Hi Gilles
"Dyn'Aero tried lagging stainless steel exhaust
pipes at the beginning ofthe MCR series, but they quit doing it due
to some corrosion problems."
Was it the 914 exhaust they
tried lagging?
Approx. what year engine was the test performed
on, if it was a 914?
Rotax changed the design of the 914
exhaust over to one that is more robust and made of 309 Stainless
Steel. Lockwood aviation says that most all 914s in Certified
aircraft are lagged without problems and they are an advocate to lagging.
Older style 914 exhausts, like those on a Xamango are lagged and need to
be inspected every 25 or 50 hours, I forget. Not a super trivial job since
exhaust needs to come off to do so. Supposedly if exhaust header breaks
fully, the motor will quit according to my friend who owns Xamango who has
read of several incidents with other Xamangos.
According
to Lockwood, new style 309SS are robust and tolerates lagging well.
I plan to lag my 914 exhaust.
Troy, I can't speak from
experience but the Factory does not recommend lagging 912 or 912S
exhausts. I never saw a Classic exhaust system up close, but if it's close
to an XS exhaust I wouldn't lag it. I am not too thrilled with the 912s
exhausts I have looked at. I would keep a sharp eye on 912S exhaust, and
do it often. Lagging besides instigating differential expansion/ hence
additional stresses will not allow easy inspection.
Ron
Parigoris
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