Champion -v- Unison Spark Plug Comparrison

Geico266

Geico266

Touchdown! Greaser!
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Geico
I helped work on a Christian Eagle, IO-360 that was running rough. The engine was just overhauled due to a cracked crank flange from hard acro. They changed out the crank and rebuilt the cylinders. We just got the engine mounted and new Whirlwind prop installed and the pilot took it for a fly. He was out about an hour on it with it started to run rough.

The engine was running so rough the pilot didn't think he would make the airport. :eek: We pulled the cowl and plugs. Cylinders 1 & 4 were oil soaked. :confused:

Long story short the Champion plugs had a resistance so high the plugs were not firing! They would not even move my meter. We had to find an ultra sensitive one. The Unisons OHMed out at around 1,000 and worked perfectly when we installed them into the engine.

It took the running engine a couple of minutes to "clear" the oil and unused fuel out. The pilot took the plane around the pattern and could not believe the difference! A happy customer, and relieved he made it back to the airport!

Anyone else think Champion plugs suck? :dunno:
 
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I like the Tempest plugs in the 310.
 
Ted DuPuis said:
I like the Tempest plugs in the 310.
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Tempest bought Unison / Autolite.

I agree, I run Tempest fine wire in all my planes needing massives. ;)

Champions plugs increase resistance over time. Hard starting, poor performance, missing. They are junk!
 
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Champion's resistor (inside the plug) is a loose little thing held in place by a small spring. Its contact areas seem susceptible to fouling somehow. If you take the screw out of the plug barrel (of a good plug), then the spring and resistor, and put it all back together, it probably won't fire. I don't know why.

Tempest/Unison copied the old Auburn plug design with its molded-in-place resistor. Makes no trouble. Still, Auburns were better than their newer clones, IMHO. Champion bought them and shut them down. They should have replaced their line with the Auburn design.

Whenever I can I like to replace REM38s or 40s with REM37BYs. Their extended electrodes can't foul with lead.

Dan
 
It's becoming a more and more well known situation that Champion has a huge problem with their plugs. But they have enough died-in-the-wool Champion fans that they don't seem to give a hoot. It has been well documented on other forums, at Oshkosh and by Mike Busch with the facts. No wonder Tempest has put out a little device that checks the resistance of plugs. Jon had one on the counter at Sac Sky Ranch.
After hearing the issues at Champion from their guy at Osh I just gave up on them. Their focus is elsewhere.
 
I installed Tempest UREM37BYs for the first time after my Champions prematurely wore out. Last Sunday I pulled and cleaned them. Not a single one of the dozen was fouled with lead. They seem to live up to the claims compared to the 40's in terms of lead buildup.
 
iflyvfr said:
I installed Tempest UREM37BYs for the first time after my Champions prematurely wore out. Last Sunday I pulled and cleaned them. Not a single one of the dozen was fouled with lead. They seem to live up to the claims compared to the 40's in terms of lead buildup.
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Another vote for the UREM37BY plugs. I ran them in my old Cherokee and when I bought the RV6, I swapped out the 250 hr Champions right away for a set of new Tempest UREM37BYs as soon as I could.
 
I wonder why the FAA doesn't get involved? :confused:

Seriously, the Champion plugs about took the plane out of the air! :eek:
 
I've used Champion plugs for years in my c172 and PA32-260. Cleaned and gapped them at every oil change and annual and bomb test at each annual.

This year was different (currently doing my annual on my Six). My IA checked the gap, cleaned and tested the spark on all 12 of the REM38E plugs and they all did "ok". He checked the resistance and they were all WELL over 5000 ohms. He uses the Tempest resistance tester which maxes at 5k, so he wasn't sure just how high they were. We tested them with a VOM and they tested well into the 20k and 30k range. A couple of them actually reached 6 million ohms! These plugs were new in 2007 with about 600 hrs on them.

After listening to his advice and lots of reading on my own I am DONE with Champion plugs! I just ordered 12 UREM38E (massive) plugs.
 
Chris Mitchell said:
I've used Champion plugs for years in my c172 and PA32-260. Cleaned and gapped them at every oil change and annual and bomb test at each annual.

This year was different (currently doing my annual on my Six). My IA checked the gap, cleaned and tested the spark on all 12 of the REM38E plugs and they all did "ok". He checked the resistance and they were all WELL over 5000 ohms. He uses the Tempest resistance tester which maxes at 5k, so he wasn't sure just how high they were. We tested them with a VOM and they tested well into the 20k and 30k range. A couple of them actually reached 6 million ohms! These plugs were new in 2007 with about 600 hrs on them.

After listening to his advice and lots of reading on my own I am DONE with Champion plugs! I just ordered 12 UREM38E (massive) plugs.
Click to expand...

Resistance is supposed to be between 1000 and 5000 ohms. Some ohmmeters, pirmarily digital meters, use tiny currents for measuring resistance and in some situations will read high and sometimes erratically. I've encountered this when measuring alternator field resistance. The old analog meter will read correctly and steady. Its higher current seems to break through minor resistances that might be in the way. Surface moisture or the tiniest bit of oil comes to mind.

Still, Champion recommends somewhere in their literature that plugs be replaced every 50 hours. No kidding; I actually saw that. Auburn, on the other hand, warranteed their plugs for 400 hours and we often got 1000 or more out of them.

Dan
 
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Chris Mitchell said:
These plugs were new in 2007 with about 600 hrs on them.
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If you got 600 hours out of a set of massives, then you did okay. I never get over 500 before they're footballs. I installed new Tempest plugs in April, my champions had 350 hours on them and had seen better days. They were only 4 years old.

About 50% tested over 25k ohms...and since Dan mentioned it...this was with a good ol' Sperry analog multi-tester that's probably almost as old as I am.
 
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Champions, with their rubbish resistors, are best junked. I had about a 100% failure rate on the resistors. And I was testing them with a high voltage tester, not a DVM.

I moved to Tempest, URHS38S, and the resistance is totally stable.
 
peter-h said:
Champions, with their rubbish resistors, are best junked. I had about a 100% failure rate on the resistors. And I was testing them with a high voltage tester, not a DVM.

I moved to Tempest, URHS38S, and the resistance is totally stable.
Click to expand...

It is amazing to me that Champion is still allowed to make plugs that go into certified airplanes. They are junk.
 
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