David and Phil give excellent differences. Here is what I tell my clients:
912S is a reasonable price=2C easy to maintain and easy to service.
It is shaky on start and stop so cracks in the exhaust should be watched cl
osely.
Takeoff is not spectacular=2C but ROC is about 500 FPM. TO Roll is 600-700
feet and initial climb is 800 ish with a constant speed prop.
Being normally aspirated=2C the Bing carbs don't lean well above 3500 MSL.
Normal cruise at 5500 MSL yields about 125-130 KTAS at 5.5GPH.
If you plan flight ops below 10K (5500-7500) it is adequate and can yield 2
5-28 NM/GAL
Runs on 90 octane auto fuel without a hitch.
It gives the most bang for the buck for the Rotax series.
Whereas:
The 914 is nearly twice the price.
Troubleshooting is more time consuming and many of us have studied the syst
ems but easy diagnosis is still time consuming.
Pressurized carbs require careful assembly and attention to leaks.
New TCU units can be electronically monitored and analyzed with DOS 8 compu
ter emulators ONLY.
Wastegates normally require lube (although AV gas seems to keep mine lubed)
Requires high octane in hot climates=2C at least 92-93. (I use 100LL)
However:
When combined with a constant speed propeller (more cost)=2C it is a terrif
ic performance altering addition to the Europa.
Takeoff roll is 550-600 feet at 45 KIAS fully loaded. (Ground static thrust
of 500 pounds.) You scarcely have time to check the engine instruments bef
ore you are at takeoff speed. Initial ROC 1500.
In tests=2C my lowly TRIGEAR climbs at max continuous power at an average o
f 700 FPM to 10=2C000 MSL at 90 KIAS fully loaded and some. Most efficient
cruise MPG seems to be 7500-10=2C000 MSL. I flight plan 1.5 GAL and 18 NM
to get to altitude.
It exceeds 140 knots easily at 1000 MSL at max continuous power.
Cruising at 9.5-10.5K=2C I make 140 KTAS at 5.5 all day. Slow down a bit a
nd I can easily get 28-30 NM/GAL.
Higher cruise altitude does not increase range significantly unless equippe
d with a long range tank and lightly built.
When you have to get over the weather quickly as I do=2C the 914 does it be
tter=2C and more reliable than any other engine out there.
The airplane is 20=2C000 compromises flying in close formation=2C the choic
es are yours.
Best Regards=2C
Bud Yerly
Sent from my Verizon Wireless 4G LTE DROID
On Aug 10=2C 2015 6:58 AM=2C flyingphil2 <flyingphil627-europastuff@yahoo.c
o.uk> wrote:
@yahoo.co.uk>
Hi=2C
This is not a Europa related question as such but there are a fair few Euro
pa owners with a Rotax 914-UL.
Does anyone with a 914 have anything really good or bad to say about the en
gine? Are the running / maintenance costs greatly different to a 912-ULS?
Does it use mogas or avgas just as well? Are there any horror stories rel
ated to it or is it just as good as the 912 but with an extra boost when yo
u need it?
Thanks=2C
Phil
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