[kevinsky18]

I'm looking at the Light Speed Plasma Electronic ignition for my IO-360-M engine with 9.2:! compression pistons.

Thoughts on Plasma II vs III and direct crank verse Hall effect?

Any thoughts on Dual verses single Electronic Ignition? In the event of an alternator failure in a dual ignition system how long will a battery keep the engine running?

 

[walter]

If you don't have a vacuum pump, why not install a backup alternator.
Then your worries are a bit less. Primary alt, secondary alt, then battery.
Unless your battery falls out of the plane you should be good with almost
any choice of EI. You can even make that more robust with dual P-mags. Although
lately there seems to be some aversion to the P-mags due to their recent
introduction and not insignificant problems, which I believe (hope) they will
fix in due time. Just thinking outloud.

 

[Captain Avgas]

Thoughts on Plasma II vs III and direct crank verse Hall effect?

Any thoughts on Dual verses single Electronic Ignition? In the event of an alternator failure in a dual ignition system how long will a battery keep the engine running?

The crank sensor is slightly more reliable than the Hall Effect but has a longer installation time.

The Plasma III has a longer duration spark and is therefore more efficient at igniting the fuel mix. This can be particularly valuable if running Lean of Peak when the mix is harder to ignite. On the down side the longer spark erodes the spark plugs faster and puts more stresses on the high tension wires and coils. Therefore the mean time between failure is greater on the Plasma II than the Plasma III.

The time that a battery will keep a dual system running depends on the amp/hour capacity of the battery you choose.

Personally I'm opting for a Lightspeed Plasma II on one side and a magneto on the other side (and going with a crank sensor). That's the most conservative option at this particular stage and I opted for that because I intend long flights over water.

If I was opting for dual Lightspeeds I'd certainly want a back-up alternator on the accessory case. That's the only way you can ensure that the engine will keep running until all the fuel is used up.

 

[Walt]

Single vs dual LSI

The crank sensor is slightly more reliable than the Hall Effect but has a longer installation time.


Personally I'm opting for a Lightspeed Plasma II on one side and a magneto on the other side (and going with a crank sensor). That's the most conservative option at this particular stage and I opted for that because I intend long flights over water.

If I was opting for dual Lightspeeds I'd certainly want a back-up alternator on the accessory case. That's the only way you can ensure that the engine will keep running until all the fuel is used up.

I agree with the above, especially until the rest the electrical system have proven itself. I started out the same as Mr Avgas but a year later pulled the mag and installed the second LSI III (first was a II so now I have a II and a III). I definately noticed an improvement in smoothness and can now run LOP (I have a carb) with no problem which I do regularly. I also run a back up vacuum pad gen from B&C. A little over 2 yrs flying and just about to hit 600 hrs with zero problems (about 200 hrs with the dual LSI). I switched from the "Hall effect" to the crank sensor as well for reliability reasons (no moving parts now) when I installed the 2nd system.

 

[chaskuss]

snipped
I switched from the "Hall effect" to the crank sensor as well for reliability reasons (no moving parts now) when I installed the 2nd system.

Walt,
I am facinated by your ability to run lean of peak with a carb. Could you please give us some more info on your experiences in this area?
Charlie Kuss

 

[Walt]

It's really easy, I just keep leaning until the richest (coldest egt) is about 10deg LOP and the hottest is about 50deg LOP. EGT's get within about 50 degrees of each other (they actually get closer as I go on the lean side). With the dual EI the engine does not get rough, with the single EI it would start to get rough anything past peak but with the dual there is no roughness at all. I can actually keep leaning and feel the power falling off but it's still smooth. For ref my normal power setting is around 2350/20" which gets me around 6.5gph at about 50-55% power I figure (close enough for me). Average speed at this setting is around 135 Knots. Anything below 65% I always run at peak or LOP these days. Over 75% I still run ROP but this only during take off and climp, once I'm at altitude I pull the power and the mixture back.

 

[Captain Avgas]

I started out the same as Mr Avgas but a year later pulled the mag and installed the second LSI III (first was a II so now I have a II and a III). I definately noticed an improvement in smoothness and can now run LOP .

Hi Walt, of course it might be possible that the improvement you have experienced in smoothness arises from the installation of the Plasma III with the longer duration spark (rather than the fact that you have dual units now).

What happens when you switch off the Plasma II in flight....do you notice any difference or is it just along for the ride.

 

[Walt]

No it's not like the mag which was along for the ride, now if I switch off either LS I notice the difference immediately both in smoothness and higher EGT's.

 

[Captain Avgas]

No it's not like the mag which was along for the ride, now if I switch off either LS I notice the difference immediately both in smoothness and higher EGT's.

Walt, you're a great source of information on this topic. Next question. When you're running LOP (or ROP) and you switch off one EI, can you notice any difference in performance between the single Plasma II and the single Plasma III. You're the only person I know with one of each to be able to compare.

Cheers Bob

 

[mburch]

The Plasma III has a longer duration spark and is therefore more efficient at igniting the fuel mix. This can be particularly valuable if running Lean of Peak when the mix is harder to ignite. On the down side the longer spark erodes the spark plugs faster and puts more stresses on the high tension wires and coils. Therefore the mean time between failure is greater on the Plasma II than the Plasma III.

That's very interesting - I hadn't heard that before. I went with a single Plasma III instead of a II on my engine, solely based on the idea of "well, it's not that much more expensive and everybody says it's better, so why not?" I guess I'll have to keep an eye on it.

Walt - Let us know which one breaks first, Plasma II or III...

mcb

 

[Walt]

Comparison LSI II and III

Walt, you're a great source of information on this topic. Next question. When you're running LOP (or ROP) and you switch off one EI, can you notice any difference in performance between the single Plasma II and the single Plasma III. You're the only person I know with one of each to be able to compare.

Cheers Bob

At the moment I don't think I can fairly compare the two because I am currently running the standard Denso plugs on the LSI III but switched over to IK27 Iridium in the II. The Iridium seems to run better than the strandard and next time I have my cowl off (probably this week before my trip to S&F) I am going to put Iridiums in the bottom for the III system as well. Right now I'd almost have to say I'd give the II the nod vs the III on the comparison but we'll see what happens after the plug change. I have about 400hrs on the first set of Iridiums and they still look good but I'm going to put 8 new plugs in this time around just for the heck of it (I'm kinda anal about my maintenance). I found the Iridium plugs for about $10 a pop and I believe they could easily last 3 times as long as the standard plus they run better

 

[Captain Avgas]

At the moment I don't think I can fairly compare the two because I am currently running the standard Denso plugs on the LSI III but switched over to IK27 Iridium in the II. The Iridium seems to run better than the strandard and next time I have my cowl off (probably this week before my trip to S&F) I am going to put Iridiums in the bottom for the III system as well. Right now I'd almost have to say I'd give the II the nod vs the III on the comparison but we'll see what happens after the plug change. I have about 400hrs on the first set of Iridiums and they still look good but I'm going to put 8 new plugs in this time around just for the heck of it (I'm kinda anal about my maintenance). I found the Iridium plugs for about $10 a pop and I believe they could easily last 3 times as long as the standard plus they run better

Walt, yes you are correct...it's probably not a fair comparison if you are using different plugs. The iridiums are considerably more efficient than standard plugs...less shielding, less quenching.

I'll keep monitoring this thread. If you would report back when you change to all iridiums that would be great.

It would be interesting to draw a comparison of the II and III both ROP and LOP. You'd intuitively think that the IIIs would theoretically perform better LOP...but this is a great chance to find out the facts. In the end there may be no discernable difference

By the way where did you get iridiums for $10 (normally +$60). That's the best bargain I've ever heard. They're not off the back of a truck are they ?

Cheers Bob

 

[Captain Avgas]

That's very interesting - I hadn't heard that before. I went with a single Plasma III instead of a II on my engine, solely based on the idea of "well, it's not that much more expensive and everybody says it's better, so why not?" I guess I'll have to keep an eye on it.
mcb

Yes Matt, it's a fact. But you need to put this in perspective...both the II and the III are considerably more reliable than a magneto (as long as you can keep a flow of electrons running to them).

With electronic ignition, failures, although not common, invariably turn up very early when they do occur. The longer the device runs the less likelihood of a failure. If you get to 100 hours you should be good for 1000. With magnetos it's the other way around...the chances of a failure when new are very small but increase proportionally with time. From +500 hours the chances of failure with a mag are very high.

 

[kevinsky18]

Well I've decided to go with Dual LSP III-Direct Crank. I'll be ordering it with the engine so Aerosport will be handling the install on the engine.

Thanks again for everyone's feedback and assistance in helping make another tough choice.

 

[fodrv7]

High Compression Pistons

Kevin,
Being a Kamloops boy I imagine you are going to buy an engine from Bart.
I did and I am delighted with it.
I did get High Compression Pistons, but I am not so sure it was a good idea.

No one seems to have checked any Lycoming/propeller combinations for harmonics with engines running high compression pistons.
The Plasma III I have fitted includes Spark Advance and I do not know if the Mapping for the spark advance is compatible with high compression pistons and what is it's related effect on the dreaded Red Box. I would like to know if anyone can enlighten me.

Bob,
Since we flew the other day my Plasma Hall effect sensor pulg came loose, disabling the ignition. This happenned at 50hrs and now at 150hrs.
The screws retaining the plug are now loctited and lockwired.

Pete.

 

[Walt]

By the way where did you get iridiums for $10 (normally +$60). That's the best bargain I've ever heard. They're not off the back of a truck are they ?

Cheers Bob

Bob, The Automotive IK27 is cheap compared to the Aviation Iridium, LTB motorsports has them for $10.95!

 

[Captain Avgas]

Are you there Walt

At the moment I don't think I can fairly compare the two because I am currently running the standard Denso plugs on the LSI III but switched over to IK27 Iridium in the II. The Iridium seems to run better than the strandard and next time I have my cowl off (probably this week before my trip to S&F) I am going to put Iridiums in the bottom for the III system as well. Right now I'd almost have to say I'd give the II the nod vs the III on the comparison but we'll see what happens after the plug change. I have about 400hrs on the first set of Iridiums and they still look good but I'm going to put 8 new plugs in this time around just for the heck of it (I'm kinda anal about my maintenance). I found the Iridium plugs for about $10 a pop and I believe they could easily last 3 times as long as the standard plus they run better

Hi Walt, were you able to compare the LSI 11 and III on your trip to S&F. Any report.

 

[Walter Atkinson]

Gentlemen:

A couple of thoughts on the subject at hand:

1) to run LOP smoothly, you need three things; a healthy ignition system, balanced F:A ratios, and no induction leaks.

2) Quite a few folks are combining high compression ratios with electronic ignitions. This is frequently done without regard to the resulting peak internal cylinder pressures which can get quite high, quite quickly. We've looked at these combinations on a properly instrumented test cell and are not happy with what we see. Be advised that, unless you have hard data on the timing changes combined with high CR, you are taking risks of creating serious problems. So far, none of the EI system manufacturers seem to have any of this data. I find that worrisome.

Be forewarned.

 

[RVadmirer]

Another Source: Sparkplugs.com

Iridium plug, 14mm thread, 19mm reach, 16mm(5/8") hex, gasket seat, ISO height, 0.4mm iridium center electrode, tapered cut U-groove ground, resistor, .032" gap
Exact Match:



Spark Plugs

Denso Iridium plug 5312 IK27 $11.99

 

[Walt]

I did a little comparison..

Hi Walt, were you able to compare the LSI 11 and III on your trip to S&F. Any report.

But not much as the wife really prefers I not "fiddle" with things to much while we're flying

I will continue to test when I have more time and it's just me flying but the little bit of check out I did after installing all iridiums still show the top system which is the LSII to make the engine run a little smoother than with just the lower LSIII running. Perhaps Klaus knows something we don't as he also recommends when installing a single system that it should go in the top.

Great trip to SnF with the wife and as usual the aircraft performed flawlessly even loaded to the gills with everything but the kitchen sink

 

[AlexPeterson]

Gentlemen:

SNIP

2) Quite a few folks are combining high compression ratios with electronic ignitions. This is frequently done without regard to the resulting peak internal cylinder pressures which can get quite high, quite quickly. We've looked at these combinations on a properly instrumented test cell and are not happy with what we see. Be advised that, unless you have hard data on the timing changes combined with high CR, you are taking risks of creating serious problems. So far, none of the EI system manufacturers seem to have any of this data. I find that worrisome.

Be forewarned.

Walter, the combustion charge doesn't really know that the engine is high compression unless the MAP is set high, does it? For example, a 9.0:1 engine with a MAP of 23 might be the same combustion situation as a 8.5:1 engine at 24, for example. Most of the EI's, I believe, do not advance much beyond baseline at MAP's in the 25" and higher range. I may be wrong on that, I don't recall exactly. Do you know what the timing schedules are for MAP vs RPM for the various ignitions? Lots of variables...

 

[mgomez]

Dumb question

Is it possible to have two Plasmas, one with the Hall effect sensor and one with the crankshaft sensor?

 

[Captain Avgas]

I will continue to test when I have more time and it's just me flying but the little bit of check out I did after installing all iridiums still show the top system which is the LSII to make the engine run a little smoother than with just the lower LSIII running.

Walt, thanks for that info. VERY interesting. I appreciate that you went to the trouble of doing the test for me.

Regards Bob

 

[dan]

Is it possible to have two Plasmas, one with the Hall effect sensor and one with the crankshaft sensor?

Yup. Some would argue that's the "best" way to go in terms of dual EI redundancy.

 

[mgomez]

Yup. Some would argue that's the "best" way to go in terms of dual EI redundancy.

That was my thinking, too, but the engine vendors all seem to offer "dual crankshaft" or "dual Hall effect" so I was afraid there was a reason it couldn't be done.

Thanks, Dan.

Martin

 

[glider4]

Crank Sensor and Hall Effect with Lightspeed EI

I have an Aerosport Power IO-360B2B with dual Lightspeed Plasma II being built up right now. Bart recommended going a with one Hall Effect and one Crank sensor to avoid a single point failure situation. I haven't received the modified quote yet but it should be pretty close to a wash in terms of cost.
Al Thomas
N880AT
RV-8A (finishing kit)

 

[Walt]

I love my dual LSI

but I switched from the hall effect to dual crank pick up because I could not get the hall effect to stop seeping oil. I initially was going to keep the hall effect and put the other one on the crank for the single point failure mentioned but decided in the end no moving parts, no oil seals, no bearings etc would be the winner in the long term for reliability. I never did figure out why the hall effect modules leaked but I now suspect it may have had something to do with running the synthetic oils. Other than the leaks I have had zero problems with the LSI's. Now 600 hrs total, 300 with one LS and one mag and 300 with dual LS. Definate improvement noted with the dual LS I might add.

 

[cjensen]

Anything new with this lately? I've been researching EI's today, and I like the LSI ignitions. I've looked at all the available EI's, and it seems people are most happy with LSI.

Just looking for an update on it...