LSE Coil. Source and application

[elippse]

[quote=Kahuna;431425]One side of one LSE coil died this weekend. Not a failure mode I would have expected.
QUOTE]

You're right, that is an unusual failure mode. The primary and secondary coils are isolated from each other. To say that only half of the coil had failed to be true then I would suspect that the secondary winding which feeds the plugs must have shorted internally, shorted to the primary, shorted to ground on one end, or it has an open connection on one end, in which case it probably wouldn't be able to fire the other plug since they are in series connection; what goes through one goes through the other. So you've run enough continuity tests to verify that it is in the coil and not an open plug lead or a lead that is breaking down and arcing to ground?

[Ron Lee]

I bought a spare from Klaus.

[gasman]

[quote=elippse;431580]

Originally Posted by Kahuna

One side of one LSE coil died this weekend. Not a failure mode I would have expected.
QUOTE]

You're right, that is an unusual failure mode. The primary and secondary coils are isolated from each other. To say that only half of the coil had failed to be true then I would suspect that the secondary winding which feeds the plugs must have shorted internally, shorted to the primary, shorted to ground on one end, or it has an open connection on one end, in which case it probably wouldn't be able to fire the other plug since they are in series connection; what goes through one goes through the other. So you've run enough continuity tests to verify that it is in the coil and not an open plug lead or a lead that is breaking down and arcing to ground?

Good catch!! It is a lost spark system. One coil fires two plugs at the same time. You should have two dead cyl's if the coil is bad.

[rvmills]

Late to the thread (been on the road), but Kahuna, I also had a half-coil failure on my S-6. Initial indication was a bad "mag" drop. Did all the troubleshooting process recommended on the LSE website, and saw only one cylinder's EGT was abby-normal on the LSE only (mag off). Checked for spark on all leads, and sure enough only 1 of 6 cyls had no spark. Called Klaus and asked if only half a coil could fail, and he said yep (no surprise in the response, so though it may be an odd failure mode...I concur with you on that...didn't think it possible till I talked to K, sounds like it's not all that farfetched...as we've found out).

Just passing it along to save others some troubleshooting head scratching. If you show just one bad cylinder, it could be a half-bad firing coil.

I bought a new coil from LSE, but I've since swapped to an Electroair, and sold most of the remnants, but may have a coil in my stash. I'll look, and let ya know.

Don't know about the firing coils, but FWIW, I believe the trigger coils on my ol' Plasma I were Honda, if that helps you sleuth out a source for the firing coils.

Cheers,
Bob

[Mike S]

Originally Posted by rvmills

was abby-normal on the LSE ------

Cheers,
Bob

Thanks, I gore

[az_gila]

Originally Posted by rvmills

.....
I bought a new coil from LSE, but I've since swapped to an Electroair, ....Cheers,
Bob

...to be less popular than the LSE, why did you change?

gil A

[rvmills]

Originally Posted by Mike S

Thanks, I gore

"What Hump?"

And yes Mike, we're dating ourselves...had a HS date to that movie...and no her name was not Abby!

Who can name it? (Yes, way OT, but...)

Originally Posted by az_gila

Snip>...since ElectroAir seems...to be less popular than the LSE, why did you change?

gil A

Gil, it was a tough decision on some levels and an easy one on others. (And apologies for going a bit OT and long here...sorry Kahuna!)

On the technical side, both systems are excellent. I had great service with my LSE PI, until the brain box failed (after many years...it was in the plane when I bought it). The failure was intermittant enough that it prevented Klaus from determining the cause (the first time I sent it in, it came back as being OK, and the second time LSE could replicate it, but could not trace it, 'cause it went away when the box warmed up or was pressed on...yep, weird...and sort of like what I saw in the field...though I never pushed on it, bad mag drops just came and went).

I had done months of troubleshooting and component replacing, and when the box came back bad on the second go-'round, I was looking at a new brain box and crank sensor, whether I went the LSE PIII or the ElectroAir route. Both options required pulling my prop (for the crank sensor...old one had to come off anyway, and no Hall Effect sensor for a six cyl motor). ElectroAir represented a full system change (more parts to swap), but after discussing the EA system with a highly respected VAF member and hearing of his happiness with multiple installed EA systems (RV-4s and Rockets), and after seeing a Jeff Rose system (precursor to EA) on a local Rocket, I spoke with Mike at EA.

I really, really liked working with Mike, and that was the primary reason. Super folks there, very helfpul with the install and any questions I had.

In comparing the performance of the two systems, again, both are superb, and to be honest, if there is a performance difference between the two, I can't see it. There are differences in how they generate the spark (capacitance vs inductance, from what I understand, though to be honest its a partial understanding), and there appear to be subtle differences in spark dwell and timing (per discussions, not empirically). ElectroAir has the ability to make timing adjustments on the box, and has a provision to show what the timing advance is on a gauge, though I have not used those features yet, so they were not key factors. However, those features got my attention, and I may play with it in the quest for speed, since I've started racing with SARL. The manual was very well laid out, and the install was pretty darn straight forward. The components all look to be very high quality as well, and I like the sturdy mount for the firing coils. It is designed to be firewall mounted, which is where my LSE coils were as well. I know many like to mount the coils on top of the engine for shorter spark plug wire runs, so this may be viewed as a negative, but I really like the EA set-up, and their coils may be OK on top of the block too, I just don't know.

An interesting side note Gil, which hits on the popularity issue you mentioned...in discussions with Mike, I asked why he wasn't advertising more heavily in an attempt to get more market penetration. He told me that his company's time and efforts over the past few years had been geared towards obtaining full certification for their systems (ie, getting auth to put them on type certificated aircraft, Bonanzas were mentioned in the discussion). He's not ignoring the experinmental market, but has focused on the certification process (in my words now) in hopes of capturing the attention of both markets. Mike noted that LSEs are indeed more well known, and speculated that many large experimental engine builders offer them as "OEM" because that is what clients most often ask for. Probably a tough market to crack when a competitor is as well known and respected as LSE. But imagine a product whose producer has done the due diligence and met the rigor to have the product approved for type certificated aircraft. They're not there yet, and I don't know the current status, but it didn't sound like hollow sales pitch talk to me, and it got my attention. Hopefully that won't mean higher prices, because EA wins there too (though that was not a major concern of mine at all, as I had invested some pretty good coin in my earlier LSE troubleshooting efforts).

The last piece is not official in any way of course, and is just me flappin' my gums about how I came to the decison.

And did I mention that Mike and his team are really nice guys!

Cheers,
Bob

[Kahuna]

[quote=gasman;431638]

Originally Posted by elippse

Good catch!! It is a lost spark system. One coil fires two plugs at the same time. You should have two dead cyl's if the coil is bad.

This is not true.
Half of the coil can die and leave ONE cylinder out. Test... swap only the wires on the coil. Dead cylinder moves.
Swap back. Dead cyclinder moves. Continue until your convinced the above statement is not true.

[az_gila]

Originally Posted by rvmills

Gil, it was a tough decision on some levels and an easy one on others. (And apologies for going a bit OT and long here...sorry Kahuna!)
......
Cheers,
Bob

...thank you for the detailed explanation... gil A

[rvmills]

[quote=Kahuna;432423]

Originally Posted by gasman

This is not true.
Half of the coil can die and leave ONE cylinder out. Test... swap only the wires on the coil. Dead cylinder moves.
Swap back. Dead cyclinder moves. Continue until your convinced the above statement is not true.

Concur...exactly what I saw in testing, and the failure mode was confirmed by Klaus. Good news, easy fix...new coil (as you know...and carrying a spare became my MO). Will be out at the hangar today to see if I still have an old spare LSE coil Kahuna.

Cheers,
Bob