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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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