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I'm with John on this. One drop of oil coming out
of the cowl will obscure the canopy. I have first hand experience with this
in a Cessna 140 I used to fly. It had a leaking prop seal and just a couple of
drops completely coated the windscreen. Had to look out the side window to
land it.
Mike Wills
----- Original Message -----
Sent: Sunday, September 20, 2009 5:13
PM
Subject: [FlyRotary] Re: Another mixed
day / Cooling experiments
Tracy, any oil leaks will be self evident on the
windshield and a constant pain to clean, so I would advise against any
discharge on the cowling top. JohnD
----- Original Message -----
Sent: Sunday, September 20, 2009 6:51
PM
Subject: [FlyRotary] Re: Another mixed
day / Cooling experiments
"No air
pressure under the cowl?? What is the pressure drop across the
radiator? What is the zero pressure referenced to? If it is the
cockpit, you may have pressure in the cockpit causing the difference to be
zero. "
It was not zero but
low. about 1.2" H2O. This is at 120 MPH BTW.
This was with cowl flap open. The reference is to the aircraft static
system so it should be accurate. Have not measured the front side of
heat exchangers yet but I assumed diffusers were working well based on cowl
off flight test. Will have to verify this of course.
Just
finished the VG flight test. No measurable difference.
Also
flew with the inlet fairings off (which enlarges the inlets a bit).
Slightly better cooling but not the answer.
I'm trying to
restrain myself from chopping up the cowl to install the louvers. I
can't see how they would help much, especially on the bottom of cowl.
Maybe on the top? Somebody STOP me!
Tracy
On Sun, Sep 20, 2009 at 3:09 PM, Bill Bradburry <bbradburry@bellsouth.net>
wrote:
No
air pressure under the cowl?? What is the pressure drop across the
radiator? What is the zero pressure referenced to? If it is
the cockpit, you may have pressure in the cockpit causing the difference
to be zero. It the pressure under the cowl is truly zero, there will
be little or no velocity of the flow out of the cowl so VGs will not
help. Al? said he had his cowl pressure at 5 inches to help
speed the air back up as it goes out.
Bill
B
From:
Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Tracy Crook
Sent: Sunday, September 20, 2009 9:03
AM
To: Rotary
motors in aircraft
Subject:
[FlyRotary] Re: Another mixed day / Cooling
experiments
"It IS seeping from the filter seal and NOT
the two hose connections...no doubt on this.
"
Just from observing many rotary installation
'de-bugings' over the years (including my own) I noticed that difficult to
solve problems are almost always caused by false assumptions.
It is
possible to get several bad filters or two bad filter mounts but the
mathematical odds are staggeringly small. You haven't offered
your test proofs as to why you know they are bad and leaking but if I were
betting, I'd put my money on something else. The assumptions about
the wiring might need examination as well.
This reminds me of an
oil leak the Ed Anderson had. The oil was showing up on the back
side of one of his rads. There was an oil line running very close
(< 1" as I recall) to the rad so the assumption was made that the oil
line was leaking. Long story short, the oil leak was actually coming
from something at the opposite end of the engine. What exactly was
it Ed? It defied all logic in that it was not even close to where it
showed up and the oil was traveling against the assumed airflow under the
cowl.
Speaking of assumed airflow, my cooling
experiments are blowing away all my own assumptions. I kluged up
the cowl flap I mentioned and fixed it in the open position. The
trailing edge of outlet is about 1 1/2 " below where it was.
The temperatures were down a little but not near what I wanted. Only
a little better than the big giant opening I tried. At this point I
was ready to conclude that the underside of the airplane was bad place to
put a cooling outlet. Keep in mind that my working assumption is
that the pressure under the cowl is too high to allow good airflow through
radiator and oil cooler. I had installed a pressure probe under the
cowl but forgot to look at the reading. Figuring I might as
well know how big a problem I had, I made another flight to check the
under cowl pressure. Duhh, almost nothing! Checked the
probe to make sure it was not blocked, pinched, etc, and everything looked
OK. I need to check pressure in a few other spots to be sure
about this. There is something odd going on with airflow under the
cowl but I'm back ti head scratching mode again.
One builder on the
RV list said he got a big improvement in cooling by installing VGs on the
trailing edge of the cooling outlet. This is so non-intuitive that I
can't imagine why it would work but its so easy to try I might have to do
it while scratching my head.
Tracy
.
On
Sun, Sep 20, 2009 at 1:37 AM, Chris Barber <cbarber@bellairepolice.com> wrote:
Made it out to
the hangar for most the day and decided to take the advice here and modify
my start up routine based on what was suggested here and in the
manual. So, I cranked the mixture full rich with no priming and it
started up in a few blades. Ran for a while, shut down and started
back up with mixture in about the 2:00 oclock position....and it started
fine. Kewl.
The first bad news is that I
replaced my romote oil filter mount and installed a new filter. As I
have mentioned here I have had it leaking at the rubber filter seal.
The old one looked ok, but since replacing the filters no less than three
times and knowing that the eye cannot see all inperfections, I
replaced the mount AND filter (K&N 2004 filter). But, NO JOY. It
is still leaking where the filter mounts. It IS seeping from the
filter seal and NOT the two hose connections...no doubt on this. I
know the rotary's oil pressure is higher than other engines but I would
not think it would be so much that it is overwhelming this standard mount
and seal. This is just a standard screw on remote oil mount made out
of AL...Made in the USA. Looks like many others I have seen.
Y'all have any ideas.
Second good thing is a guy
from a few hangars down turns out to be a welder by trade. He came
down as I was working on the new stainless turbo exhaust manifold the
other day after offering to help me modify my manifold.. As was
mentioned here before, the old cast iron manifold I had wold work if
mounted upside down. It puts the turbo lower (the oil return being
about 2 inches higher than the oil inlet return in the pan) to the rear of
the engine and it clears my aileron control link. I will have to
make a very small modification to the lower cowl to give me proper
clearance EXCEPT the wastegate interfeared with the Mistral intake fuel
rail. So, I ordered a stainless copy of the cast iron one I had,
based on John Slades suggestion. My welder friend said it would not
be too big a job to turn the wastgate extension around which should allow
it to miss the fuel rail completly. We looked at the options and he
took the manifold with him saying he would cut off the old wastgate
extention and come back to fit the new part on in a few days.
Kewl.
The
second bad news is that I was doing some continued tuning. I even
transferred A to B as B was a bit rough from the factory and it worked
fine. HOWEVER, later in the day, after feeling pretty good about the
lasted progress (excepting the continued leak) the engine stopped.
Huh? It will not restart. I checke the first fuel filter and
it is clear. I decided to start at the beginning and just run the
EC2's diagnostice test. Damn, no chattering of the injectors (even
though I was able to hear an individual click when I primed it). Put
on a test plug and wire and got no spark. All the other
electrics are working fine.
I
pulled my extra EC2 out and installed it and I got injector clattering
away and spark on three of the inectors. The secondary on Rotor one
did not seem to fire. Hmmmmm? I put on an extra injector that
I had and tried again, and it didn't fire...then fired for a few seconds
and then stopped. Looks like I have some more wire issues. Damn, I
though I had really gotten past most of those.
I am
really confused about the EC2 seeming to just shut down. The other
electrical componants are all working, but the EC2 componants are
not. Strange since I thought each items (injectors and coils) had
there own power source thus should not shut down as a "team" like
this. Yes, it is the same on A and B. Currently I am very
discouraged so I stopped for the night and decided to crawl into bed with
a hot blond and sulk (she was actually gracious enough to hang out in the
hangar with me for a few hours...whata gal)....well, she helps me from
sulking too much.....this dating in my 40's ain't all that bad
<g>
I
anxiously wait commentary and possible explanations from y'all. Upon
my return to the hangar (today was MY Sunday) hopefully tomorrow
night after work I will be looking at my, apparntly piss poor,
wiring.
As
always my friends, Thanks.
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