2nd update on Review of Plasma II Ignition System

This is my 2nd update on the Lightspeed Plasma II Ignition System, making a
total of 3 posts in 3 years. (To see the original post and 1st update, go to
GOOGLE Groups, and type in *** with the quotes ***

"Review of Plasma II Ignition System"
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In this update,

- Hall Effect Module finally weeps
- Hall Effect D-connector problem
- Denso Iridium's - no change
- New W27EMR-C spark plugs
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Hall Effect Module

Am tardy once again posting this. Back in February, we hit 500 hours on the
Plasma, and unfortunately, the Hall Effect Module started weeping a little oil.
Called Klaus. Customer service has greatly improved. He said I was the first
to report the weeping seal, probably because we were the first to accumulate
500 hours on the newish Hall Effect Module. He asked that I send the unit to
him for evaluation. Turn around was one day - he ended up replacing the shaft
and oil seal. He said I could replace them myself next time, but since he
heats the unit up to 350 degrees to remove the shaft (press fit) I think I'll
let him do it again if there's a next time.

I'm not sure why the Module started weeping at only 500 hours. Seems low to
me. FYI, we change oil every 35 to 40 hours, have a spin on filter, and
blow-by is commensurate with 1500-hour cylinders. (A quart every 4 hours.)
With the previous "electronic" ignition I was testing, which used a similar
hand crafted magneto type pickoff unit, its seal lasted 1000 hours. But once
it started weeping, no amount of replacing the oil seal made any difference.
(I.e. it probably needed a new shaft too.) Contrast this to our old Bendix
mag, which has 1900 hours on it since we've had it, and who knows how many
hours before that. Our mag does not weep oil. Not sure if Bendix uses a
different seal paradigm (slinger) or if this is a metallurgy thing with the
composition of the shaft.

You're supposed to inspect your Hall Effect Module for oil weep every 100
hours. With our sample of one, you may want to be extra diligent around the
500-hour mark.

Hall Effect Connector problem

There's a 9 pin "D" connector on the back of the Hall Effect Module. When I
reinstalled the Hall Effect Module after sending it to Klaus for repair, I
noticed the D-connector was intermittent when I tightened its screws. To make
a long story short, it seems as though the pins in the male were "bottoming
out" and causing an open in the Module. It seems impossible to solder a new
female connector on the PCB - Klaus has some kind of thick epoxy looking
"Humi-seal" stuff on the PCB. I ended up using some small washers as spacers
between the flanges of the connector, which keep the male from bottom out into
the female. Kind of hokey, but it works.

Iridium Fine Wire spark plugs

I tried a set of the Denso IK27 "Ultra-Fine (0.4mm) Iridium" plugs that Klaus
recommends for the ultimate. The hype from Denso is "The smaller the
electrode, the more concentrated the electric potential. The stronger the
electric field, the lower the required voltage. As a result, combustion is
good for all types of driving... " The theoretical physics is correct. In
practice, I couldn't tell any difference. It's not like I was suddenly able to
lean further with the fine wires. That is, I didn't notice a "night and day"
difference.

The Iridium's are expensive, and the retailer I bought them from warned not to
gap them. (Worried about breaking the center electrode.) I opened up the gap
a bit anyway, figuring the small electrode should allow the larger gap without
straining Klaus' coils too much. But I didn't notice any real improvement.
Maybe if I opened the gap to 0.040" there would have been a noticeable
difference. (We're running half point higher compression, and Klaus says max
gap of 0.034" for us.)

I suspect Klaus' system develops such a hot spark that "just a little hotter"
is into diminishing returns. Perhaps if you're racing at Reno these things
matter, but I'd advise saving your money. The only variable I haven't measured
is longevity of the Iridium's. They cost me 4 times more than standard plugs.
If they last 4 times longer, I suppose they might be worth it. I only put 100
hours on ours so I don't know how they wear.

New W27EMR-C spark plugs

In the meantime, Klaus has changed his recommendation for standard plugs.
These new plugs have a "cut back" electrode, which is supposed to expose more
of the mixture to the flame. You could cut back the electrodes on the old
plugs with a grinder and achieve the same effect. But the other selling point
of these new plugs is the solid terminal. No matter how hard I tried to stake
them on the old plugs, I couldn't keep the terminals from rotating loose.

Again, I can't tell a night and day difference from the old plugs - they're
possibly a little better allowing slightly more aggressive leaning, but it's
not like I did a double blind experiment. But the solid terminals are
definitely worth having.

One thing I don't understand - Klaus recommends the 27's for standard and high
compression engines, and 24's for low compression. This seems backwards to me.
The Denso temperature code is backward from most convention, so 24's run
cooler than the 27's. It seems to me that a high compression engine should be
running the 24's - the cooler plug. In any event, we run the 27's at 9:1 and
they seem to run at the right temperature.

Errata

I had tried some shielding of the coils for RFI prevention. I had taken copper
foil and soldered a conformal shield around each coil body. [We have three LF
radios - an ADF, a Stormscope and a LORAN. Okay, okay - they were state of the
art when we were building the plane. grin] I sent a coil back to Klaus for
a previous problem, and he recommended I take the shielding off. He was
concerned about flash over - although I had about 400 hours on the coils with
shields with no problems. He also said that shielding modified the E-field
around the coils and could reshape the fields.

I think he has something there. I dutifully removed my nice shields, and
things started going down hill rapidly. The system started missing in flight.
To make a long story short, I shotgunned the system, replacing both coils,
spark plug wires and plugs, which fixed the problem. (He also suggested I send
the brain box if for a look see - again, excellent turn around. One day
service and N/C on the brain box.) I don't know if the shields had
"conditioned" the coils, creating a soft spot that burned through the coils as
the fields readjusted when I took the shields off. Unfortunately, the RFI is
worse now that the shields are off - so I have more work to do. (Might try
some series resistance in the primary...)


Hope this helps,

Mike Palmer
Excellence in Ergonomics