I got a hold of some new old stock Champion-X plugs and replaced my Motorcraft F11's with them. I expected increased power and smoothness, but got the opposite. Idle was rough, with frequent skips and acceleration was anemic. Glad I didn't toss the F11's. They're re-installed and the car is back to its old, smooth, spritely self.
Better send 'em to me, Bob.
Are you sure they are clean and gapped right? They should work fine.
Norm
Bob, I found that neither T will run very well with the suggested .025 gap. I found that they both run best at .028 or .029.
Stephen
Bob,
Did you perhaps take them apart since they are 'take-apart' type and you were curious? They have to be tight enough to prevent an air gap yet not tight enough to crack the porcelean.
This past year I saw an outside spark jumper on NIB fresh X's. Took it apart, polished everything, outside 'jumper went away.
Yeah I know, too much space to jump, coils would have to be way too hot, etc. but once you see it...you believe it even with coils set on HCCT painstakingly to get equal!
Put them in and try at dusk...see the lightning show on any plug and either seat them up or return them before you break them. Also, try the screwdriver test even if you don't see a 'spark jumper'. No change in RPM on shorting brass connector to block...you got-um dead plug.
Give them another chance, I do think you'll like them. For most driving a plug is a plug and it really almost doesn't matter IMHO...but if you have a #1 that wants to burn cool, nothing like an 'X' to never have to worry when you are going to have to swap out #1 to get home...provided you do rich/lean correct.
I spent years trying to prove the 'hotter' theory 'bunk and then bought a car that would only run good, clear, and clean with an X in place on #1 all other being equal. For grins and giggles, I put A-25 in the others as a convernsation piece...and since one of the others is a bitsey to begin with, it gets one of each and ran absolutely fine. But arrogant as this may sound, I would not hesitate to put X's in all 4 and for the two cars I redid last summer for others, and the one I did for myself, went with X's all the way around on a just because basis and other then finding a 'spark jumper' on one plug at install...no complaints from anybody since.
BTW...I gap at 0.030 to start with nice tuned coils whether old/old or modern X. I think that old 0.025 number was based on some allowance for weaker used coils.
Open the gaps up to .035 and see if that does the trick. I had the same problem until I opened them up. Now they work great.
Mine are at .030 also. I tried .025 and got zilch.
I am at the upper edge myself.
With the coils properly rebuilt & calibrated, the engine will run best with the .025 spark plug gap on the Champion X Plugs.
I'm running Edison #14 plugs with .025 gap , engine starts easy & doesn't miss at speed.
Maybe the Fun Projects coil box kit has something to do with good ignition ????
Bob Jablonski
Might add that the .025" gapped plugs run best on magneto powered ignition.