carb icing in Rotax 912 ULS in an RV12

2johns · #1 01-14-2018, 08:53 PM

Has anyone had carb icing in their RV12

gblwy · #2 01-15-2018, 02:34 PM

Not I (in soggy Scotland)

Infidel · #3 01-16-2018, 06:09 AM

I've accrued a couple hundred hours behind 912/912S' and have never encountered icing.

vic syracuse · #4 01-16-2018, 06:45 AM

Over 1300 hours behind 912's in Kitfoxes, RV-12's, and Just Superstols with no carb ice. That includes flight in actual IMC as well.

Vic

Piper J3 · #5 01-16-2018, 10:36 AM

In another thread titled "Air Induction Option" I wrote that the J3-Cub I owned for more than twenty years had an updraft carb on Continental A65-8 engine. You could view the entire carb through the open cowling. I would land on a hot summer day and the carb would be dripping wet (literally) from condensation - cold carb / humid air. Carb ice was always a possibility.

I have 300TT on my RV-12 with zero incidence of carb icing. Nice powerful, smooth running engine...

Art_N412SB · #6 12-04-2019, 08:25 AM

So, the air around the carb filters is hot because it is at the back of the engine. I get that. But, how hot is it? Did Van's put a temp probe near the carb filters during flight testing? I think about these kind of things on wet Pacific Northwest days.

rvbuilder2002 · #7 12-04-2019, 08:58 AM

A lot of testing (including the use of temp sensors) was done during the early development of the RV-12.
This was more for evaluating what benefit in performance there would be if a cold air induction system were used (yes, even that was tested but found to not be worth the added cost and complexity).

This testing (and Van's is locate in the wet Pacific North West), along with the accumulated flight time of 650+ RV-12's flying many thousands of hrs around the world, in widely varied flight conditions, has provided data that indicates carb. icing is not an issue.

RV12JT · #8 12-04-2019, 12:18 PM

During my annual/condition inspection, my mechanic showed me how the Rotax was designed and showed me the fitting adjacent the carbs that hot coolant flows thru. So, no need for carb heat it?s built in.

rvbuilder2002 · #9 12-04-2019, 12:47 PM

Quote:

Originally Posted by RV12JT

During my annual/condition inspection, my mechanic showed me how the Rotax was designed and showed me the fitting adjacent the carbs that hot coolant flows thru. So, no need for carb heat it’s built in.

The standard 912ULS engine delivered by Van's with the RV-12 kit does not have any passages that route hot coolant through/around the carburetors (and I am not aware of any other version of the engine that does either).

There is an aftermarket kit to add this but I am not aware of any RV-12 ever having it installed, though I guess it is possible that yours has.

Tony_T · #10 12-04-2019, 01:07 PM

I believe RV12JT has a Sling aircraft. Sometimes important details are left out.