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I just sent a post asking Lynn to explain the .010 gap. I still had
his original e-mail in the in-basket and have just re-read it - I don't
understand the reference to "secondary ignition breakdown" and "secondary
breakdown" in the 2nd paragraph, "One quick check for secondary ignition
breakdown, is to quickly install two new plugs in the leading holes, gapped at
.010". If the problem is still there, it is less likely the secondary output. If
the problem is gone, it is likely the secondary output."
Please help an old timer used to "coil and distributor ignition systems"
who is a "first time owner" (and VERY HAPPY user) of a modern (1993 & 1995
Ford Escort) ignition system:
. . . Are these new "ignitor blocks" still using the
"primary"/"secondary" coil principle of the old round coils? If so, what
makes these 1990's and later "high energey" systems "higher voltage"?
Higher ratio of primary to secondary coil windings? (or vice versa?) and/or the
totally mysterious "ignition modules" that go along with the coil packs?
I.e., are the square coil/igniter coil blocks doing the same thing, only better,
than the old coils?
. . . If so, then is Lynn's ref to "secondary ignition breakdown" a
ref to some kind of failure or degradtion of the secondary coil windings? (such
as internal shorting of sec coil windings to each other, so as to reduce
"effective" number of coils in secondary; or, arcing of secondary to engine
mount/block) so voltage to plugs is significantly down?)
Also, why put the .010 plugs only in the leading holes, as opposed to
trailing, or both holes?
David
----- Original Message -----
Sent: Tuesday, May 23, 2006 8:35 AM
Subject: [FlyRotary] Re: Another case of
heat-soaked coils?
In a message dated 5/23/2006 9:27:40 A.M. Eastern Daylight Time, lors01@msn.com writes:
John did tell me that the threshold of 'splutter' was around 38" Hg
MAP. Since the engine quickly went down hill even at lower throttle
settings and he thought it was only running on one rotor at the end of
testing, I suspect there are a lot of clues to what is wrong other
than the 'splutter' at 38". We just don't know what they
are. The coils being bad is a long shot since it would mean that two
of them died at once, not likely but possible.
Did the engine run well after cooling for some time? Not enough
information.
One quick check for secondary ignition breakdown, is to quickly install
two new plugs in the leading holes, gapped at .010". If the problem is still
there, it is less likely the secondary output. If the problem is gone, it is
likely the secondary output.
The lost spark coils of later RX-7s fire twice per revolution. They fire
both of the leading plugs twice for each revolution. So they work with very
short rise times. At 6,000 RPM that's 12,000 cycles per minute. Try that with
a Corvette coil.
Even so, ignition problems at 6,000 to 6,500 RPM should not be happening.
We shift at 9,600 RPM, and with two MSDs even going a bit lean at the top
causes a minor misfire or skip. Re-gap the plugs to .010" fixes that every
time.
Also reducing throttle setting slightly restores good ignition
performance when this is the problem.
Stock Rotary engine coils are very good. The lost spark coils are
better.
Using two lost spark coils, one for both leading and trailing on each
housing would be as close to bullet proof as is possible. The trailing must be
distributed otherwise.
If Tracy's controller can light a stock (lost spark) coil, that is.
Lynn E. Hanover
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