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View Full Version : jabiru 3300 or 912



kmul
09-14-2008, 07:16 PM
time to start thinking about which engine for kfss. have 3300 sitting in shop but would get 912 if was much better choice. hot in arkansas and wondering if cooling the 3300 would be an issue. and reports arent overwhelming about performance with 3300. any one running a 3300 and what prop and prop dia are you using. dont see why i cant run a 70 inch prop on the 3300. what is the prop dia that the 912 guys are running on the series 7 and the ss. is the jab performance less because it is being run with shorter props. keith

RandyL
09-14-2008, 07:34 PM
I'm sure others will comment on the relative differences of the engines, but you might also consider installation time and hassle. Kitfox Aircraft offers a turn key firewall forward kit for the Rotax, not so for the Jabiru so you'll need to engineer a few things for yourself. This can be VERY time consuming.

kmul
09-15-2008, 06:21 PM
well i am not exactly enamoured with the idea of spending another 20k. hopefully they will get cheaper when the govt stops treating the dollar like toilet paper.(like that will ever happen) so i have been giving my jab another look. at least i paid alot less for it as i got it a long time ago. i know they can run a 70 in prop ok and if performance can be as good as the 912 i might run it. wondering if anemic performance reports in kitfoxes are with those short props. its 40 lbs heavier but it slightly better lb/hp ratio might make up for that with the right prop. going to talk to someone locally running one in a zodiac 601 to find out about cooling it in the summer. keith

kmul
10-25-2008, 05:04 AM
jab 3300 tbo 2000 hrs according to zodiac website. i thought i remembered it used to be 2000 hrs with top end at 1000 hrs. but that was awhile ago and its possible it was extended after the engine had more time in the field. the one in the zodiac i looked at has been flown in temps around 90 and did ok. there were some cooling mods like a larger lip on the trailing edge of the lower cowling, and a small lip on the top of the pilot side cooling air intake to scoop more air off the propwash. no problems with ground cooling at taxi rpms as i was worried about. have committed to this engine and ordered a fwf kit for it. will put a 70 in prop on it.

DesertFox4
10-28-2008, 09:42 PM
I've been watching Jabiru's progress or lack of progress since the late 90's. Most of us in my area that fly the Rotax do so because of reliability, greater choice of props. that will work with the Rotax and of course the huge number of them in service that are performing well above expectations. Support is of great importance too when spending the kind of dollars it takes to purchase a Rotax and Jabiru engine. I'll keep rooting for Jabiru, Rotec and others as we need more viable choices for our airframes and competition is good for everyone. Right now though Rotax has to be outselling Jabiru at least 10 to 1. The Rotax 912 series has served me better than I ever could have expected and it would take a phenomenal engine to get me to consider anything else on my Kitfox. In the meantime I'll keep flying trouble free and watching for what's coming over the horizon.

lbushrod
04-07-2009, 11:02 AM
I mounted my Jab 2200 on my Model II Kitfox replacing the original 582. I also researched engines and read all the AD's I could find. Bottom line, being an older pilot I just could not resist the direct drive, the sound of the opposed engine and the incredibly fine workmanship of the Jabiru.

Jab provided the engine mount, propeller and spinner. Installation was straight forward, the only difficulty was in maintaining my round cowl.
The Jab fits 4 inches forward of the Rotax necessitating the addition of 4 inches to the forward cowling.

The weight of the 582 plus liquids wound up being somewhat more than the entire Jab installation (about three pounds) with no change in W/B. I figure I lost a few pounds and gained 24 hp.

I have close to 400 hours on the Jab with only 1 issue. A small piece of grit became embedded in the #2 intake valve readilly visible on a leak down test which I perform every 50 hours. I removed the head in about ten minutes and had the valve seat buffed. Back together in ten minutes and no problems since.

I can easily pass VNE at straight and level flight, climb at about 1200 FPM @ 70 mph. Normal cruise @75% power is about 90 true with an average fuel burn of 2.8 to 3gph of 100LL avgas. I can burn mogas but choose not to.

I could not be more pleased with my engine although I have read some reports toward engine cooling. I installed a small transmission cooler on the plane only because I was flying a good deal in hot weather at the time. A long climb would heat up but if I stair-steped the climb it was pretty warm but okay. Since adding the cooler I also had to add an oil thermostat (180 f) to get the temps up enough for vaporization.

My Jab purrs like a kitten, has plenty of power, great economy and a nice satisfying sound that I love. I don't mess with it or tweak it or try to modify it. There are 4 Jabs in my flying group and 3-912's. Both are great engines.

Randy asked if I would post some pictures of my engine change out. Since I learned how to post now I will add them to my albums.

You seem to be a great group. Hope to fly with you somedays.

Pete

Av8r3400
04-07-2009, 05:04 PM
How is your short field performance with the Jab and what prop are you running?


Thanks.

lbushrod
04-07-2009, 06:10 PM
Running a Tennessee 62x36 right now, a friend is borrowing my other one.

I generally do not pull flaps on takeoff but I can get off in less than 150 feet with this prop, a little better with the Sensenich. Just a guess because I have never measured. But with a little wind it jumps right off and climbs well.

Pete

Av8r3400
04-07-2009, 10:42 PM
So much for needing a 6' prop for short field performance, huh?

Jab sure does make a nice looking little motor, too. Best of luck with it.

lbushrod
04-08-2009, 10:53 AM
My friend in a Model 3 ordered the same Tennessee prop that I used but what they sent performed much differently. He could not get his takeoff rpm up past 2700 however he passed VNE at 2800 cruise setting.

He returned the prop and they trimmed it apparently because it had the same numbers. This time he could get 3250 on climb but a much slower cruise speed. Now he has to carry 100/200 more rpm to cruise with my plane.

His plane will get off the ground much faster than mine. When I soloed it I was surprised on how quickly it would get off and climb rate was 150 fpm better than mine.

My point is that you can prop for short takeoff or climb or cruise. LSA prohibits in flight adjustable props so for me the Sensenich which is a 64x36 is a better overall prop on the Jab if I really wanted to do a lot of short field work. I can get in and out of a short - soft strip in the desert (500') with either prop.

From my experience the planes with very short cabability cannot cruise with me.

Pete

catz631
04-11-2009, 05:59 AM
For the "what it is worth" dept,a while back I talked to one of the guys at Just Aircraft at an airshow up in the mountains of NC. They had a Jab 3300 installed in their Highlander for testing and had just flown in. I asked how it was working out . He said it was a good strong engine but it did have a tendency to overheat when it was warm out so they were "step climbing" it to keep the temps down. But he also mentioned that they were working on the baffling to try to control that.
You might give Troy a call at Just aircraft to see how it is working out. I think overall they are pleased with that engine.
Dick Maddux
Fox 4
912UL
Pensacola,Fl

lbushrod
04-11-2009, 08:22 AM
I mentioned that I had no cooling issues with my 2200 but had to be careful on a really hot day. Installation of an oil cooler stopped that but most builders do not put enough underpressure opening on their cowls.

I enlarged my lower cowl area way more than I thought I needed and faired it so as not to create a vacuum. After that and the cooler, absolutely no problem, in fact, I had to install a thermostat to keep the engine up to temp on a cool day.

I am helping a friend build a Lightning in Marana, AZ. It uses a 3300. Greg Hobbs, the distributor indicates that there are NO cooling problems on his planes.

Considering the dust you would have to spend on a 912, I think I would go with the Jab.

Pete