Hi Valin and Allyson,
I have an IO-550 EXP engine from Performance Engines with one Lightspeed
Plasma III electronic ignition, one magneto with impulse coupling, 8.7:1
compression ratio pistons, and ram air. I'm have 150 hours on the
engine.
I've been very happy with the support from Performance Engines. The
electronic ignition and the magneto have been completely trouble free.
(This is pure speculation, but I wonder if the repeated problems a
few have had with electronic ignition is related to installation issues;
I've heard that they don't like too much heat?)
I'm happy with my decision to go with one electronic ignition and one
magneto and 8.7:1 compression ratio, but I might have been equally happy with
two electronic ignitions or two magnetos and high compression pistons. I
can make a good argument on both sides of this debate.
If I were doing it again, I'd eliminate the ram air option and instead go
with something like the system developed by Steve Colwell (search the LML for
details). The ram air only gains you about an inch of manifold pressure,
and some of that gain may be due to bypassing inefficient air flow
through the diverter when the air filter is selected. Ram air may also
cause problems running lean of peak.
I'd also use Scott Alair's method of providing higher pressure air to the
fuel injector vents. It's a low cost, light weight solution
that seems to allow operating lean of peak when using ram air.
(Search the LML)
I installed Andair's gascolator and air/oil separator, and both have been
trouble free.
I used Barry rubber engine mounts (ACS part #94011-20) because the Lord
mounts were out of stock when I ordered. At Lancair flyins, I noticed
that most engines had sagged so that the prop spinner was lower than the
cowl. As a result, I installed my engine a little high so that
when it sagged, the prop spinner would line up with the cowl. Well, I'm
still waiting for the engine to sag, which means I'm the only one at a flyin
with the prop spinner higher than the cowl. I don't know if that is
because of the Barry mounts instead of Lord mounts. (Actually, my engine
has sagged some, perhaps half of what it needs for the spinner to line up
with the cowl. Maybe it will be at the right height when it's time for
overhaul?)
Best,
Dennis Johnson
Legacy 150 hours, leaving for Alaska next Monday