SonexBuilders.net

Hey All,

Well, I got a ride in a 3300 powered Waiex yesterday. What I learned was that you guys are a bunch of dishonest sandbaggers! That thing was WAY better and MUCH faster than you all let on. I'm not sure if the owner wants his name mentioned here, since he might get beat up for letting out your secrets. At one point we were flying down the beach (actually, I was flying and assessing the plane) and the plane was doing 180 mph at 3000 rpm at 2000 feet in level flight,,,, with NO wheel pants. I don't think my RV8A will do 180 with no pants. Now, I don't know if everyone's getting these numbers (and not telling) or if his plane is particularly clean. It was a very good build. The gentleman who owns the the plane has helped a couple of guys transition into their RV's and he excercises their planes when they're up north (snow birds). He also makes plenty of money (compared to me anyway), and still bought, and prefers flying the Waiex. Now for the downsides, yes it is a little snug, I'd definitely have to screen future riders, and doesn't have a lot of baggage space (maybe she can pack smaller), and it's a little louder than my plane at speed.

Why am I looking at sonex's? I have an "A" model RV (nosewheel) on a not-so-good grass strip. Plus the "boss" doesn't admire the back of my head (even though I'm sure it's beautiful, especially the part with hair). I was originally looking at RV6's only, but decided to expand my options. I've always liked the Sonex and decided to get a ride. Now that I've weighed eveything out the planes are running dead even in desirability.

Rv wins - speed (slightly), baggage, cockpit size, less noise, better aileron feel.

Sonex wins - cost to maintain (a lot less) lands slower (by 20 mph, I saw it) burns less fuel, better elevator feel.

That's my take, Lance

Lance.

We probably are a bunch of sandbaggers............but, I'll give you some real world figures I've acquired over time.
My Waiex averages about 138 mph take off to touchdown. That's on a typical 1-2hr ride. Now, I don't run at 3,000 rpm because of the fuel and noise level. My normal low altitude cruise is at 2650 on cold days and 2750 on hot days. The faster cruise means more cooling even at the increased RPM. High altitude cruise (7,500-9,500') I typically will run 2800-2850 and still get my 5.6 GPH fuel burn.
Even though I go faster at altitude it takes fuel to get there so its a mixed bag. I've done many trips at 8,500" or higher and the average speed still seems to come in at that 138 mark when its all done. My Waiex is definitely slower than my friends because I always run without the gear leg fairings. I find them a pain in the butt when taking the cowl off. As a consequence, I run without them. Probably costs me 4 to 6 MPH. Up high I GPS speed consistently 151-154 MPH.
I wish I could compare operating costs long term with my 3300 Jab compared to a O-360 Lycoming? I'll bet the maintanace costs are less on the Lyc? My reason for saying is; no one I know gets the top end time on a Jabiru that most guys get on a Lycoming.

Aha, didn't think about top ends. I agree that the lyc's seem to go the distance that way. The only other engines I've dealt with are the small continentals, they seem to need more attention. What does a top overhaul cost on the jab?

I have 530 hours on my old solid lifter 3300, and am finishing a mini-top end. Honed the cylinders, new rings, lapped the valves, replaced some orings, etc. The engine didn't really need it, but I was going to replace some leaky cylinder base orings, and got a case of the "while I'm in there" and wanted to do a few mods. I think most engines if cooled properly can make it to 1000 hours, even if that means lapping the valves once or twice before you get there. My compression was still good, and I fully expect it to go over 1000 hours before I need to open it up again, fingers crossed.

I would be hesitant to buy one of the earlier hydraulic engines. Lots of potential headaches. The new ones seem decent, but if I were buying new I'd go for a Camit. It's an exact replacement for the Jabiru, but has been refined and beefed up, and all the major problems have been addressed. The Jabiru has had many changes to fix engineering problems, then this creates new problems, and they change it again. Maybe they got it right this time, but the jury is still out.

Another benefit of the Sonex/Waiex is the fuel savings as you have noted. If you calculate the difference in fuel burn by the number of hours you fly a year, that could add up. Hull insurance on a cheaper plane might save you money too.

In the interest of trying to "appear" objective, I do think the RV's are beautiful planes, and I like the idea of more passenger space, although most of my flying is by myself. I have a center stick, so I sit in the middle and it is very spacious. I also think the certified engines are more reliable, and require less care. Better for those that aren't very mechanically inclined, and just want to turn the key on and go.

Either way you're a winner, both planes are great, and if you have the ability and the means to fly, that is what matters. Lucky us!

Almost forgot to gloat......... last year when it was cool out I ran full bore (with wheel pants) and squeaked up to 180. Very stable. Lowered the nose a little and hit 200, still stable. I'm no Chuck Yeager, so I gingerly backed off the throttle, and flew home with a grin on my face. I heard of a Sonex owner who accidentally went over 250, so the story goes, without flutter, and lived to tell about it.

My results with a Sonex TD with 3300 are very close to Larry's when at same RPM, but when going from point A to B and not just flying about, I tend to run 2850 RPM at 5.8 -5.9 GPH and go a bit faster. Over 2,850, with Bing carb, GPH start increasing dramatically.

The fun factor increases with the square of the HP.

David A.

Lance,

I'm guessing that by the time one does a "complete" top end overhaul you could easily get into the $5,000-6,000 range if you have it professionally done? When you add up the cost of pistons and rings sets, conrod bearings, bolts, intake and exhaust valves, seats reconditioned, intake joiner tubes, seals and gaskets, cylinders honed, just to touch on the highlights.........you can feel the Visa card just sliding out of your wallet.
I am currently waiting on the completion of two heads being reconditioned with new valves, new joiner tubes and intake gaskets. At this stage I'm not doing anything with the cylinder bores or pistons. Strictly head work, which hopefully gets me another year or two down the road till I'm forced to do either a sincere top overhaul or buy a new engine.
I have one of the supposedly best of the breed being a last of the run of the solid lifter engines. Problem is the thicker finned heads are no longer available in the event something should become unserviceable. Add to this the 3/8" throughbolts and cases that need reamed for the larger through-bolts. Flywheel upgrade to starfish, on and on. This history and development and modification of the Jabiru engine series would make excellent fictional reading if not for the seriousness of the impact on owners wallets. Not whining, just sayin. Its all fun, right?

Larry
Waiex 121YX, 440 hrs.

Hey Larry,

Holy cow! That's a lot of money alright. I only paid $8500 for a 300hr O-320. What are you trying to do, talk me out of it? :) Ok then, what about the corvair? I know it's heavier, but everyone who has one love it. It is a LOT cheaper than the Jab and the performance seems to be equal or better. I won't be happy with the 4 banger, like Scotty say "We need more power!" Actually, I've worked on corvairs and really like the engine. I'm also not too worried about the weight. I've got a 975 LB RV8A, and it's not stripped either. Some folks on the forum came mighty close to calling me a liar, and said there was no way (or is that weigh, sorry, can't resist a bad pun) but, I had it weighed by an A&P on certified scales... So I know tricks when it come to controlling weight. Thanks for any input.

Flame suit on, standing by, Lance

Lance,

I know several guys with Corvairs and quit honestly, they love them.
Seems the William Wynn guy has them thoroughly sorted out. Sonex won't bless them because they don't support the install from an engineering standpoint so there is no help there. You wouldn't be breaking new ground because its been done several times before. There is always the firewall forward weight issue.
Additionally, there is a growing number of Viking(Honda Fit) engine installs and they seem to be holding up well. Without starting and old war, my biggest lump in the throat with the Viking is the gentleman behind the engine. I know of some people that never got what they paid for in his previous engine life. Hard for me to get over that and move on. Not an uncommon story in the homebuilt aircraft world. Lots of great ideas that are underfunded, under tested, underperforming and eventually bankrupt.
My whole reason for going Jabiru in the first place was to get a factory bought engine with the most HP I could get at the time. This was in 2010 when I purchased my new Jabiru 3300 in a crate from a guy that gave up on his Highlander. I thought it was a bargain at $10,500. At the time, a new hydraulic 3300 was selling for about $18,500 from Sonex.
Unfortunately for many, but not all, Jabiru's have ended up being less of a store bought, install it and fly it and more of an install it, tinker with it, try and cool it, try and follow the service bulletins, and generally chase it in circles trying to keep up on it's numerous operational issues. None of the issues have effected me personally but, I also keep on top of it and never let things stray. I love the smooth power and sound. I'm not so thrilled about its general lack of toughness compared to a Lycoming or similar. This leads us full circle back to the underfunded, under tested, experimental nature of you run what you bought.
There flat out is no substitute for testing and refinement, combined with proven engineering. About any contraption can be made to work for "awhile". The trick is to make something pretty much any responsible Joe can install and make work without major hickups of one kind or another. Time always proves out whether a company got it right. For us Jabiru owners I think we've got a ways to go yet. I'm 75% happy and 25% wishing the guys designing this thing had put a bit more effort into making it tougher and less prone to operator error as the company would say.
One thing there is no denying and that is, the Jabiru really gives the Sonex or Waiex some real spark. I couldn't do with anything less now.

Larry

I agree with everything Larry has said even going down the Viking route briefly only to abandon it after finding out about his history.

I really like the power I get out of my Jabiru 3300. But it isn't a set and forget deal. It takes just as much tweaking, care and feeding as any other experimental engine solution.
I have a Corvair core sitting in my garage now. I paid $220 for it. It will take $10k to bring it to the point I'd fly behind it. There are other exciting options coming on the market such as the 130HP D-motor, the UL-power, the Gemini diesel. And the Aerovee and Revmaster Turbo. None of these were available to me when I had to decide what to hang on my Waiex.

fastj22 wrote:I agree with everything Larry has said even going down the Viking route briefly only to abandon it after finding out about his history.

I really like the power I get out of my Jabiru 3300. But it isn't a set and forget deal. It takes just as much tweaking, care and feeding as any other experimental engine solution.
I have a Corvair core sitting in my garage now. I paid $220 for it. It will take $10k to bring it to the point I'd fly behind it. There are other exciting options coming on the market such as the 130HP D-motor, the UL-power, the Gemini diesel. And the Aerovee and Revmaster Turbo. None of these were available to me when I had to decide what to hang on my Waiex.

Don't overlook the CAMit engine option. Everything Ian Bent has improved has been with intent to improve reliability and longevity and it is a drop in replacement for a Jabiru, only a few pounds heavier, mostly due to much improved cylinders. Also an option to purchase a just a new core if you have worn out Jabiru, and transfer expensive bits like carb and starter.

David A.