Sport Pilot Talk

Bender · Joined: 15 Aug 2007 Posts: 8 Location: Lorton, VA USA

I see that the CZAW Sport Cruiser has the option of the Rotax or the Jabiru engine. Does anyone know the pros and cons of these engines?

Thanks,

Jeff

CharlieTango · Posted: Wed Sep 12, 2007 8:29 am Post subject:

the jabiru is harder to keep cool

Jeff Tipton · Joined: 26 Nov 2006 Posts: 98 Location: Dickson, TN

Jabiru requires Avgas 100LL and the Rotax can use Premium auto fuel.

Rotax takes less time to complete 100 hour inspections.

Paul Hamilton · Joined: 21 May 2007 Posts: 340 Location: Reno/Tahoe Nevada

Check out the video trailer on the 912 half way down the page to provide some background on the 912

http://www.ap-store.com/asaf2f912.html

:?

pequeajim · Joined: 17 Sep 2006 Posts: 40 Location: New Holland, PA

CharlieTango wrote: the jabiru is harder to keep cool

Actually the Jabiru is no harder to keep cool than a Lycoming, or any other air cooled engine. It also can use auto fuel just like the Rotax and is much easier to service due to less parts.

bitten192 · Joined: 21 Dec 2009 Posts: 50 Location: RICHLAND WA USA

Jabiru needs a head overhaul @ 1000hr and TBO 2000hr. 912ULS just upped their TBO to 2000hr.

drseti · Joined: 28 Nov 2009 Posts: 1193 Location: Lock Haven PA

bitten192 wrote: 912ULS just upped their TBO to 2000hr.

True, but read the Rotax service bulletin carefully. The very newest 912s (by s/n) are automatically upgraded to 2000 hr TBO. The slightly older ones (including mine; the SB lists which s/n's) require that one screw and one spring be changed. (The parts list for under $40). The oldest ones require replacement of some crankcase parts, so I don't know how practical (or expensive) the mod will be for those.

In any case, as I read it, to comply with the SB, one must overhaul the gearbox at 1000 hrs.

rfane · Joined: 26 Apr 2006 Posts: 214 Location: Sunnyvale, CA

drseti wrote: In any case, as I read it, to comply with the SB, one must overhaul the gearbox at 1000 hrs.

This is a change in our favor as well. The gearbox overhaul had been due at 800 hours previously.

rsteele · Joined: 12 Feb 2007 Posts: 259

There is a huge philosophical difference in these two engines. Don't know if it matters to you or not..

The Jab is a 6 cyl. and runs smooth as silk and is relatively quiet. It's direct drive and air cooled so it's as dirt simple as a Conti or Lync. It's a 125 HP so its about 30 more than the Rotax, and this is a LOT.

The Rotax is a 4 cyl and there is no way anybody could call it smooth, even though cruise RPM is around 5000 to 5200. It's water cooled, which adds complexity, but avoids issues like shock cooling that you can have in air cooled engines.

Historically the Jab has had cooling issues, but from what i've been reading, the newer installation have that sorted out. The Rotax has had issues with the gear box, but again, these have been addressed and newer installations seem to be rock solid.

I fly behind a 912ULS but have only been a passenger behind a Jab. The Rotax has an excellent service record and there are starting to be shops that can work on them. This might be more of issue with a Jab. The deciding factor for you may be the availability of a mechanic.

Personally, I love the smooth running and quiet Jab, but if I were putting my money down, don't know what I'd do.

Ron

drseti · Joined: 28 Nov 2009 Posts: 1193 Location: Lock Haven PA

rsteele wrote: I fly behind a 912ULS but have only been a passenger behind a Jab.

I've flown them both, Ron, and I generally agree with your comments about smoothness, simplicity, and philosophy. However, I chose to purchase a Rotax-powered S-LSA for one reason not previously mentioned: ubiquity. The Rotax powers about 80% of the S-LSA fleet. This means parts and mechanics are more abundantly available than is the case for the Jabiru.

FLA-CFI · Joined: 27 Oct 2008 Posts: 45

rsteele wrote:
The Rotax is a 4 cyl and there is no way anybody could call it smooth, even though cruise RPM is around 5000 to 5200.

Have you mechanic properly balance the carbs...you'd be surprised how smooth you can get that engine to run when each side is producing the same amount of power.

rfane · Joined: 26 Apr 2006 Posts: 214 Location: Sunnyvale, CA

FLA-CFI wrote: rsteele wrote:
The Rotax is a 4 cyl and there is no way anybody could call it smooth, even though cruise RPM is around 5000 to 5200.

Have you mechanic properly balance the carbs...you'd be surprised how smooth you can get that engine to run when each side is producing the same amount of power.

Very true.