Peter, Let me see if I can help confuse the issue a little further.... Taxi tests are not really the best way to evaluate the cooling system. As Scott states below, the lack of cooling air will let things get hot regardless of your set-up. To your original question regarding cooler placement, I have found the location forward of the #2 cylinder to work quite well. I use a SW10599 which has very good heat transfer at a fairly low pressure drop. I even have the exit necked down to about 5 sqin. I have however heard of other cooler makes/models being more problematic. Many details will determine the final outcome.
Chris Zavatson N91CZ 360std
Sent from my spiffy iPad
Peter,
I did not mean to imply your cooler installation will not
contribute to the problem - in flight you will expect high speed air to make an
almost ninety degree turn. The assumption is that the upper cowl
pressure is greater than the lower cowl pressure to force sufficient air through
the cooler. That is even while the air is being tripped over the vanes at an
almost 90 degree angle. At slower speeds (fast taxi tests), neither the
pressure differential nor the turning of the air is as much of a problem.
Grayhawk
Grayhawk,
I
will give the rudder a chance next time. Can just not imagine that it will
have such a big effect but –
I
read out of your words that there is nothing wrong with my cooler installation
in front of cylinder 2. I did not check engine timing – again – I did it some
time ago during building process, assuming that it will not change by itself….
But again – good tip.
Thanks,
Peter,
D-EPSO, 360 MK II
Von: Lancair Mailing
List [mailto:lml@lancaironline.net] Im Auftrag von
Sky2high@aol.com
Gesendet: Dienstag, 11. Juni 2013
15:47
An: lml@lancaironline.net
Betreff: [LML] Re:
Groundtesting problems
300
series Lancairs have a very strong left turning tendency (P-factor, weather
vaning, etc.). Even the engine mount has the engine canted to the right
to compensate. The small rudder does not have much effect below 40
KIAS. Yes, you must tap the right brake often on a take off roll when
below 40 KIAS and power must be applied slowly until enough speed is gained
for the rudder to be of some help. It is useful to lighten the load on
the nose gear as you speed up.
There
is not much cooling at the lower speeds used in taxi tests. Also, new
engines generate more heat from internal friction before break-in. I
don't have enough information to comment on your cooling system, but 200F
(about 100C) oil temps and close to 400F (about 200C) cyl head temps are not
that surprising depending on conditions of hi power, slow speed
tests. Have you checked engine timing?
Hello
friends,
I am in the pre-first-flight phase and suffer some problems.
I would
appreciate valuable hints to the following issues:
- being
on the runway and pushing the throttle forward I have to constantly
brake
on the right side not to leave the runway. Is that "normal" or up
to
which extend is the latter tolerable ?
- I have my oil-cooler in
front of Zylinder 2 facing downwards. I have a
plenum to seal the
incoming air. I placed a small cover over the cooler to
guide the air
downwards for cooling purposes. The remaining air is going the
Zylinders
2 and 4. Unfortunately CHTs are still very high (>200 C)
and
oil-temperature is after going the runway 4 times up and down (1,5
Km) more
than 100 C. This is definitely to much. Outside temps are appr.
13 C. What I
am doing wrong? Any experience with forward placed coolers ?
Recommendations
?
Thanks a lot in advance,
Peter
LNC 360
MKII, O360 F1A6, D-EPSO
--
For archives and unsub http://mail.lancaironline.net:81/lists/lml/List.html
|