Randy,
What you said is, of course, contrary to my experience and the
recommendations made by Light Speed Engineering.
Which plugs had "the tips burns down fast or the ceramic crack under the
pressures" and what were the pressures? Were the plugs ever
dropped?
Are you sure the coils shorted internally because the auto plug gaps were
getting larger or were the coils placed in too hot of an
environment? What plugs were used? It is hard to
imagine internal coil arcing in the absence of any plug gap or even the
absence of a plug altogether.
Which actual auto plugs cracked under full power and/or had the
electrodes burned away? What were the other engine conditions?
I have run my 9:1 CR injected 320 at takeoff power (racing is like that)
for hours on end with no difficulty - no difficulty with either the EI or the
Denso IK27's - where the timing and A/F ratios have been appropriate for the
power and the coils are located in an area behind the engine that
usually reaches 70C.
You may wish to poke around the web for info on the differences betwixt
Champion and Unison (Autolite) iridium plugs.
BTW, I noticed that you re-gapped your aviation iridium plugs (out
of the box the gaps are too small for EIs, .016-.018.). This is a very
difficult task with Champion plugs (they are happy to re-gap them for
you).
Finally, I didn't even try the LSE recommended W27EBR (27 heat rating for
higher compression engines) since they seemed too cheap. I did try the
W27EMR-C plugs (triple massive electrode), but didn't like them because I
could not control all three gaps (well, that was one reason).
Scott
Krueger AKA Grayhawk
Lancair N92EX IO320 SB 89/96
Aurora, IL
(KARR)
Pilot not TSO'd, Certificated score only > 70%.
Not even
FAA tested for Repairman Certification.
In a message dated 5/25/2008 7:24:32 A.M. Central Daylight Time,
randystuart@hotmail.com writes:
In my 360
I use
Iridium plugs with my Jeff Rose EI. They work great. Set to 035.
I wouldn't use car plugs
in an aviation engine. They don't work well.
I've seen the tips burns
down fast or the ceramic crack under the pressures.
One multiple failure I've
seen is on a friends very low time Legacy that has had 3 shorted coils on
his LSI system.
This was from the Denso
auto plug gaps getting larger from wear then eventually arcing inside the
coil.
Another failure in a 360
I've seen from auto plugs is the ceramic cracks under full power and
completely burns away the electrodes, damaging the
cylinder.
Aviation plugs are made
for aviation use and can take the abuse. They last much longer and rarely
fail. All the Lancair's in my group stopped using auto plugs.
Uppers are Massives with a
mag and lowers are Iridium with an EI.