looking at the Aerovee Turbo page.

There are a lot of fast European airplanes using the Rotax. Generally speaking, they have three blade propellers. I believe all the Sonex aircraft that have been powered by Rotax engines use three blade propellers, and they go much faster than you have projected.

I believe the speeds that could be achievable with a 912 would come down to prop and pitch settings. Adding variable pitch is an easy addition to a 912 and would be something to consider if wanting the best of both worlds. Climb and cruise.

Even though the Camit is relatively unproven. I am sure it will prove itself to be an improvement over the Jab 3300. My 3300 Jabiru has now done almost 200 hrs troublefree. Given the history and operating restrictions imposed on Jabiru engines here in Australia, I would love to trade up to a Camit.
Steve
Sonex 892

[Concorde]

Any news on Jabiru 3310 ?

[lgsievila]

bye

[WaiexN143NM]

Hi Loren,
Keep us posted on your conversion. I was hoping sonex with the new 'B' models would have some new engine choices for the onex as well. At least a mount and cowl. I've seen a couple of ones with jab2200. If I remember correctly the first customer built onex was a yellow one from Florida , had a long nose. I think the small UL 260 and the jab2200 would be good choices.

WaiexN143NM
Michael Radtke

[lgsievila]

=

[WaiexN143NM]

Hi Loren,
Was looking at the completions list for sonex, I see the jab2200 on a onex, first flight jul 5, 2012. Built by Dan Wright, in Spring Hill FL. Email listed lurelocker@aol.com

Maybe this helps for some info.

WaiexN143NM
Michael RADTKE

[lgsievila]

Hi Mike,
I heard that the Onex for sale without engine had a UL that failed completely and it was built by the same guy. That is why he is selling without engine. Was from a pretty good source.
Loren

[WaiexN143NM]

Hi Loren,
I just looked up barnstormers, saw the ad for the onex, same individual, Dan wright, but I think is a different plane. The picture sonex completions is yellow with black stripes. Looks like a bumblebee. Lists a jab 2200 motor. The ad in barnstormers lists as unpainted. You may want to give him a call to chat, his contacts listed in ad. Suspected UL motor failure? I've heard good things about the UL, but do not mount the ecu, firewall engine side. It can't take the heat.

Good luck on your conversion.

WaiexN143NM
Michael Radtke