rparigor@suffolk.lib.ny.us a crit :
> Was it the 914 exhaust they tried lagging?
Among others, yes.
>
> Approx. what year engine was the test performed on, if it was a 914?
Beats me.
I believe that was in the pre-2000 era.
>
> 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.
I don't know what Ximango exhausts look like.
During our build I payed great attention to what is going on under the
cowling, esp. concerning heat.
In my opinion - but I know Europa-philes are wary of non-Europa opinions
;-) - lagging is not the best response to radiated heat from exhausts,
just like ceramic coating, etc..
Within a few minutes, the lagging material is just about the same temp
as the exhaust, and radiate about just as much as bare metal.
As mentioned the best way to drastically cut radiated heat is to install
light radiation shields, et allow free air passage.
Of course, it is up to each builder.
Best regards,
--
Gilles
http://contrails.free.fr
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