Some miscellaneous ramblings on the airbox.
As stated, your engine airbox depends on the year group.
My 1998 timeframe engine also has no brace. The only time a brace is nice
on the non braced airbox mod (done sometime around 2010), is when using a t
hin silicone turbo discharge hose connected to the airbox. (The heavy doub
le or triple braided black hose supplied by Rotax on the old engines was qu
ite stiff and combined with the carb sockets at the manifold and hose clamp
s kept the airbox on securely (nearly all the time with balanced carbs.) T
he issue with the airbox in the old days was it kept sliding off the port c
arb due to oil accumulation. If you flew often, the oil thrown out of the
turbo was but a wisp and if the engine was well tuned it stayed put. If yo
u didn't fly often and the 2-inch hose became oil soaked, then the plenum h
ose to carb would slide off (especially at full boost) and if the carbs wer
e not well synchronized (read as "shaky engine") it slid off fairly often j
ust when you didn't want it to. I found the used 914 I bought had carbs tha
t were no longer a matched set any more due to some wear in the piston thro
at, as the pistons were well out of sync. I bought two new matched carbs a
nd with that carb change, proper tuning, and cleaning my airbox to carb rub
bers, all stayed where put and the engine ran flawless now for 10 years. E
ven after I upgraded the TCU to give me 40 inches takeoff power it stayed p
ut.
If equipped with old oil soaked hoses or a thin silicone discharge hose, or
you left your carb to airbox hoses get really oil soaked, it is prudent to
clean your airbox to carb rubber hose with acetone or similar solvent to m
ake them squeaky clean (or replace them). (Washing your intake plenum out h
elps also.) To assist in security of a shaky engine, a couple of padded hos
e clamps and a piece of sheet metal could hold the airbox firmly to the rin
g mount to prevent slipping. Also, a couple of Adel Clamps and a piece of
tube and bolts could work also on the older manifold without welding on a b
ung like the new airbox has. In a pinch, a piece of safety wire on the por
t side to the ring mount frame at the upper block bolt was also OK at preve
nting the plenum from slipping aft but only temporarily. A nicely made pie
ce of .040 aluminum with a bit of a bevel for stiffness on the edges or a f
lute down the middle and nicely formed ends could in fact hold the box firm
ly in place and at the same time keep it from sliding off. To remove the c
arbs for cleaning, or to flush the accumulation of turbo oil out of the ple
num after setting a long time, it only required removing the bolt between t
he Adels the two carb clamps and it was free.
Once I had perfectly synchronized carb pistons and flew more often, I never
again had an issue. Someplace in the shop I still have my Adel Clamps, a
long bolt and tube just in case because I wondered about this new silicone
turbo hose I added this year and it's contribution to airbox security. Tod
ay my plane has sat for two years due to a wing delam repair and repaint, a
number of upgrades and some other issues my old Classic has, however, toda
y my procedure is to suck the oil out of the turbo cold side before start i
f it has sat (for months) and it seems to run very well. I hope to get the
motivation to fly it again this summer. It's too good of an airplane to j
ust sit. My health is now pretty good, and I just flew a ride with a local
instructor in a 172 and will fly some more proficiency flights to get my a
ir sense back and return to Europa Flying. My civilian CFI says I'm more t
han proficient enough, however, he has some learning to do. There is a dif
ference between currency and proficiency. I've only flown 2 hours in two y
ears with 3 landings in the last 30 days which is not proficiency in my boo
k. Now to take him out and wring out the 172 and get him to understand why
an airplane does certain things and as an instructor know how to rectify s
tudent mistakes.
Have fun guys, the flying season is now arriving. The spring storms will s
ubside soon and adventure awaits...
Bud Yerly
________________________________
From: owner-europa-list-server@matronics.com <owner-europa-list-server@matr
onics.com> on behalf of Roger Sheridan <rogersheridan@gmail.com>
Sent: Saturday, April 6, 2024 8:21 AM
Subject: Europa-List: 914 Airbox Support
Hi Everyone,
I am refurbishing an XS 914 installation & am mildly concerned that the Rot
ax airbox/plenum seems to be only supported by the carb mount rubbers.
During a heavy landing there must be a lot of stress there!
On the 912S installation Europa support their lighter airbox with an alumin
ium strap to the engine frame.
Has anybody added such a support to their 914?
Grateful for any feedback from 914 operators.
Best regards,
Roger
%2Fwww.matronics.com%2FNavigator%3FEuropa-List&data=05%7C02%7C%7C84f98b66
0a7e477ae6c808dc563482d4%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C63848
0030745619292%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiL
CJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C0%7C%7C%7C&sdata=pekNiH4aekpokmv6vQMX0x8z
%2BAQ%2FhkyASsFAy1IIuNw%3D&reserved=0<http://www.matronics.com/Navigator?
Europa-List>
%2Fforums.matronics.com%2F&data=05%7C02%7C%7C84f98b660a7e477ae6c808dc5634
82d4%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C638480030745633929%7CUnkn
own%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXV
CI6Mn0%3D%7C0%7C%7C%7C&sdata=pIFDaJyHKLC7oYyIcmPTi85Htyi1qjz%2Fs1Sv0KcY%2
BZc%3D&reserved=0<http://forums.matronics.com/>
%2Fwiki.matronics.com%2F&data=05%7C02%7C%7C84f98b660a7e477ae6c808dc563482
d4%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C638480030745645261%7CUnknow
n%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI
6Mn0%3D%7C0%7C%7C%7C&sdata=CgfeuqD9hbSfq%2BlHjS0Xuow1v0pJOCJpCK3H5ZubsLg%
3D&reserved=0<http://wiki.matronics.com/>
F%2Fmatronics.com%2Fcontribution&data=05%7C02%7C%7C84f98b660a7e477ae6c808
dc563482d4%7C84df9e7fe9f640afb435aaaaaaaaaaaa%7C1%7C0%7C638480030745656254%
7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWw
iLCJXVCI6Mn0%3D%7C0%7C%7C%7C&sdata=uqtaS4DXZuovWh%2Fc4Q%2BxRZdqti2yxHikuY
ZhdHIBPBQ%3D&reserved=0<https://matronics.com/contribution>
|