Lightspeed Plasma III problem - Page 4

RVadmirer · #31 06-21-2009, 06:39 PM

Yes William, that's rather obvious. But the heat after shutdown can be amazing. Can't hardly touch my cowls directly over the cylinders for 5-10 minutes and that is where the coils are sitting, hence my concern. I run a fan through them at home to enhance the cool down and extend the coil life a bit.......
Seems like there are better places to mount the coils?

David_Nelson · #32 06-21-2009, 08:39 PM

Quote:

Originally Posted by RVadmirer

Speaking of "heat soaked coils", has anyone mounted them somehwhere cooler than on top of the engine in probably the hottest place possible, as suggested by the manufacturer? (!)
Has this resulted in a better life span?

Apparently, the engine mount can also be used as documented on LSE's www site. Check out the 2nd picture from the bottom:

http://www.lightspeedengineering.com...ionInstall.htm

MSFT-1 · #33 06-21-2009, 08:51 PM

I started this thread so I thought some people might be interested to know what I found.

In the six cylinder LSE design there are three coils (one for cyl 1 and 2, a second for 3 and 4, and a third for 5 and 6). I swapped two of the coils and the problem moved along with the suspected bad coil.

In this particular case, it was the coil for cylinders 3 and 4 that failed.

About $80 from LSE to replace it. I ordered two.

Airplane is 18 months old and has just under 250 hours on it.

Pilottonny · #34 06-22-2009, 12:05 AM

I have dual Plasma II and mounted 2 coils on top of the engine (cool while engine is running, but wet if flying in rain!) and 2 on the engine mount (hot while engine is running but dry if flying in rain!). I am not flying yet, so I have no idea what the temperatures are in those area's, but I guess with the coils in two different locations, I should have the most reliable set up.

BTW, has anybody had any problems when the connections of the coils get wet in the rain?

Regards, Tonny.

Kahuna · #35 06-20-2011, 10:13 AM

I have had several coils fail. According to Klaus, its the weakest point in the system. Further, he is theorizing that the coils are failing due to the increased resistance caused by a widening gap noticed mostly when using NGK plugs. THis was news to me today when discussing it with him. He recommended I go to the Densso or better the Iridium plugs for a reduced wear gap, and see if I continue to see failures. I seem to loose one about one every year or couple hundred hours.
My symptoms are easy to spot and I only loose one side of a coil. First I notice my engine monitor giving all kinds of whacky readings on all sensors intermitently. A few hours later, I loose one side of a coil.

fl-mike · #36 06-20-2011, 10:22 AM

Quote:

Originally Posted by Kahuna

I.... According to Klaus, its the weakest point in the system. Further, his is theorizing that the coils are failing due to the increased resistance caused by a widening gap noticed mostly when using NGK plugs...

I would agree with Klaus. Those coils should be pretty bulletproof, unless they start arcing internally and breakdown the wire insulation. At some point the electrons would rather jump the insulation than jump that increasing spark plug gap.

Walt · #37 06-20-2011, 10:25 AM

Klaus may be right

I've been running the LSII for almost 1200 hrs and the LSIII for about 700 hrs and have had zero coil failures. I've also been running the Denso IK27 since the beginning.

N8RV · #38 06-20-2011, 01:19 PM

Beginning a couple of weeks ago, I noticed that my #1 EGT was running a bit higher than normal. It's always run hotter than the others by a large margin (100-125 degrees), and I was planning to swap probes and see if the high temp moved with the probe. I also noted that, in order to keep the #1 EGT below 1400 degrees, I had to run the fuel flow at 9gph or higher at my usual power settings. Hmmm ...

I flew a short hop on Friday and all was well, except for the anomaly noted above. On Saturday, I offered a ride to a guy and strapped him in. We taxied to the end of the runway and I did my run-up. Left mag, OK. LSE, not so much. Sputtering and big rpm drop. We taxied back to the hangar to fly another day.

I un-cowled and checked the wiring. All looked fine. Pulled the plugs, expecting to find some lead deposits, but all looked clean with just some carbon buildup.

The auto plugs (standard ones supplied with the LSE unit) measured at the large end of the gap recommendation (.034"). These plugs have 145 hours on them.

I wrote to Klaus today and got back a response as has been mentioned here and elsewhere -- at 145 hours on the stock plugs, a coil might have gone belly-up. So, I just ordered new plugs and now I'll have to figure out which coil went bad. A phone call to Klaus got me started in tracking down the gremlin.

Who knew that the plugs had to be replaced so often?? I've owned lots of cars over the years, and can't think of a single one that I've EVER replaced the spark plugs in ...

Ron Lee · #39 06-20-2011, 02:28 PM

Have you seen this chart Don?

http://www.lightspeedengineering.com...oubleshoot.htm

N8RV · #40 06-20-2011, 05:01 PM

Quote:

Originally Posted by Ron Lee

Have you seen this chart Don?

http://www.lightspeedengineering.com...oubleshoot.htm

Yes, Ron, I did. And when I saw something about using an automotive timing light and measuring resistance through the coils, I knew that I was out of my league. I built the plane. I hooked up the engine. I ran the wires from the panel to the engine probes. But I know nothing about engines and am only slowly learning as I go. As Harry Callihan famously said, "A man's gotta know his limitations."

Sometimes taking a short cut directly to the source saves a lot of time and frustration, and a phone call to Klaus seems to have gotten me off to a start.

Thanks for pointing out the flow chart.