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To all:
I had a very similar experience without knowing it. My Lancair IV just went
through an IO550 to turbine conversion. My 550 had a 5 year old ram air.
Upon removing the ram air from the engine we found that the butterfly had
come loose and wedged in the ram tube, just as your did. I did not
experience any engine symptoms so I guess I lucked out. No telling how long
I had been flying that way.
Berni
-----Original Message-----
From: Lancair Mailing List [mailto:lml@lancaironline.net] On Behalf Of Paul
Bricker
Sent: Friday, July 20, 2007 7:45 AM
To: lml@lancaironline.net
Subject: [LML] Ram Air Oops
People,
Not to cause a panic but I feel I should pass on my recent experience. Tim
is preparing a Service Bulletin that I expect out soon.
A few days ago I installed my Ram Air system on my ES. At that point I had
about 28 hours on the engine and felt I had a good baseline to compare. I
flew it about three hours over the next two days. Today during run up I had
a large (for a LightSpeed ignition) drop on one ignition system, and
returned to the hanger to investigate. Pulling the plugs I found the top
plug in #5 bent closed (the LS ignition used plugs that look like automotive
plugs). On further investigation I noticed that both of the screws holding
the butterfly to it's' shaft in the Ram air system to be missing, and the
butterfly cocked a little sideways in the ram tube.
Talking with Tim he stated that these should have been coated with LocTite
and peened. Today they are made in house at Lancair and that is the process
they use and inspect to. I bought the Ram air several years ago (Tim is
checking exactly when for applicability of the service bulletin) and mine
was probably one previously made for Lancair by an outside vendor.
I bore scoped the engine and saw damage in #5 only (I guess this is good). I
yanked the jug and piston and at the moment they are in the engine shop for
evaluation and repair in the morning. There are 20+ marks on both the piston
and the cylinder head, but it appeared to me that the plugholes and valve
seats had been missed. Until they look at the head more closely, including
the surfaces of the valves and seats, I won't know how much damage was done.
While they are doing that I will pull the whole induction system to make
sure the other screw isn't still waiting around for its moment of glory.
I hope I have the one and only Ram Air that had this defect, but I'd advise
inspecting yours before you fly again. This isn't that hard to look inside
at the butterfly. (On the other hand, tightening those screws without a
special tool is tough. I think Tim is developing a fix/preventative action
for the Service Bulletin.)
My plan to leave Monday for KOSH is probably out the window, but given some
good luck the engine should be running again tomorrow pm and then I'll see
how long it takes to get back sufficient confidence to leave on 3000 nmi
trip. Hope to see many of you there.
Paul Bricker
N63PB
LNCE
IO-550-EXP
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