Lieber Graham,
wie geht es Dir ? Ich hoffe Du kommst bald nach Wien - im Moment haben wir
keinen Schnee...fuer die naechsten 3-4 Wochen....so hurry.....
I am currently doing taxi tests. More or less high speed (30 kts). All seem to
be OK but I still have a few excuses for not to fly...Beside I am still on a
diet to compensate for my heavy building...so no APFELSTRUDEL and no
PALATCHINKEN!!
After rolling about 40 minutes with 2000-3000 rpm I get quite high under the
cowling temperature of 50-60 C near the carburators and 60-70 C at the
mechanical fuel pump. (I have installed temp sensors on the back of each air
filter and on the mechanical fuel pump) Outside temp was 23 C and oil 110 C and
water 100 C (glycol with 40% water). My oil cooler is mounted just below the
spinner and my exhausts are wrapped with Thermo-Tec insulation wrap. At this
temperatures static rpm went down to 4800-4900rpm compared to 5000-5100rpm when
engine is cold (17 tip of blade).
I suppose that cooling will improve when flying but on the ground it is not
quite optimal.
After 40 minutes ground tests I shut off the engine for half an hour...Even
after 30 minutes under the cowling temp is still more than 70 C. When starting
again under this conditions I got vapour locks - as expected - after 30 sec
running and engine went very rough and stopped. However vapour locks stops
immediately with electrical fuel pump on.
I think that the fresh air inlet/box would definitely be an excellent
modification and I would like to know how far is it?
I am also looking for a variable pitch prop, sooner or later. Any new experience
with the Arplast (vibration, motor etc.). Would you recommend the Arplast or has
EUROPA better experiences with any other propeller ?
Thanks for your advise
Klaus
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