Dave;
Thanks for that. I think you’ve
identified the issue exactly. I have been doing the leaning based on the
highest EGT, the one that shows on the EM2 front page; and have not looked at
what the others are doing.
I have noted in the past that the EGT
spread was different for different conditions, and I now recall that during the
dyno tests I had noted that EGTs were not necessarily all on the same side of peak as the
mixture was varied – that #1 and #3 might move in different directions.
Always one more thing. I guess it
will give me something to do while droning over the empty spaces in Wyoming.
Al
-----Original Message-----
From: Rotary motors in aircraft
[mailto:flyrotary@lancaironline.net] On
Behalf Of David Leonard
Sent: Thursday, June 26, 2008 7:08
PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: Running
lean of peak
Hi Al,
I would confirm your experience. It will continue to run 200 LOP, but
even at 100 LOP it is starting to have significant misses. Even 50-60
LOP has a much rougher feel than ROP, but the EGT's really start to fall
off and fuel consumption drops.
I have noticed that much of the problem is rotor balance. If one rotor is
20 ROP, the other may be well LOP. If I carefully work to match the
rotors then I run much smoother well LOP. The problem for me is that my
rotor balance is very dependent on RPM. If I get them matched at 5000
RPM, then they are WAY different at 6000 RPM and vise versa. (evidence of a
very poor manifold design?!)
For my next turbo destruction cycle, I plan to really focus on EGT (like cert
engine pilots have to). I will balance the rotors at a particular RPM and
only run LOP at that RPM. Otherwise, I will run ROP. If I can get
the turbo to 500 hrs, that would be less than $2/hr and it would be worth
it. Keep 2 turbos in cycle to the rebuild shop, and always the means to
fly around n.a..... I'll let you know how it goes :-)
Dave Leonard
On Thu, Jun 26, 2008 at 7:25 PM, Al Gietzen <ALVentures@cox.net> wrote:
How many hours are on your sparkplugs and are you
useing auto fuel or 100LL.........Something to
consider before a 2000 mile trip.........Could be
possible indication before the dreaded "SAG"..........
I don't recall (have to
check the engine log), but I'd guess maybe 20 hrs; only 10 ga 100LL; all the
rest unleaded mogas. I took a leading and trailing out yesterday to look
at them and they look fine.
Al
--------------
Original message from "Al Gietzen" <ALVentures@cox.net>:
--------------
I'm finding that at about 100F LOP I sense that the
engine is starting to not like it – like it doesn't seem to be entirely
smooth; maybe an occasional miss here and there. Am I right that some of
you guys run as much as 200 LOP; or is it my imagination – in both cases.
Would timing setting have much of anything to do
with running LOP?
Just past by the 100 hr mark on the engine near the
end of a 500 mile trip on Monday. I plan to leave next Monday on a round
trip of over 2000 nm over the following week. That'll rack up a few
hours.
Al
--
David Leonard
Turbo Rotary RV-6 N4VY
http://N4VY.RotaryRoster.net
http://RotaryRoster.net