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Spark Plugs -- Massive or Fine Wire


MisfitSELF

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1 hour ago, Bob_Belville said:

And from your fairly limited personal experience you conclude and declare that anyone whose experience is the opposite is nuts? :rolleyes: (ISTM that line of reasoning is more appropriate to religion or politics where we get to hold tight to our own version of reality and write off the other guy as a heretic or a communist.)

I did not call anyone nuts, if the engine is in good shape, averse operational impacts are more defined by the operator (loose nut) vs. the engine.  Finding, recording, illuminating operational impacts to equipment is my day job, so I would not call my experience "fairly limited".

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1 hour ago, Bob_Belville said:


In my personal experience fine wires are cheaper than massive. In cost per hour, of course.


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I don't know. I will clean and re-gap my plugs until there is no metal left. I have probably gone through 3 sets of fine wires and 5 sets of massives. They seem to last about the same number of hours. Most people throw away massives when they have a lot of life left in them. I usually get around 1000 hours out of plugs. I will admit I'm not great about logging every plug I clean and replace.

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I am sure that fine wires are superior. I doubt they are 3 times as superior. To read how people feel about them, it’s a wonder piston aero-engines were able to achieve any sort of dispatch reliability before fine wires were introduced.  I operate a simple IO360. I run massives. Currently all are new gen Champions but I am replacing 4 with tempest massives. Fine wires answer a question that my engion has never asked.

With massives it:

does not foul plugs

is not hard to start (hot or cold)

goes through plugs about every 800-1000hrs.

runs smoothly across the mixture spectrum.

will go way further lean of peak than I want or need.

 I’m sure the above would be true with find wires as well. I would buy them if I thought I would notice their superiority beyond my wallet.

I know that our ignition systems are primitive by modern standards but they are still robust and redundant duel ignition sources. A well-maintained ignition system should run beautifully with massive plugs.

Edited by Shadrach
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3 hours ago, Igor_U said:

I'd be really curious how often this happens and what others would do.

I lost a center electrode on a Tempest FW. During the search for the electrode--borescope, oil change--there was evidence of it bouncing around in the cylinder before escaping. We didn't find the electrode in the engine or oil but several A&P's were of the opinion that it escaped via the exhaust, as it was too large to get past the multiple piston rings. I've had two oil changes since and there was nothing but carbon in the oil when strained. I agree with my A&P's assessments that it escaped via the exhaust. Tempest sent me a replacement plug but did not tell me if they were going to conduct a failure analysis. If Tempest did, I would doubt they would share the report. 

I've got 62 hours on the new plug and close to 200 hours on the others. Time will tell regarding their longevity but I now have a spare, just in case. I would buy them again, as I had fouling problems with my Champions. My engine ran smoother, hot started easier, and I've yet to foul one. 

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54 minutes ago, Shadrach said:

I am sure that fine wires are superior. I doubt they are 3 times as superior. To read how people feel about them, it’s a wonder piston aero-engines were able to achieve any sort of dispatch reliability before fine wires were introduced.  I operate a simple IO360. I run massives. Currently all are new gen Champions but I am replacing 4 with tempest massives. Fine wires answer a question that my engion has never asked.

With massives it:

does not foul plugs

is not hard to start (hot or cold)

goes through a plugs about every 800-1000hrs.

runs smoothly across the mixture spectrum.

will go way further lean of peak than I want or need.

 I’m sure the above would be true with find wires as well. I would buy them if I thought I would notice their superiority beyond my wallet.

I know that our ignition systems are primitive by modern standards but they are still robust and redundant duel ignition sources. A well-maintained ignition system should run beautifully with massive plugs.

The only reason I got the fine wire plugs was when I was having problems with hard starting, I wasn't sure the plugs would help so I only changed the left mag plugs.  That turned out to be a weak left mag, so I'm glad I didn't change all eight.

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1 hour ago, jaylw314 said:

The only reason I got the fine wire plugs was when I was having problems with hard starting, I wasn't sure the plugs would help so I only changed the left mag plugs.  That turned out to be a weak left mag, so I'm glad I didn't change all eight.

Starting problems can be caused by a wide range of issues.  Throwing parts at the problem will eventually work but probably not the best course of action!   You likely could’ve had your mag IRAN’d for the price of four fine wires.

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Wow, this is really interesting. I must admit, I never thought that much about spark plugs.

As I mentioned earlier, my experience with fine wire plugs is mainly with radials (R-985 on Beavers I fly for a seaplane company, R-1830 on a DC-3 I help maintain and sometimes fly for a museum, and an R-2600 on a B-25). On my personal aircraft, I've always used massives. 

Lot's of comments about improved performance from those who have switched to fine wires made me wonder if I'm missing something. I did some research and here's what I've found.

1. No manufacturer of fine wires touts a specific, measurable benefit beyond longer life.

2. Recommendations are to remove, clean, check gap, and rotate every 100 hrs regardless of plug type, so the maintenance is the same.

3. The only strong recommendation I could find was from RAM with a claimed measured 2% drop in SFC on a specific turbocharged engine. As an engineer, 2% seems within the margin of measurement error and I would want to see the data. http://www.ramaircraft.com/Maintenance-Tips/Spark Plugs-Fine-Wire-vs-Massive.htm

4. Many have stated that the fine wires are 3X cost with 3X life, so the operating cost is about a wash.

5. It's clear that fine wires may help with engines near needing a top overhaul that have an issue fouling plugs.

For me, I think it's a wash. I note that my previous study of behavioral finance makes be suspicious of expectation bias and confirmation bias in the anecdotal reports. That does not mean that I do not believe that these reports are sincere -- it just means that I await hard data which even the manufacturers of these spark plugs seem unable to provide.

Skip

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1 hour ago, PT20J said:

Wow, this is really interesting. I must admit, I never thought that much about spark plugs.

As I mentioned earlier, my experience with fine wire plugs is mainly with radials (R-985 on Beavers I fly for a seaplane company, R-1830 on a DC-3 I help maintain and sometimes fly for a museum, and an R-2600 on a B-25). On my personal aircraft, I've always used massives. 

Lot's of comments about improved performance from those who have switched to fine wires made me wonder if I'm missing something. I did some research and here's what I've found.

1. No manufacturer of fine wires touts a specific, measurable benefit beyond longer life.

2. Recommendations are to remove, clean, check gap, and rotate every 100 hrs regardless of plug type, so the maintenance is the same.

3. The only strong recommendation I could find was from RAM with a claimed measured 2% drop in SFC on a specific turbocharged engine. As an engineer, 2% seems within the margin of measurement error and I would want to see the data. http://www.ramaircraft.com/Maintenance-Tips/Spark Plugs-Fine-Wire-vs-Massive.htm

4. Many have stated that the fine wires are 3X cost with 3X life, so the operating cost is about a wash.

5. It's clear that fine wires may help with engines near needing a top overhaul that have an issue fouling plugs.

For me, I think it's a wash. I note that my previous study of behavioral finance makes be suspicious of expectation bias and confirmation bias in the anecdotal reports. That does not mean that I do not believe that these reports are sincere -- it just means that I await hard data which even the manufacturers of these spark plugs seem unable to provide.

Skip

Skip,

I guess it should not be too surprising that neither Champion nor Tempest, who both sell both massive and fine wire, are reluctant to go on the record favoring one over the other. Hey daddy who's your favorite child?  

Mike Busch is one source of the 3x the cost, 3 times the life. 

Much of this is basic for many of you but perhaps some will find it useful:

http://www.eaavideo.org/detail/video/1826468805001/webinar--all-about-spark-plugs?autoStart=true&q=spark plug

BTW, I use and like fine wire and your reference to "behavioral finance" and bias are no doubt valid. I would put more weight on the behavior of  @M20Doc who sees a lot of planes, Mooney, Cirrus and others, and put his money on the line to treat that big IO720 to fine wire plugs.

 

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4 hours ago, Shadrach said:

Starting problems can be caused by a wide range of issues.  Throwing parts at the problem will eventually work but probably not the best course of action!   You likely could’ve had your mag IRAN’d for the price of four fine wires.

I did get it IRAN'd and it did cost about the same :D  I didn't feel too bad about it, because I was curious as to whether there would be other benefits.  I do think they help a little bit with cold starts, but nothing else obvious.  In any case, I wasn't losing anything because I kept the old spark plugs

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7 hours ago, PT20J said:

Good feedback, Bob.

Hey Clarence, @M20Doc since you shelled out $2K, can you convince me I should switch to iridium plugs at my next plug change on my new rebuilt IO-360-A3B6? 

Skip

Not really sure I can convince you, I might have more luck with the argument that a Comanche is better than a Mooney!

I did consider the 37BY plugs already mentioned here, but they aren’t approved for the 720.  While the cost of fine wires may be equal on a per hour basis, they do seem to take less time to maintain. With shop labour rates are approaching the cost of a fine wire plug, the saving are real.

I have not flown with the new Tempest plugs as I’m finishing the Annual, but I did notice that the engine was running rougher the last while on the Champion fine wires.

Clarence

Edited by M20Doc
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11 hours ago, Bob_Belville said:

Skip,

I guess it should not be too surprising that neither Champion nor Tempest, who both sell both massive and fine wire, are reluctant to go on the record favoring one over the other. Hey daddy who's your favorite child?  

Mike Busch is one source of the 3x the cost, 3 times the life. 

Much of this is basic for many of you but perhaps some will find it useful:

http://www.eaavideo.org/detail/video/1826468805001/webinar--all-about-spark-plugs?autoStart=true&q=spark plug

BTW, I use and like fine wire and your reference to "behavioral finance" and bias are no doubt valid. I would put more weight on the behavior of  @M20Doc who sees a lot of planes, Mooney, Cirrus and others, and put his money on the line to treat that big IO720 to fine wire plugs.

 

The “They make both argument “ doesn’t hold water. Go to the Mercedes dealership and see if the salesman tries to convince you an S class is the same thing as a C class.  The one fault in the above analogy is that there’s a measurable and testable difference in performance between an S class and a C class.

Edited by Shadrach
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15 hours ago, M20Doc said:

I love them so much I bought a $2000 set!

Clarence

Just think Clarence, if you had come to the Mooney Summit last year, you could have bid on a set in the silent auction! The 4 cyl guys were crying "foul" as they couldnt compete with bids from the 6 cyl guys, and you could have easily walked off with the set of 16 for cheap. Savings wouldnt feed that beast however, not much can :)

 

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I will say that I just got rid of a 2008 for Expedition with 150K miles with fancy plugs that I never changed or cleaned or gapped. in the 10 years of ownership.  If it aint broke, don't fix it.   If the cylinders are getting oily you can go with the BY Champion that has a longer nose on some 4 cylinder Lycomings.

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I’ve used BY plugs since my first annual with no fouling, but I lean aggressively.  I think the discussion should be: BY plugs or fine wire plugs.  Assuming they’re approved for your engine, can anyone come up with a reason to use non-BY massives?

I had a brain fart and dropped a BY plug during my recent annual.  It was a $40Cdn mistake vs a $120Cdn mistake.

One advantage of fine wires would be less potential to have a carbon bridge short.  I had that happen last month.

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While the cost of fine wires may be equal on a per hour basis, they do seem to take less time to maintain. With shop labour rates are approaching the cost of a fine wire plug, the saving are real.

Since plugs are something I can do, I handle maintenance and I work cheap. Additionally the massive plugs seem more tolerant of amateurs like myself.


Tom
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21 hours ago, N201MKTurbo said:

I don't know. I will clean and re-gap my plugs until there is no metal left. I have probably gone through 3 sets of fine wires and 5 sets of massives. They seem to last about the same number of hours. Most people throw away massives when they have a lot of life left in them. I usually get around 1000 hours out of plugs. I will admit I'm not great about logging every plug I clean and replace.

Fine wire plugs go over 2000 hours for a set. I have 650hours on these Tempest fine wire plugs,  and they look new. No electrode wear.  Do not blast them with abrasive media. It’s not needed and it ruins the plugs. 

Edited by jetdriven
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