Who's heard of the Rotax 912 RST turbo engine?

[Guest Rocko]

While puttering around on the net, looking at different plastic fantastic dreams, I came across the web page for the Xenon gyroplane. Now, while not especially interested in the Xenon itself, although it is pretty impressive albiet well outside my price range, one of the engine options available is a Rotax 912 RST. (as well as the 912S and 914)

 

According to their specs, this engine is configured as follows:

 

The 912 RST model uses a smaller 80 HP Rotax 912 engine (smaller than the 100 HP 912S mentioned above). This engine has been fitted with a Mitsubishi Turbo that gives full time turbo boost. At full power this engine develops 122 Horsepower and is excellent for heavier loads or high altitudes.

 

the web page in question is located here...

 

http://www.zenogyro.com.au/models_specs/

 

So, here we have a Rotax 80HP engine, remodeled to be more powerful than the 914 turbo, and weighing about the same?

 

That'd put it as a very interesting competitor for the Jabiru 3300.

 

So, why has noone ever mentioned this before? While I have little to do with Rotax enginesd, owning a Jab 2200 powered aircraft, I'm still curious, and I've never heard of this as an option? Nor is it listed in Bert Flood's page as an option. The only other place mentioning it is the Rotary wing forum for gyroplane users.

 

http://www.rotaryforum.com/forum/showthread.php?t=12499

 

Anyone else know anything about this engine?

 

Cheers,

 

Scotty

 

 

[youngmic]

There are probably 42 reasons why it is not a popular engine.

 

If it were a turbo normalizer that might be worth a second look, but as it stands it sounds more like a pressure cooker with a faulty latch, excitement just waiting to happen.

 

 

[Kitplanes]

Reviving this old thread. This engine has been used by Gyro manufacturers for many years. Not many people know this but it is actually approved in Germany as a CA912ULST engine on the Xenon. On the certificate it states that the take off power is 107Kw at 5200rpm and continues is 96kw at 5000rpm. I think the rpm restriction is because of the noise requirements in Europe. This power seems a bit excessive for this engine for reasons stated below. The Rotax 914 is a 912 UL with the turbo and assosiated electronics as well as ignition module that delivers spark at different intervals between the two units.

 

The RST (we call it the ST (Super Turbo) engine) is as mentioned above the same engine with the major difference that the turbo is mechanically controlled with the vacuum. The biggest disadvantage of this engine is that if you slam the throttle open, especially at sea level, it can be over boosted but this is where pilot training comes in. So in short. When used with the new Rotax casing later than 2006, this engine at 120hp will give you a 2000hr TBO no problem. If you boost it over 120hp then you are in Lion country and on your own. A friend of mine owns a Gyro manufacturing company and he has been using these engines for the last 12 years. He is of the opinion that for every 5hp over 125hp you can loose as much as 500hr's on your TBO.

 

 

[Kitplanes]

Reviving this old thread. This engine has been used by Gyro manufacturers for many years. Not many people know this but it is actually approved in Germany as a CA912ULST engine on the Xenon. On the certificate it states that the take off power is 107Kw at 5200rpm and continues is 96kw at 5000rpm. I think the rpm restriction is because of the noise requirements in Europe. The Rotax 914 is a 912 UL with the turbo and assosiated electronics as well as ignition module that delivers spark at different intervals between the two units.

 

The RST (we call it the ST engine) is as mentioned above the same engine with the major difference that the turbo is mechanically controlled with the vacuum. The biggest disadvantage of this engine is that if you slam the throttle open, especially at sea level, it can be over boosted but this is where pilot training comes in. So in short. When used with the new Rotax casing later than 2006, this engine at 120hp will give you a 2000hr TBO no problem. If you boost it over 120hp then you are in Lion country and on your own. A friend of mine owns a Gyro manufacturing company and he has been using these engines for the last 12 years. They

 

 

[microman]

We have a couple of aircraft at our field with 912 engines that have been modified with big bore kits and turbos to produce around 120hp. They are both fitted to Zenith 701 aircraft and their performance has to be seen to be believed. They can virtually take off without any roll and being fitted with 26 inch tyres of course land very short as well. However both have had issues - on one the crankcase developed a crack - since replaced and has done about 20 hrs since. The other had massive oil leaks which may have been unrelated to the increased power but certainly were as a result of the mods done. So I guess nothing is for nothing.

 

 

[facthunter]

I wouldn't be boosting that engine to those figures. It's not the world's strongest bottom end and the crank is pressed up and 3 main bearings. When it goes everything is expensive. Nev

 

 

[Kitplanes]

I wouldn't be boosting that engine to those figures. It's not the world's strongest bottom end and the crank is pressed up and 3 main bearings. When it goes everything is expensive. Nev

Exactly the reason we only take them to 120hp and not the figures used by Celliers.

 

 

[facthunter]

Boost makes more sustained torque available without peak pressure increase. Lower operating RPM can unload an engine. Extra heat can be dealt with in a liquid cooled engine, Just leaving the drive to cope. Nev

 

 

[Kitplanes]

We have a couple of aircraft at our field with 912 engines that have been modified with big bore kits and turbos to produce around 120hp. They are both fitted to Zenith 701 aircraft and their performance has to be seen to be believed. They can virtually take off without any roll and being fitted with 26 inch tyres of course land very short as well. However both have had issues - on one the crankcase developed a crack - since replaced and has done about 20 hrs since. The other had massive oil leaks which may have been unrelated to the increased power but certainly were as a result of the mods done. So I guess nothing is for nothing.

This is very true and one of the reasons you cannot use a pre 2006 engine case for these mods. It needs to be a new engine or very close to new to be able to sustain the 120hp for 2000hr's. The pilot also has to use common sense and not boost the engine for 5min. Just use the power to get off the ground and then throttle back. That way it will last forever. Our climb rate in the Safari is 1400ft/min @700kg at sea level and with that rate you only need to boost for 30 sec or so to be clear of almost any runway obstacle.