SonexBuilders.net

I'm at a point where I need to (quickly) finalize my decision on an engine. It's between the Jab 3300 and the UL Power 350iS.

I'm impressed by the UL Power but my biggest concern is the fact that it is fairly intolerant of 100LL. A steady diet leads to valve fouling/deposits and early cylinder work, per reports. I would prefer not to have to transport auto-gas to the airport. I'm also a little concerned as there just isn't as much experience with the engine here in the US, though there are quite a few flying in Europe. I'm okay with the electrically-dependent part aspect of UL Power and the fact that that it is another $5k. The extra 10 hp is a nice, too.

The 3300 is a known quantity and the Gen 4 seems to have gotten most things right. I'd still probably ditch the Bing and go with the Aeroinjector. I had thought that the Jab installation might require less custom cowl work than the UL Power but some recent posts and talking to a few -B builders using the 3300 have led me to believe that I'll still need to do a fair amount of modification--especially for the oil cooler.

I'd appreciate any input. I would really like to finalize an order by next week.

BTW, going to cross-post this on the FB Sonex builder's page. Apologies in advance.

Hi N43WX,
i would suggest the jab3300.
simple totally aircooled . pwr to weight.
parts avbl thru arion the jab dealer.
one side you could put electronic ignition. leave one side orig and self contained coil spark.
the UL is nice. but needs an electrical source. so does that mean dual alternators, batteries , and voltage regulators?
regarding 100LL. use tcp or similiar.
id leave the bing on and fuel pump. want a slide tbi? id go with a rotec.
just my 2 cents. and worth every penny.
good luck with your decisions!

WaiexN143NM
Michael

Read what SPA (manufacture the Panther kit) has to offer for Corvair. If you look at the lead times for jabiru you might be encouraged by a ready to ship engine kit. They supply engine mounts, baffle kits, etc.

If you are willing to invest the effort to build your own engine you may be well ahead in the long run with the knowlege gained.

They may build it for you. Worth a look.

Best of luck whichever way you go.

Gordon

If I had my time over I would have/ should have just went with the Aerovee Turbo. I bought a used Rotax 912ULS and it easily added 2 years to my build and I'm still not totally satisfied with where I put everything. The factory supplied turbo engine would have been much easier and also would have produced more power at altitude than almost all other choices.

Murray Parr wrote:If I had my time over I would have/ should have just went with the Aerovee Turbo. I bought a used Rotax 912ULS and it easily added 2 years to my build and I'm still not totally satisfied with where I put everything. The factory supplied turbo engine would have been much easier and also would have produced more power at altitude than almost all other choices.

Cant comment either way on your observations, however as a 12 year Rotax 912 ULS driver I can vouch for their reputation for reliability, smooth operation (dynamic balance the prop & vacuum balance the carburettors) and economical operation (easy 13 L (unleaded)/hr @ 100 knots). Most 912's will easily make 2000 hrs TBO (if serviced correctly & as per "the book") and go on to operating "on condition" well into the high 2000 hrs. As for performance at altitude - in Australia VFR operations are limited to 10,000ft so the benefits of turbocharging can not really be used. The 912 ULS will carry you effortlessly to 10,000. Expensive to purchase but "cheap as chips" to operate.