Jim,
I’ve seen many pictures of your
plane – beautiful.
Any data on the (nominal) LOP CHT’s
associated with the cylinders that failed?
How many degrees LOP? My
understanding is that more lean is generally better (i.e. cooler) – at least
on the margin (i.e. you’re best to be either rich enough or lean
enough. Peak is square is the red box)
What engine monitor do you use?
Rick
ES: TSIO-550 building
From: Lancair Mailing List [mailto:lml@lancaironline.net] On Behalf Of JIMRHER@aol.com
Sent: Thursday, September 14, 2006
9:42 AM
To: Lancair
Mailing List
Subject: [LML] Backfires LOP
Phil
wrote;
Anyone had experience with this?
Pilot flying our IVP (TSIO550E3B with 4 blade MT) and reports:
"Had backfires(?) couple of nights back. Was running lean of peak with
temps 1590 at FL150, around -15C, light rain, 29Hg 2500rpm .
Happened twice so went rich of peak for remainder of flight with no
problems. Any reason come to mind?"
Be grateful for any thoughts
Phil Sexton
Melbourne
I
have had one backfire (afterfire) that got my attention while going LOP. I
have a 4P with TISO 550E. I had about 30 hrs on a new overhaul and was just
going to test it LOP. Previously, I had 300 hrs on the 4P with about 50 of
those hours LOP. So when I tried it, just like in the past, it gave one big
pop. I didn't try that again. But while looking for why I had a strange
vibration in this new engine I found that one injector had a piece of dirt in
it and it caused the EGT for that cylinder to run slightly higher than the
others while ROP. After cleaning the injectors the vibration was gone and the
LOP works correctly again. Without GAMI's, which I should have anyway. The
engine will pop if too lean, and in this case one cylinder got too lean. I
wouldn't just accept that this would not do any harm. I have heard of very bad
things happening if it blows off a hose from the Turbo. Like loss of
pressurization, engine stopping and won't start at that high altitude, etc.
As a
side bar, I don't run LOP anymore unless I need to stretch the range. This
after replacing all 6 cylinders at 215 hrs from new and then the second set
after only 82 hrs. Both times the exhaust valve stems and guides were out of
serviceable tolerance. This could be a very long thread but will have to wait.
Also,
I lost one Mag, from water in the cap from pressurization moisture, just like
Carl Cadwell said. But mine didn't show up in the air, it just wouldn't work on
the next flight Mag, check. I have since Inspected the Mag. every 100 hrs.
There is a very small weeping drain hole in the high voltage cavity that can
and did get plugged.
Jim Hergert
L4P, N6XE
(An Sexy)
408 hrs.