Experimental ignitions systems choice
- Thread starter Olibuilt
- Start date
B
Barnstormer
Keep in mind that if you are running a lithium battery such as EarthX it will go into a protective circuit mode to keep it from becoming fully discharged. Even though it’s not stone dead it is for our purposes so won’t supply power to anything. Just carry a jump pack and you won’t have any problems. Even with one EarthX and a jump pack you would still need to carry at least two more EarthX batteries to equal the weight of one Odyssey.
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cubdriver2
FRIEND
upstate NY
My EarthX has gone dead a few times when the gremlins left the master on for a week. I just hand prop and it charges back up
Glenn
Glenn
Steve Pierce
BENEFACTOR
Graham, TX
Generator is self exciting, alternator is not so it will need battery voltage to be able to start charging.
cubdriver2
FRIEND
upstate NY
Steve Pierce
BENEFACTOR
Graham, TX
That is actually a Dynamo, a little different than a conventional alternator. The reason I mentioned it is about 20 years ago I had a customer who left his master on in his Bonanza. I jumped started him and when he got to his destination he had to lower the gear by hand. I had to fly out with another battery. Having done the same thing with my generator equipped Clipper after coming home in the dark using the landing light only to not have enough juice to turn the starter the next morning it always charged when hand propped. A little research and I discovered why the alternator did not charge like the alternator. Lesson learned. 
fobjob
MEMBER
Salt Lake City, Utah
Sometimes alternators will self-start on a dead battery, though it may take a few minutes, depending on how much residual magnetism is left in the rotor. I see no reason why you couldn't add a tiny magnet to the alternator, say, enough to generate one amp or so without any field current applied....securing the magnet to a rotor would be the tough part. Easier and safer to carry a jump starter battery, all the field needs is two amps for a few seconds.
mike mcs repair
Registered User
chugiak AK
Hmmmmm. Interesting with so much change in starters going to permanent magnets you would think.... hmmm have not been inside an alternator in decades.
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skywagon8a
MEMBER
SE Mass MA6
I would think that it would depend on whether or not there is a master battery solenoid in the circuit. If there is no solenoid there may be enough residual power left in the battery to start the alternator. If there is a solenoid then there may not be enough power to close the contactor so that the alternator will be excited.
Cub Builder
MEMBER
North Central AR
Absolutely right. But, if one installs a simple momentary emergency bypass switch to bypass the master relay, then you should have enough residual voltage to excite the alternator unless the battery is absolutely stone dead. Once the alternator starts charging and the voltage comes up, the master relay will latch closed. With an EarthX, and an alternator, you have to have a jump battery to turn the EarthX battery back on. With an EarthX and dynamo type alternator, you only need to bypass the master relay long enough for the voltage to come up which will turn the battery back on and latch the master relay closed. Dynamos usually don't charge much below roughly 1500 rpm, much like the old generators.
-Cub Builder
skywagon8a
MEMBER
SE Mass MA6
Agreed, but how many systems are planned to be operated with a dead battery?
My recently deceased engine had dual Pmags. My next one will arrive with dual impulse Slicks. I'm not sure whether the Pmags will get a replay. If I go back to electronic ignition I'm favoring Light Speed. Simple and effective. The big question will be whether I go electronic. I've talked to several good engine guys in the past few days. The range of opinions about ignitions varies more than anything engine related I know of.
Steve Pierce
BENEFACTOR
Graham, TX
Been maintaining quite a few Carbon Cubs with the Lightspeed system and have visited with Claus a little. I had an FX2 that had a crank sensor go bad. He was pretty short with me until he relized I had done my homework and troubleshoot it to the sensor which he had never had one fail. Help a guy Saturday who had one coil not firing and figured it had to be the sensor from his troubleshooting. He didn't realize there are 2 pickups in each sensor. i figured that out by not taking the backlash out of the crank the last time I double checked myself and called it good. The flywheel dug into it and exposed the sensors embedded in the unit. Turned out he had a hair of solder hanging between two pins on his harness. Easy fix.
I have learned that the Lightspeed ignition system will fire a lean mixture, don't lean till rough and then enrichen. Go by temps and fuel flow to power. Also the system will run down to about 6.5 volts and then run another 30 minutes on the small Powersafe batteries that Cub Crafters installs in the back up system that you are suppose to replsce every year.
I have learned that the Lightspeed ignition system will fire a lean mixture, don't lean till rough and then enrichen. Go by temps and fuel flow to power. Also the system will run down to about 6.5 volts and then run another 30 minutes on the small Powersafe batteries that Cub Crafters installs in the back up system that you are suppose to replsce every year.
Gordon Misch
MEMBER
Toledo, Wa (KTDO)
Could you please elaborate on that some? Thanks.
hotrod180
FRIEND
Port Townsend, WA
Try asking those engine guys about running mogas.
I've ran 87 octane unleaded ethanol-free mogas for years,
generally mixed with 20-25% 100LL,
and have never had any trouble with it.
But I've heard a number of GA mechanics and engine rebuilder specialists condemn it's use--
usually with very little real (aka verifiable!) reason.
Oh yeah, ask them about lean of peak ops too.
Or semi-synthetic vs regular oil -- or even multi-grade vs regular.
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CamTom12
Registered User
Huntsville, AL
Definitely another option, but not one I’d go with or recommend.
I really like the fact that an electronic ignition will advance at part throttle. Fixed timing is incredibly inefficient for anything other than WOT. And I think a hotter spark in all conditions is good for a complete burn, which is another benefit of more modern ignition systems.
Unless all you ever do is fly WOT 100% of the time. If that’s the case then auto-plugs / wires on mags might do fine.
DJ
MEMBER
Bolivia
In my experience, Slick mags are still having problems with timing drift, as of one year ago. The quality of the parts seems suspect too. To be fair these were not brand new. They were a QAA rebuild with all "genuine" parts. They both drifted 7 degrees in the first 50 hours. If Bendix mags fit my lowered mount I would have them. Been there, tried that but ended up with Slicks.
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Attachments
CenterHillAg
PATRON
Texas Coast
What sort of mount are you running, one of the lowered mounts like Javron makes? I read this a while back and forgot to ask, poked my head in a Super Cub cowling today and the Bendix mags looked tight in there as is. I could see where they wouldn’t fit on a lowered mount with different tubing geometry.
DJ
MEMBER
Bolivia
As far as I know it's a one-off mount by Dan Dufault. I think it might be lowered 1 inch, not 2 inches like Jay was doing.
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