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Rotax 912

912 vs c-90

Anyone out there know how a Cont. C-90 would compare to the Rotax 912s as far as weight and deminisons. I know the C-90 is old but it is still going pretty strong in a lot of planes my age.

Hal-san
 
Rotax cooling system

Hi,

commonly here in Europe we use system where water and oil is circulated through same system thus they will have same temperature. This significantly speeds up gettin' temps up. This is standard installation in some planes like Dynamic WT-9 (http://www.czechsportplanes.com/).

Laminova2.jpg

So the solution exists to solve issues with Rotax cooling so not using it is IMHO more like user error than system error... ;)
 
Pirkka said:
Hi,

commonly here in Europe we use system where water and oil is circulated through same system thus they will have same temperature. This significantly speeds up gettin' temps up. This is standard installation in some planes like Dynamic WT-9 (http://www.czechsportplanes.com/).

Laminova2.jpg

So the solution exists to solve issues with Rotax cooling so not using it is IMHO more like user error than system error... ;)
Click to expand...

Now that is just silly. Everyone one knows water & oil don't mix. ;)

:eek:

I had heard about those devices. Great idea for getting oil temps up to par prior to take off. Do you use oil thermostats also?
 
Last edited:
Pirkka said:
Hi,

commonly here in Europe we use system where water and oil is circulated through same system thus they will have same temperature.
Click to expand...
Interesting. I've never heard of / seen such a system here in the US. Normally, if it uses anything, there will be a thermostat on oil and, if you're in a really cold climate, coolant. There's also the $0.25 solution of a strip of metal foil HVAC tape over the top 2" of the oil cooler.

TODR
 
hoped it would be about the same

lcnmrv8r said:
the c-90 ends up being (if I remember) about 50 pounds heavier installed weight. Dimensionally the rotax is, I'd say 25% smaller.
Click to expand...

Thanks. Thought it may be close enough to the Rotax to squeeze it into the RV12. Of course if Van does not hurry it may not matter to me as I am now only 4 months shy of being 70. May be too old to tackle the building of an RV 12. I am just not sold on the Rotax 912.

Hal-san
 
Harold,
I think the 12 will be available by spring.
I hope you don't think you are too old to
build it, because I want as much company
in our age group as possible. One of my
arguments for building again are the benefits
in mental and physical health it provides.
Don't laugh, 'she who must be obeyed' has
bought into it.

I'll be 71 years young in March,
Tom
 
Age

I am 72 and don't feel it. I,ve built a RV-6 & RV-9 and plan to build a twelve. When we have a RV Fly-in here in Florida most are over 65 and some are older than me and still building.( Alot of gray and bald heads) Like me alot of us are looking foward to having the twelve kit availible.
Gerry
RV-9, N92GC
Cub, NC88583
 
Hey, you old guys need to keep building. It gives me somthing to look forward to! Keep up the fight. NEVER let them win!

If you rest, you'll rust.
 
Glad to see age not a problem

tomwebster said:
Harold,
I think the 12 will be available by spring.
I hope you don't think you are too old to
build it, because I want as much company
in our age group as possible. One of my
arguments for building again are the benefits
in mental and physical health it provides.
Don't laugh, 'she who must be obeyed' has
bought into it.

I'll be 71 years young in March,
Tom
Click to expand...

Tom,
I guess as long as I am able to walk 18 holes of golf three times a week, I should be able to pop some rivets. I still have to sell it to 'she who must be obeyed'. I did my flight training not too far from your area. About 90 miles if I remember right. That would be in Middletown, O. (Aeronca country).

Hal
 
Age and experience go together (76 this year). I'm flying the dickens out of my RV-6a (weather allowing) and waiting patiently (?) for the RV-12.

jerry t (Elkhart IN)
 
Geico266 said:
Do you use oil thermostats also?
Click to expand...

I'm concentrated more on flying... :rolleyes: I've feeling I've discussed earlier about this and we don't use thermostat. It's one possible unreliable element more. However for sure it would help here too.
 
the_other_dougreeves said:
There's also the $0.25 solution of a strip of metal foil HVAC tape over the top 2" of the oil cooler.
Click to expand...

That tape doesn't help much when you are trying to get initial temps up -- air flow is at totally different level compared when you are flying. We do use that tape as well too. RPM is low and oil doesn't get warm. But as water (coolant) goes through cylinder heads it warms much quicker so if we circulate oil and water through same system, the 'hottest spot' of the engine is also warming oil.

And as I said in previous reply, I've feeling that thermostats aren't used in general with Rotax installations.
 
rotax turbo 914

Does anyone have any thoughts on using a turbo 914 instead of the 912 in the RV-12 ? i SPEND A FAIR mount of my time in the Durango,co area where airport density altitudes are often well above 10,000 ft in the summertime.
 
fdoppelt said:
Does anyone have any thoughts on using a turbo 914 instead of the 912 in the RV-12 ? i SPEND A FAIR mount of my time in the Durango,co area where airport density altitudes are often well above 10,000 ft in the summertime.
Click to expand...

Have you checked the price of one lately?:(
 
rotax turbo 914

westexflyboy said:
Check out the discussion in following thread-

http://www.vansairforce.com/community/showthread.php?p=174408&highlight=RV-12T#post174408

Chase Snodgrass
Presidio, TX
http://flybigbend.com
Click to expand...

thanks for the info on the rotax 914turbo. I currently fly a falco andhave no trouble in the 16 to18,000 ft arena, with oxygen of course. I live in the southern az area and have a home in durango, co area. I'm always at 12,000 plus to make the trips I have to, to salt lake city and durango from tucson. I'm only thinking of the future ( re medical). I presume that the faa will finally bend to change their 10,000 ft rule to something more sensible,i.e. 3000 ft above agl. I really don't feel light sport would be an option for me unless there is a more suitable engine for altitude than the current 912.
 
fdoppelt said:
I presume that the faa will finally bend to change their 10,000 ft rule to something more sensible,i.e. 3000 ft above agl. I really don't feel light sport would be an option for me unless there is a more suitable engine for altitude than the current 912.
Click to expand...
This AGL altitude was discussed during the preliminary meetings on the light-sport rules, and it was decided that they don't want sport pilots flying above 10,000' regardless.
 
Coinneach said:
Mel, what was the rationale behind the 10K ceiling? Need for supplemental oxygen?
Click to expand...
Yes, this was the primary concern. The whole idea of sport pilot is to require minimum training and very low cockpit loads. The original proposal did include an AGL addition, but it was voted down. Is there a possibility that it could be changed? Certainly. But I wouldn't hold my breath.
 
Anywhere in the 1400 - 1600 range works well. If you get it too high the plane will want to float forever. At least that's my experience in the CT. Mines at 1500 which gives a closed throttle 1900 on a 55 knot final.
 
Anything below 1700 seems to vibrate a lot, even with well set up carbs. The gearbox wear increases a LOT below 1800 RPM. There's a great clip in the DVD that ASA and Lockwood put together on the 912 where you can hear the rattle the gearbox makes at low RPM.

TODR
 
Hey Doug - -

I agree with you, but as mentioned, if you set the warm engine idle at 1800 or more, you are seeing 2100 on landing, and you just float for ever. Ok to set for 1500, but run it above that if setting in line, warming up, etc.

John Bender
 
JBPILOT said:
I agree with you, but as mentioned, if you set the warm engine idle at 1800 or more, you are seeing 2100 on landing, and you just float for ever. Ok to set for 1500, but run it above that if setting in line, warming up, etc.

John Bender
Click to expand...

I agree with John.
I have found 1600-1650 RPM to be a good idle stop setting for the RV-12.
Then never idle it there.
The pilot should always keep the engine running smooth during ground ops. This requires keeping it at about 1800 RPM or above (that is why the green arc on the tach starts at 1800RPM). In flight, with the throttle pulled to the idle stops the engine will still be very smooth with relative wind driving the prop. and engine to a higher RPM. This will enable the shortest possible landings and steepest approaches. After slowing to a slow taxi or stopping on the runway, simply advance the throttle slightly to get back up to 1800 RPM.
 
rvbuilder2002 said:
I agree with John.
I have found 1600-1650 RPM to be a good idle stop setting for the RV-12.
Then never idle it there.
Click to expand...
Yep. The only time I'm at fully closed throttle is during power-off approaches and taxi downwind (the CT will easily pick up a LOT of speed otherwise).

As for float, a little slip always does the job. Once you've slipped a sailplane about 30 deg off axis at 15 feet agl on a no-spoiler approach, slips in power become really easy. :)

TODR
 
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