Spark Plugs (Cleaning/Servicing reminder)

[170C]

Kyle, some 450+ hours ago (July 2006) I replaced my old Champion plugs (after mag overhauls they ran really bad) with Unison plugs. I have been well satisfied with those spark plugs every since. At my most recent annual in April they still looked good with no football electrodes. I have not tried checking each plug as has been recommended in other posts, but I plan to continue using these spark plugs until they either show extreme wear or the ole Continental starts not running smooth. What will I replace them with? Not sure. Will see what results others report with Tempest and Champions.

[blueldr]

It's unfortunate that our fearless federal friends require that we are limited to using the ridiculously expensive spark plugs that they have approved. Strangely enough, the experimentals mostly seem able to make automotive spark plugs work just fine. You can buy a set of twelve for about the price of one fine wire aircrafrt plug.
In fact the whole ignition system is terribly outdated. When was the last time you had an automotive ignition system failure, or replaced the spark plugs, with a modern automobile ignition system.
How efficient would an automobile engine be if the ignition fired at 25 deg. BTC no matter what the running condition was. You can buy a brand new Cirrus airplane and the ignition system is almost as sophisticated as a Model A Ford except that you have no control over the spark advance.

[marathonrunner]

Based on the 200 to 400 hours and they need replacement I would for sure only use fine wires. The ohm test is a good way to check as well. Also there is a go no go gauge that is usually free at trade shows for AFTER you gap your plugs. If they go through the hole they are beyond limits.

[blueldr]

Not to mention, when was the last time you sent your automotive ignition system in for a 500 hour overhaul for a few hundred bucks?
I have two Fords, a '96 and a '99, with 4 liter V-6 engines, each one having over 150K miles, and neither has ever had any work done on their ignition systems.
When I was a little kid, my dad had a 1916 Hupmobile with an Atwater Kent ignition system utilizing a rotary ignition switch. This switch was desigined to reverse the polarity of the ignition system each time it was roated 90 degrees clockwise to turn it on. See, they even knew about polarity wear way back then.

[GAHorn]

...When I was a little kid, my dad had a 1916 Hupmobile with an Atwater Kent ignition system utilizing a rotary ignition switch. This switch was desigined to reverse the polarity of the ignition system each time it was roated 90 degrees clockwise to turn it on. See, they even knew about polarity wear way back then.

Geesus....NOW I understand you a lot better!