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Electronic ignition - huge benefits claimed

These people - Electroair seem to have 4-cylinder solutions and apparently they will soon have 6-cyl versions.

I am not too impressed with the electronics enclosures which don't look like they are hermetically sealed...

Does anyone know anything about them?

Administrator
Shoreham EGKA, United Kingdom

Quite a few people on the Cessna Pilot Assocation Forum have installed this kit in their 172s. Reports are rather favorable.

Note that they don't suppor the dual magneto setups (TB20, right?).

I installed the EIS-41000 system on my 172M/150hp, and have operated about 55 hours now, with almost all of it being a vacation trip from florida to California and back over high terrain and July temps. It's a work in progress and there are lots of little issues to be worked out by the STC holder and each operator. TransPac is a large flight school in Arizona, and they have more experience than anyone else. I can tell you that at a hundred pounds under GW, we were able to depart Bryce Canyon in the afternoon and climb in the holding pattern to the MEA of 13000 ft for the airway with 4 of us on board. That's pretty good for 150 hp and would not have been possible with 2 mags. Also, at this weight, max rpm at 12000ft produces 122kts true at 6.9 gph. The UREM-37BY-HE plugs are not quite available from tempest yet, but should be any day. That should yield another small improvement. Post with specific questions.

From the FAQ:

18 If my engine has a dual magneto, how do I adapt my engine to use the EIS? We use a split ring collar on the crank shaft for the electronic ignition timing pick-up. You can keep the dual mag install with one side capped off, or there are some single magnetos that will adapt to the dual mag hole.

I'm just having my O-360-A1AD re-done (with the now unsupported dual bendix mag), it would be great to install one of these, but I don't see any mention of EASA certification. If they do manage anything close to a 10% fuel saving for the same power output (with appropriate leaning of course) then the cost of an STC should pay for itself pretty quickly. I wonder if any of the larger european design organisations would take this on?

Maybe I'll email electroair and ask if they have any plans for EASA certification.

EGEO

Note that they don't suppor the dual magneto setups (TB20, right?).

Yes; the -C4D5D engine is single shaft dual mag, series 3000 Bendix.

Am I right in that these ignition systems seem to do only half the plugs. I spoke to Lyco about theirs and they were saying they do only half the plugs too.

But surely that means the electronic ignition is able to only advance the spark timing, not retard it (as may be useful for a lean mixture and low revs).

with the now unsupported dual bendix mag

The Series 3000 mags were indeed dropped by TCM and for about a year there was a lot of uncertainty.

Most of the parts were always PMAd but some (e.g. the impulse coupling spring) were not, and once they ran out... during this time I had a mag (I keep a spare on the shelf) overhauled by a certain EASA145 UK firm which claimed to have the springs. They then refused to supply a copy of the work pack and got quite nasty about it, so I drew the obvious conclusion and re-overhauled that mag in the USA - £800 wasted.

But a year or so ago Hartzell bought all the tools and it's back in production.

I use this firm for accessory overhauls - they are excellent and have a super reputation among engine rebuilders.

Anyway that's digressing... I thought most single shaft dual mag engines had a spare mag drive. Mine certainly has; it has a cover on it. I was planning to install a little backup alternator in there one day.

If they do manage anything close to a 10% fuel saving for the same power output (with appropriate leaning of course) then the cost of an STC should pay for itself pretty quickly

I would be really amazed if they achieved 10% relative to a correctly operated engine (peak EGT or LOP with GAMIs). How on earth would that be achieved?

Also I will never go back to Champion plugs, if such were needed.

Administrator
Shoreham EGKA, United Kingdom

Peter - Seems to me the standard fixed timing setting will be spec'd for max over-square operation. That same low rpm/high MP regime is typically where you get highest engine efficiency... so you're right, variable timing likely won't affect peak engine efficiency. However, high airframe efficiency is not achieved under the same conditions - that requires high altitude and for a non-turbo, lower MP.

The potential increase in combined engine/airframe efficiency would be when running at lower MP, high rpm, now with more advanced timing. Light Speed has shown there's some scope for a little lower fuel consumption per mile in that high altitude regime. There would never be a need to retard the timing relative to standard.

I think the overall issue is not necessarily highest engine SFC but highest combined engine and airframe efficiency.

In the last US AOPA mag there is an article (an "advertorial" I guess) about a firm called Light Speed Engineering which claims a 16% fuel flow reduction for the same power.

The figures they give are (IO360)

0.60lb/HP (per hr) full-rich
0.54lb/HP (per hr) leaned at max power
0.43lb/HP (per hr) leaned at 60% power
0.36lb/HP (per hr) with electronic ignition

16% is a massive gain in the SFC.

This product also has its own power so - unlike with the Thielerts - the engine will keep running if the aircraft electrics are dead.

Administrator
Shoreham EGKA, United Kingdom

I don't know about the quantum of gains or the issues re power but electronic ignition must be superior from an efficiency and smoothness perspective. We fitted it in an old classic car (12hp) replacing points and it was transformational.

EGTK Oxford

My set-up is a Lightspeed Plasma 3 ignition on the RH side, plus a standard Slik impulse mag.

That gives a powerful, long duration spark over a large gap with ignition advance controlled by RPM and MP.

I think that I'm easily 10% better than a two magneto set-up. Typically less than 7 USG/hour running LOP, 62% power at 9-10,000' (IO-360 180HP). That is below 0.4 lb/hp.hr

At higher altitudes combustion is slower and a magneto system will not give complete combustion inside the cylinder. It will also keep you running smoothly at mixtures too lean for a magneto, even without GAMI type injector tuning.

I've not seen the latest Lightspeed, but I guess it is similar to the P-Mag offering that can generate it's own energising power once the engine is running. This make a dual electronic set-up more easily certifiable as you keep running even with complete electrical failure.

Another advantage is reliable starting, hot or cold, with an injected engine.

Klaus at LSE has achieved some amazing efficiency levels on his modified Long-eze.

KHWD- Hayward California; EGTN Enstone Oxfordshire, United States

0.60lb/HP (per hr) full-rich
0.54lb/HP (per hr) leaned at max power
0.43lb/HP (per hr) leaned at 60% power
0.36lb/HP (per hr) with electronic ignition

Is that 0.36 leaned at 60% and with electronic, or is it full rich with electronic?

[edited for text formatting]

ESSB, Stockholm Bromma

Aviation Consumer have looked at FADEC several times. My recollection is that they have not been able to substantiate the efficiency claims generally made by the manufacturers.

It must depend on the basis for comparison. Even if electronic ignition does not improve sfc much for a power setting where a traditional engine is doing well, it should make high efficiency achievable over a wider range of conditions by varying ignition timing. As I understand it, one of the problems of low-rpm operations is that due to fixed ignition timing the beginning of the combustion cycle (when normally leaned) takes places with the piston at or before top dead center, which creates extra high loads on rods and crankshaft. With a delayed (variable) ignition, loads could be reduced so that the efficiency gains of a lower rpm could be utilized without harming the engine.

huv
EKRK, Denmark
221 Posts
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