Rotec TBI

[carpat]

Hi guys,
Would like to know if some of you are using the Rotec throttle body injector on your Rotax 912S or 914? Any comments from different engine users welcome too.

Pat

[Gravity_Knight]

Bumping this for new info....

I installed the zipper 114hp setup on my 912 uls in my rans s6s. Along with some custom exhaust mods, and the rotax airbox and some other goodies. Performance is good (best of 1200fpm sustained climb at 7500ft altitude (field elevation for me is 6500ft in CO), fuel burn is extremely good (I have 21x8 mains and a 18x6 nose wheel I modified the nose fork for) and at 110mph indicated cruise I see around 3.75gph burn on average (and that is with my 72" 3 blade KOOL scimitar pitched pretty fine (5500 cruise rpm).

But me EGT's are a little strange (I have 4 channels, along with an wideband 02 sensor and a hacman for leaning). Depending on throttle setting, I see the largest swings between front and rear cylinders (both banks). It's obvious the intake manifold doesn't flow exactly the same. I'm going to try leaning the carbs a little to see if I can calm it down with that (like the jabiru guys do) once I can get through the huge snow drifts by my hanger.

Been looking into the Rotex TBI. Very interesting stuff... little info here and there from searching, actually haven't read anything bad. Thought maybe I'd see what experiance you kitfox guys have with it!?

[ken nougaret]

I put one on my o-200 but havent run it yet. I got it because i had read all good things.

[Av8r3400]

It would be interesting to see some type of equal flow downdraft intake manifold for this unit, for use on a 912. A rework of the cowling and coolant surge tank and associated line routing would be required, but it would certainly not be an end of the world type of project.

[TahoeTim]

I ran one on my Zenith 601 with a Jabiru 3300 engine. I never saw the issues others has with getting the cylinder temps to balance. It was a great carb. I think a pair of them on a 912 would be the cats meow.

[SkySteve]

I have 21x8 mains and a 18x6 nose wheel I modified the nose fork

Gravity Knight,
Any chance for a photo of your tires/wheels and nose fork? I'm working on something for my plane.

[Gravity_Knight]

It would be interesting to see some type of equal flow downdraft intake manifold for this unit, for use on a 912. A rework of the cowling and coolant surge tank and associated line routing would be required, but it would certainly not be an end of the world type of project.

definitely agree! I could build it, but I don't have a flow bench or anyway to verify it really flows equally until actually trying it... but I would be interested in this for sure

I ran one on my Zenith 601 with a Jabiru 3300 engine. I never saw the issues others has with getting the cylinder temps to balance. It was a great carb. I think a pair of them on a 912 would be the cats meow.

Nice! thanks for the info!

I put one on my o-200 but havent run it yet. I got it because i had read all good things.

hope it works well! I did a lot of reading on the VANS forum, and the biggest issue that hasn't already been resolved is that some units need the wide open side of the spray bar holes drilled out a little (its like jetting it)....

Gravity Knight,
Any chance for a photo of your tires/wheels and nose fork? I'm working on something for my plane.
Yesterday 04:56 PM

Attaching a couple pictures. The nose fork on the rans is different than the fox, but maybe it will help. I bought the tundra fork but it wasn't tall enough to accommodate the 18" tall version of the 6.00-6 tires (that I can't actually find anywhere for sale... I got 2 of them through a rans builder/friend, but most of these are only 15" tall). I had to build a make shift jig to hold everything, I cut the end off, extended it around an 1 inch or so iirc, I used a mild steel inner pipe, and then a 4130 outer pipe.

[fastj22]

I'm running a Rotec TBI on my Jabiru 3300/Sonex. It really balanced my EGTs and is much more refined than the AeroCarb it replaced.