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Spark plugs

wireweinie said:
100% agree. I'm just expressing my exasperation with a large chunk of the human race.

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I 100% agree with your exasperation, but I disagree that installing an engine monitor is a waste of ounces.

Just because some folks won’t understand what it says doesn’t mean that installing the thing isn’t a good idea. A good, maintenance-savvy pilot who yearns or efficiency (who we should all strive to be) will make good use of one.

And maybe a guy that wants to do the right thing but doesn’t know any better yet reads a comment about an engine monitor not being worth the weight. Then he skips installing one. Then he loses the opportunity to optimize his engine management and have an excellent cylinder troubleshooting tool.

Just a hypothetical, maybe not worth much.
 
I like Tempest fine-wires. I put them in with a new engine and run them to TBO. Then I do it again. I have many boxes of 1700 and 1900 hr perfectly good plugs. I like them because they are less work and more reliable than massives, and tend to break porcelains less than the Champion fine-wires ... and they are less expensive.. and they are nickel plated so less prone to rust..
 
EGT is a great diagnostic tool for a sick engine. Went to start my O-470R yesterday and barely got it started. It spit, sputtered, backfired, and wouldn't idle. The EGT on the right bank was stone cold. Pulled the cowl and found the crossover tube for induction had come loose causing a massive air leak. Reattached it with a new sleeve and all is well.
 
mike mcs repair said:
and the AD or SB issued number was???

or was it just internet theory ???? I don't follow/pay attention to much internet theory...

not saying i don't appreciate the heads up... it makes sense!!
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Mike, they had tempest come up and give a presentation at the IA seminar in Anchorage about 13 years ago...so the information was being put out and its also called out in the mil spec for plugs. Champion just failed to follow the mil spec because the military is not really running recip engines anymore. Tim
 
I've followed this thread with great interest. Lot's of good information. Like others have noted, interesting that it didn't seem to be more widely known. I'd never heard of it before.

I bought the Tempest plug tester to use during the annual last fall. The plane had been starting good and running well, though seemed like some rough running if I did many closed traffic landings. During the annual, 5 of the 8 Champion fine wire plugs tested red !!!!! I replaced all 8 plugs with Tempest massive plugs. Starts good and runs well. Not rough during stop and goes anymore. Coincidental? I don't know.

We overhauled the engine in 2012. Several years prior to that I had installed 4 Champion fine wire plugs in the lower plug holes. For the overhaul, I bought four more Champion fine wire plugs. The eight plugs were randomly installed (ie didn't put all older plugs in upper or lower, etc). That was about 300 hours ago. Present circumstances don't give me a lot of time to fly.

I used a digital multi-meter to test the ohms on the 8 fine wire plugs I removed. Here are the test results and ohm readings:

Green Installed prior to 2012 1,830 ohms
Green Installed 2012 1,600 "
Green Installed 2012 1,540 "

Red Installed prior to 2012 810,000 ohms (is that even possible ?)
Red Installed prior to 2012 139,600 "
Red Installed prior to 2012 14,800 "
Red Installed 2012 12,880 "
Red Installed 2012 12,500 "

I don't have access to a pressure tester, though will likely hang on to these plugs and test if I get an opportunity.

astjp2, what do you mean by "open circuit"? No current going through them at all? How did the engine run?

Jim
 
The ohm test does not work on the old carbon pile spark plugs. Joe Logie at Champion told me the ohm test is a marketing thing from Tempest. He said if the plug passes a pressure test it is good. I have always used my pressure tester and never had an issue. I believe with so many customers with engine monitors if there was an issue it would have happened already. I use Tempest plugs myself, can't see paying so much more money for a name. I have ohmed plugs with my Fluke meter and seems the results are all over the place. I will continue to use my spark plug pressure tester until it is proved to me a plug can pass that test and fail an ohm test and not work in the engine.
 
I have had 2 plugs in a Colt that caused it to run like **** intermittently, we cleaned, gapped the plugs, they all pressure tested good, I ohm'd them and guess what? Problem went away! It takes about 3 minutes to ohm them, if they fail any of the tests, just replace it.
 
I’ve always had good luck with Tempests in my J3 and 182, so I switched all the plugs in the 985 on my Ag Cat to Tempests the first annual after I bought it. Within 50 hrs plugs were failing all the time, mag check at 1600 rpm would be fine but checking mags at working power settings revealed dead plugs. One of the overhaul shops recommended switching back to Champions, he had better luck with them in round engines. Sure enough that cured the problems right away and that’s all I’ve run in it since then. A buddy that maintains a bunch of radial engines has the same experience, his theory was the Tempests couldn’t handle the cylinder pressures of a supercharged radial running at high power settings for long periods.
 
I took apart a Champion plug that showed "open" with Fluke ohm meter. The resistor was pretty well burned, which is equivalent to a increased gap at the sparking end. At the same time my Bendix mags had their 500 hour check, and there was some tracking. I can't help but wonder if the increased effective gap could have contributed to that.
 
Gordon Misch said:
I took apart a Champion plug that showed "open" with Fluke ohm meter. The resistor was pretty well burned, which is equivalent to a increased gap at the sparking end. At the same time my Bendix mags had their 500 hour check, and there was some tracking. I can't help but wonder if the increased effective gap could have contributed to that.
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aircraft magneto service claims that it hurts the coils.
 
skywagon8a said:
With an all cylinder EGT instrument installed in the airplane, a faulty plug can be found in less time than it takes to read your post without removing the cowl.
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No EGT necessary. Just run it a bit on the bad mag and spit on each exhaust stack,bad plug will be obvious.
 
Steve Pierce said:
Using the rotation sequence Champion and probably Tempest recommends the fine wires should last to TBO and not foul. Massive electrodes normally wear beyond my no go gauge in 500 hours and do seem to foul more. In my opinion it is a pay now or pay later.
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I find that a lot of owners think the massives' are cheaper and in the long run, its all the same
 
Steve Pierce said:
The ohm test does not work on the old carbon pile spark plugs. Joe Logie at Champion told me the ohm test is a marketing thing from Tempest. He said if the plug passes a pressure test it is good. I have always used my pressure tester and never had an issue. I believe with so many customers with engine monitors if there was an issue it would have happened already. I use Tempest plugs myself, can't see paying so much more money for a name. I have ohmed plugs with my Fluke meter and seems the results are all over the place. I will continue to use my spark plug pressure tester until it is proved to me a plug can pass that test and fail an ohm test and not work in the engine.
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Steve, I have had the experience of plugs (Champions) in a Husky that ran a bit rough...still ran, but just wasn't as smooth as desired. Resistances were upwards of 50Kohms on several of the plugs. They all passed testing with pressure tester. I replaced them with Tempests, and the roughness went away. (perhaps of interest, the EGTs had slight variance with the Champions).

In discussion with George Braly of GAMI, they have found a lot of problems with high resistance in plugs that pressure tested okay, but would misfire at altitude. (see https://taturbo.com/frames.html).

It makes sense in the context of Ohm's law....P=EI, I=E/R. As Resistance goes up, the amount of voltage required to generate enough power for the spark to jump the gap of the plug goes up as well. (exactly why the guy you helped had a problem....at low engine rpm, the mags weren't generating enough voltage for the spark to jump the (larger than normal) gap. A plug that has increased resistance demands more from the mag, which, in marginal conditions, can generate a misfire.


I've seen it several times in Barons/Bonanzas at altitude...a plug will start misfiring, but down low will be okay, and will be okay on pressure testing. Often it has high resistance, and when replaced the problem goes away.


(just my dumb country boy understanding, at any rate)
 
In my opinion, Champion stuck it to us as pilots for FAR too long, pretending there was nothing wrong with their plug design, refusing to acknowledge the issues with their plugs, and pooh-poohing the resistance tests that Tempest, Mike Busch, George Braly and many others in the industry were advocating.

Then recently they very quietly released a brand new plug design with a much better resistor design that is far less prone to cracking and shorting. Now they are no longer quite so adamant in claiming that the resistance tests are bogus.

You do the math...

Me – I'll just stick with Tempest plugs, since they haven't had the same issues and generally cost less.
 
Firepilot said:
Steve, I have had the experience of plugs (Champions) in a Husky that ran a bit rough...still ran, but just wasn't as smooth as desired. Resistances were upwards of 50Kohms on several of the plugs. They all passed testing with pressure tester. I replaced them with Tempests, and the roughness went away. (perhaps of interest, the EGTs had slight variance with the Champions).

In discussion with George Braly of GAMI, they have found a lot of problems with high resistance in plugs that pressure tested okay, but would misfire at altitude. (see https://taturbo.com/frames.html).

It makes sense in the context of Ohm's law....P=EI, I=E/R. As Resistance goes up, the amount of voltage required to generate enough power for the spark to jump the gap of the plug goes up as well. (exactly why the guy you helped had a problem....at low engine rpm, the mags weren't generating enough voltage for the spark to jump the (larger than normal) gap. A plug that has increased resistance demands more from the mag, which, in marginal conditions, can generate a misfire.


I've seen it several times in Barons/Bonanzas at altitude...a plug will start misfiring, but down low will be okay, and will be okay on pressure testing. Often it has high resistance, and when replaced the problem goes away.


(just my dumb country boy understanding, at any rate)
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Had a similar problem with a j-3. Between the plugs and the owner trying to adjust the mixture on a stromburg and forgot to tell me.


Sent from my iPhone using Tapatalk
 
Plenty of failure points between the mag drive gear and the spark plug tip, the spark plug is the easiest to replace and likely gets the blame for other problems up the chain. I'll stick with my tried and true pressure test, it has worked fine for me for over 40 yrs. As far as brands go, I'll install whatever flavor the customer wants, they all work fine with hot mags timed properly.
 
I guess it is hard for me to see a spark plug passing a pressure test on my spark plug tester and failing an ohm test. Maybe I will find one.
 
stewartb said:
The best aircraft spark plugs are automotive spark plugs. ;)

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Sent from my iPhone using SuperCub.Org mobile app
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x2

103be702a90e8af691d97496e603c61a.jpg
 
Nope, but that's a testament to archaic regulations, nothing else. Maybe someday the government will get out of the way of private owners. My Cessna motor could be SO much better.

My Cessna uses Champion plugs and Slick mags. They've served me well. I couldn't care less what the internet thinks of either. But still, my initial statement is the truth.
 
Been working on to many Carbon Cubs with Lightspeed ignition. If there is an issue with the coil pack, terminal comes lose etc, the plug is trashed. Easy to replace but threw another element into the troubleshooting procedure after you figure out you have multiple issues. I find very few spark plugs related issues with certified engines but it does save time to throw the old ones in the trash and install new instead of cleaning and testing the aircraft versions
 
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