What are you using ? What works best for just the every day driver and what gap are you using . I have as used of the champion X brand and was going to give them a try.
Edison 14s, gapped at 0.030 (my T runs a Truefire ignition).
I run a NOS set of Xs in mine, no problems, .030" gap, Thomas distributor and standard 6V coil.
When, for reasons of authenticity, I replaced my Motorcraft F11 plugs with Champion X plugs (which you'd think come from Krypton by the way people talk), my engine lost a lot of power and ran rough.
I shrugged off the mild disappointment, re-installed the Motorcraft plugs and disguised them with the shiny brass thumb-nuts that Lang's sells. -Good enough.
Bob, were they NOS Xs or the new repops ?
I have new Champions, either 425s or 525s. Near as I can tell theyíre like an X you canít take apart. The gap is whatever the book calls for and on a fairly tired engine like mine I canít imagine any other plug doing a better job of combusting fuel. I have a brand new set of Autolites I want to try in the spring and if I can still get Motorcrafts over the parts counter Iíll try a set of them too.
The Champion-X plugs I bought were gotten from e-bay and represented as new-old-stock, but the boxes and the wrapping within didn't have the familiar yellowed look of aged paper products. -The pedigree of these supposedly NOS plugs is therefore kind of iffy. -As my Flivver is nowhere near museum-authentic-original, this wasn't much of an issue.
New Champion X plugs are ungodly expensive. Old ones, if properly cleaned and assembled, work just as well and have the advantage of costing a fraction of the price. The least costly new plugs are Autolite 3095. If you want to go X but don't want to spend over a hundred bucks to do it, run the Autolites while you shop for X's at swap meets or on eBay. I might pay as much as $10 for a nice early X, but the common brass hats can be had for $2 to $5.
Champion 25's for 20 years in the Crappy T, a shot engine with a hot Bosch dizzy. Perfect
New (late 70's) Champion X's in the PhsychOdelic T with timer and hot coils. Perfect after he warms up just a bit
The mish-mash (mostly Tigers) in the TT that were there with timer and coils. Purrs like a happy cat until he warms up and then one says no or maybe
Mark & All:
Been running Edison #14's at .025" gap with 6V battery, magneto, and E-Timer at different times..... doesn't miss a beat.
I run original X's in mine. Tried a set of Ward's once, and the car ran like crap.
Old Champions or new Motorcraft. (9 in ten work fine).
Motorcraft will get you down the road as good as Champions.
I have a set of old Wizard plugs from the 40's that came from Western Auto. They worked well. I used them in my 21 Touring and only removed them for a new set of Motorcraft I got at Chickasha for a dollar each. Call me cheap!
I run the champion x repops in both 26- 27 coupes and my 26 rpu has old champion x plugs from the swap meets and they work perfectly. I have ran the new champion plugs with no issues. I like the old 2 piece plugs.