7000 rpm static - WoW! sounds like not enough
pitch in the prop to absorb the power - tough situation to be in -
NOT!
Regarding your 17" manifold pressure at idle - here is
a comparison of port timing information from Paul Yaw
You can see that the total open time of the PP is
considerable greater than the turbo 13B. So for a given rpm, I would
conclude that since average amount of time the PP intake is open
longer to the atmosphere for the same RPM as a turbo 13B, that the
intake manifold pressure would be higher for the same rpm. So what you
are seeing just may well be "normal" for a PP port.
But then I don't own and have no experience with a
PP.
Ed
Second and Third Generation Turbo 13B
IO 32°
ATDC
IC 50° ABDC
EO 71° BBDC
EC 48° ATDC
Mazda Factory Peripheral Port
IO 86° BTDC
IC 75° ABDC
EO 73° BBDC
EC 65°
ATDC
A
ASThis site is meant to give
information
Sent: Monday, November 15, 2010 9:09 AM
Subject: [FlyRotary] Re: Hey are those 304 Stainless
staples...(from David)
OK, Doug, I'll post my weekend update.
As some of you may know, I have had troubles getting my 20B to run as
it should. Problems started about 3 years back when I decided to
convert from the stock CAS to the Renesis style CAS. While I did have
limited success, it was very sensitive to alignment and air gap of the CAS
sensor, and possibly some other issues that I am not smart enough to figure
out. I had trouble getting it to run above 5800 rpm.
About a month ago I decided that enough was enough and I called Tracy
to say that I wanted my EC-2 converted back to the original
configuration. I sent it back to Tracy who made the mod and
upgraded the software to the latest version. I got it back on
Friday and was anxious to see how it would perform. I installed the
upgraded EC-2 on Saturday. Yea, it started on the third prop
blade and ran quite well, although the Mixture knob was not at
"12 O'clock", it ran very smooth. Following the instructions in
the manual, first thing I did was to adjust Mode
3 to compensate for my larger 60# injectors. Now it was
running really well in the upper rpm/map ranges. A little adjusting of
the lower addresses using Mode 1 & 9 and it was idling
down around 1500 rpm. (Keep in mind that this is a p-port
motor.) The exhaust tone at low idle is hard to
describe...it is enough to send chills up your leg. ;-0
Sunday, after a some more tuning, I got it to where it
would almost do 7000 rpm static. (Keep in mind
that Lockhart, TX is a small country town and this was Sunday
morning. You could probably hear me tuning my engine all over
town.) Confident that it would stay running, I decided it was time to
fly. It climbed out at 6700 rpm as smooth as could
be. There was a 5000' ceiling, so I couldn't climb too high, but
the air was silky smooth. I flew a couple of patterns, climbing
as I circled. At 3500 msl I headed east and did some tuning with Mode
9 at different MAP settings. Up and down the scale, fine-tuning
each address. She was running like a fine Swiss watch, or to put
it another way, like a rotary should.
Issues:
1) MAP Readings - It appears that I may have a vacuum leak as
the MAP at idle is reading 17.4". Next trip to the airport I will
double-check to make sure that I got both lines plugged into the EC-2
properly, and check for leaks elsewhere. It is amazing that
it idles as well as it does under these circumstances. Note
that rather than using a throttle body, I am using a slide-throttle
which is located just a few inches from the intake ports.
So, the vacuum lines are plugged into the unused oil injection ports in
the rotor housings (no oil injection pump). Could
this account for the unusual MAP readings? I do have a
plenum, but since it is open to the atmosphere, I can't measure
MAP from there. I think there are others that use this scheme with
success.
2) Performance - I seem to hit a speed wall at around 2000-2100
prop rpm. I can set the prop higher and get
a higher engine rpm, but the higher rpm doesn't translate into
higher speeds. The speed will gradually start bleeding
off. Not sure why this is happening. Could be tuning, or
intake/exhaust design, or just a characteristic of the M/T
prop. Or, maybe the engine isn't making enough horsepower to push
the airframe through the air any faster. It is annoying though,
knowing that you have another 1500 rpm on tap but can't use it.
3) Alternator - the voltage reading on main alternator is
low. This is a new alternator which has been converted to external
regulator. I'll try adjusting the regulator (again).
All in all, a very successful weekend. As usual, more issues
to sort out though.
Mark S.
Lancair ES, N/A P-port 20B
Lockhart, TX
On Sun, Nov 14, 2010 at 11:20 PM,
<hoursaway1@comcast.net>
wrote:
Rodger
that Doug, I just went through all the paperwork again to make sure all
ducks in a row, then shot one of the ducks & had dinner, a sweet red
wine marinade is the secret to good tender duck you know.
David.
----- Original Message -----
From:
DLOMHEIM@aol.comTo: "Rotary
motors in aircraft" <
flyrotary@lancaironline.net>
Sent:
Sunday, November 14, 2010 7:09:45 PM
Subject: [FlyRotary] Hey are those
304 Stainless staples...(from David)
Na...gotta be 321...don't you think David?! I'm still
hoping to read about some flying exploits from this weekend,
from someone on the list! Surely all our aviators
weren't just sitting around watching football all day like us gimpy /
DNIF guys!!!! :)
Mucho congrats on getting your project to the point of final
inspection prior to first flight! Take your time, be safe, and
enjoy the moment! Then post some pictures / data of the
big event on the list! :)
Doug