Hi! Nic .
Since you think I've been quiet ....... that's a change if ever.
G-PTAG is getting adequate cooling to continue testing without undue
problems
We have done a 5 minute climb at 80 kts and continued at 70 kts without "red
line" problems less than 70 kts the air was stalling which prompted my
addition of the "eye brow,port side" and "underscoop,stbd side " see:-
www.crixbinfield.freeserve.co.uk
I have also added a stand out flange around the exit under the belly to get
some venturi effect ,also some rubber socks in the intakes to ensure no
"trip" to the inflowing airstream, however this has made the removal of the
top cowl more difficult/slower. I am currently overcooling the oil so will
reduce the oil cooler exit air, this should make room for more engine
cooling air to exit.
I am now working on ASI calibration, but the heat question (I hesitate to
use the word problem, please note!) is assisted at present by UK ambient
temps. so I will need to return to that later, probably by making the "exit
channel " into an adjustable cowl flap.
9.25 hours of the 15 hour test schedule now complete, (2.25 hours this
week)so hoping to fly Sunday weather permitting !Three head torque down
sessions (about 2 hours work each time)Currently 15.7 hours on the engine
clock.
Hopefully that's enough for you to digest for a while. ?
Regards
Bob Harrison.G-PTAG Europa/ Jabiru3300
> -----Original Message-----
> From: owner-europa@aztec.houxou.com
> Subject: Cooling out.
>
>
> Aloha, T & C
>
> I've seen many kits at my local EAA chapter with cooling problems.
> It seems that no kit has a cowl designed to hep this problem.
> Big inlet holes are rarely the solution.
> First they must be faired internally at the entrance to flow smoothly and
> gradually into the internal ductwall.
> Even this is rare, with most cowls being cut off in the inside,
> leaving the
> inside lip just hanging there.
> This trips the airflow bigtime and turbulates it, causing (much) higher
> airdrag through the cylinder fins.
> If you have proper ducting in, you still need proper ducting out.
> This is done with augmentation in the engine bay exhaust
> zone-area-port, and
> good cowl sealing.
> Blowing your engine exhaust through the port just right will augment the
> forces drawing cooling air through the cyl fins.
> IMHO, this is nearly the most one can do.
> Cowl flaps can be used to warm up quick, and to prevent shock
> cooling during
> a long desent, etc.
>
>
> We haven't heard of G-PTAG's cooling success.
> Maybe he can help.
>
> Later,
> Nic-xs145 :)
>
> PS- 90 days of 3-man crew construction of my XS monowheel.
>
>
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