|
George,
Your
postings are quite surprising, and a bit disappointing. You point out that
auto plugs are different that aviation plugs. You point out that you know
the temperature of the aviation plugs during operations. You point out
that auto plugs enjoys a heat sunk environment. You point out that the
aviation plug was designed for the aviation environment.
All of
these are true, but unfortunately, you leave us to 'conclude' that that somehow
means that the auto plug are unsatisfactory in the aviation
environment. I don't like having to bridge such gaps in data.
What is it about auto plugs that are inadequate? Peak temp
tolerance? Temp rate of change? Cylinder compression? 100LL
gas? Where do they fall short, other than they are 'different' from
aviation plugs?
Personally, I run aviation plugs on both my mag and EI, but many have run
auto plugs without problems. Why, or how, were they successful when there
are so many implied deficiencies with auto plugs?
Thanks,
Chuck
Jensen
Colyn,
Other than curiosity - - it is not,
frankly, important that I know what the number is supposed to be - -
What is important is that nobody has a clue
as to what the number is for the automotive spark plug mounted in the
aircraft application.
Keep
in mind that the automotive spark plug enjoyes being "heat sunk" into a
massive water cooled cylinder head that is held at constant temperature from a
thermostat.
By
contrast, the aircraft spark plug is desgined for the much more variable
environment of the air cooled cylinder head which can have temperatures more
than twice as high as the automotive cylinder head.
There is a casual acceptance of a substantial
level of "under-investigation" that is associated with
some of these often routinely accepted recommendations to use components
that have not undergone thoughtful testing at the boundary
conditions of realistic operating
environments.
Regards, George
PS> The answer to your question is in some
of the APS class materials. We made a power point slide that detailed
the aircraft spark plug ceramic temperature as a function of A/F
ratio.
George said
I can tell you the answer to that question with
respect to an aviation spark plug.
okay, what's the answer? say, 50 dF LOP 32" TSIO-550
....or whatever you actually have.
|