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