Having got four EGTs, I find that (as the rear cylinders run much cooler) I
could live with only two EGTs. But then I would probably be wondering what
the two rear cylinders were up to; so who knows.
The firing order of the 912 means that the rear cylinder follows the front
by a delay of 180 degrees only (as opposed to 360 deg. for evenly spaced
firing).
That means that the intake of both cylinders on one side are overlapped (the
valves are both open together for a short while in the cycle, one at the
beginning of the intake stroke and the other at the end) and I suspect that
one cylinder is effectively "robbing" the other. Roll-on injection and
four separate runners! (is that not what the alternate drilled and tapped
bosses around the cylinder head intakes were provided for?).
Duncan McF.
----- Original Message -----
From: "Graham Singleton" <graham@gflight.f9.co.uk>
Subject: Europa-List: Rotax 912ULS EGT
<graham@gflight.f9.co.uk>
>
> >Very true. When the interior of my 912S silencer collapsed it was only
the
> >very high EGT that flashed up on my EIS (Brilliant) that stopped me
damaging
> >the engine. I would be reluctant to fly without in future.
> >Rick Morris G-RIKS
>
> I agree
> in fact I would prefer 4 EGTs not two. The way the highest cylinder moves
> around with changing throttle setting is amazing, Must be something to do
> with the strange manifold shape. I suspect the Skydrive carb heater might
> help to even out the mixture and help more balanced EGTs. Anyone know?
> Graham
>
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