Quick question. Is the gap for Champion 25 plugs .035? Getting ready for our Christmas parade in the morning.
I don't know about Champion 25s, but it has worked well for me with other plugs.
PS Send pictures of Ts in the parade, please!
Thanks Joe, that's what I thought. I will be the only T in the parade as far as I know, will try to get photos.
I used to have a Champion chart in my shope that is now missing that used to say .035. That is what I use on all my plugs.
Thanks Dave...I've adjusted and we are off in a few hours to spread a little T cheer....to heck with those A's that will be present.....
over the years I had always set plugs with the thickness of a hack saw blade which is about right for plugs, more so that they are all the same, an 1/32" or as close to 32 thou is usually book setting on many standard settings.
.035" gap may be OK for battery ignition, & the thin dime gap sounds good ( were dimes thinner ? ) but magneto ignition IMHO shines, when everything else is in order with a .025" spark plug gap..... gives easier cold crank starts & a smoother engine on stock magneto ignition.
Try it for yourself at different gaps. I find the same thing as Bob, .025" gap and Champion X plugs, after that the plugs last seemingly forever without maintenance.
I tried the Champion 25 plugs and could not get good results from them with original T ignition.
Champion sells two spark plugs to fit the model T.
They sell the take-apart X plug (stock number 425) which sells for close to $30.
They sell the one-piece 25 plug (stock number 525) which sells for about $11.
Motorcraft (owned by Ford) sells one spark plug to fit the model T - the F11. It sells for less than $5.
My speedster ran great on the Motorcraft spark plugs just like it did on the Autolite 3095 plugs I replaced. I gapped them at 0.032" which is mighty close to Ford's specification of 1/32" (0.03125").
Autolite was once owned by Ford.
The Autolite 3095 and Motorcraft F11 work well in the model T because Ford made sure they would.
Champion wants you to buy the X plug from them.
That's my story and I'm sticking to it.
The best plugs you can buy are original Champion X. I usually pay $5 or less for them, but I splurged and spent $10 on this one.
If you put in a thermostat, the engine will always run hot enough you won't need those expensive plugs to avoid fouling.
If you put in a thermostat you will decrease your Model T's reliability and do nothing for the spark plugs.
My car had neither a thermostat nor an intake air preheater pipe. My car's engine was completely stock other than the low-compression aluminum pistons and some unknown amount of head resurfacing.
I drove my car for almost three years with the Motorcraft plugs and it never missed a beat so I never had any reason to remove them.
If your engine is not running hot enough, you need hot plugs, like the -X, to make spark in a mixture that's lean enough to give decent fuel economy.
That's one reason to choke a cold engine. The rich mixture fires easier with cold plugs. Think about vacuum tubes: they need a cathode heater to enable electron flow.
The Service Manual specifically states the gap to be 1/32 of an inch.
Your mileage may vary......