In my (rusty) memory, a certified Rotax has no documented major overhaul, and I even heard rumours that official German distributors will not sell separate crankshafts, not even for the non-certified. With a non-certified engine, all is up to the owner/operator, though, and the crankshafts are available, at least at one famous address in France (where my engine will go in case of serious issues).
Peter wrote:
How many of the 14k go into go-karts, etc?
According to the video Rotax makes 200k engines per year. Most of those, 93% to be exact, goes to skidoos, ATVs etc. 7% goes to aircraft. 7% of 200k is 14k.
Rotax vs Lycoming is a factor 9.33
“From 1989 through June 5, 2014, we have sold 50,000 four-stroke engines of the 912 and 914 model designation,” noted Christian Mundigler, key account manager of Rotax Aircraft Engine Sales. “On the two-stroke engine side we sold altogether more than 120,000 units up to now.” Link
The average four stroke (Rotax 912 and 914) production over 25 years is 2000 engines/year.
Jan_Olieslagers wrote:
In my (rusty) memory, a certified Rotax has no documented major overhaul, and I even heard rumours that official German distributors will not sell separate crankshafts, not even for the non-certified. With a non-certified engine, all is up to the owner/operator, though, and the crankshafts are available, at least at one famous address in France (where my engine will go in case of serious issues).
Uncertified Rotax engines are rebuild and customized all the time. For the engine in our WT9 to tug gliders, we upgraded to “big bore”. Aftermarket cylinders and pistons giving about 120 hp (1700 cc). It’s just a matter of time before the first Rotax “clones” start to appear, just like the Lycoming clones.
LeSving wrote:
It’s just a matter of time before the first Rotax “clones” start to appear, just like the Lycoming clones.
Longcin in China builds clones of Rotax motorcycle engines for BMW. I’m sure Rotax was very happy with where that might go in the future 
Peter wrote:
The roller tappets solve this
What makes you so sure? Do we really already know this, given that roller tappets exist for only about 7 years? Even the flat top tappets easily make 7 years…
Re roller tappets, and FWIW, other engine types with the same 21st century flat tappet issues have successfully solved the problem with roller tappets. One example is 8V Guzzi motorcycle engines, introduced in 2009, big tappet breakup problems, nothing since the 2013 roller tappet intro.
The average four stroke (Rotax 912 and 914) production over 25 years is 2000 engines/year.
What surprises me is that Lyco make as much as 1500 new aero engines a year. I thought that to be way above current Cessna, Piper, etc production levels. Cirrus are selling more than the others but they use Conti.
What equally surprises me is that Rotax make as few as 2000 a year, given the massive hype surrounding the uncertified scene, with something like 90% of Aero Friedrichshafen showing Rotax based offerings, etc, and the apparent small sales of certified aircraft using these. But it is probably about right, since RVs are AFAIK mostly Lyco based… and there is perhaps a sizeable reason for Lyco’s 1500/year!
Do we really already know this, given that roller tappets exist for only about 7 years? Even the flat top tappets easily make 7 years…
A fair point, and a regularly flown non-roller engine will make 2000hrs over say 20 years no problem, but a non-roller Lyco engine sitting around for a few years (as many are) will prob90 be shagged, so I would by now expect to see some reports from angry customers of roller tappet engines. There are many reports of shagged camshafts in non-roller engines which were overhauled within the previous 7 years, and in all cases I have seen the “hangar queen” explanation was either known or could not be discounted (due to unknown previous-owner activity). I will make some enquiries in the USA…
New Lyco Engines woud not necessarily mean that they come in new airframes, I know a couple of engines that could not be overhauled due to crankcase cracks and thus were bought new.
