What were Champion J-3 plugs used for in Flatheads? Racing only? Is there a difference between the newer Champion H10C vs. the older Champion H10? The H10C also carries a Champion number of 844. I believe that H10 style plugs were 7/16" reach plugs for iron heads and aftermarket aluminum heads need 1/2" reach plugs, correct? Has anyone used NGK B6L or Autolite 216 plugs?
Ran H10 for years. Just switched to Autolite 216 on Saturday. will see how she roll's. Posted using the Full Custom H.A.M.B. App!
Recently have had much better performance using the NGK B-6 or B-4 plugs. Also found the Autolite 216 to be better than the H-10C. Seems the now made in Mexico Champion H-10C plugs are not like the Champion H-10 plugs of old made in the USA the new plugs to me suck.
The new Champions suck for sure! When I was running a flathead in my coupe, the plugs would turn black and sooty almost instantly- one short trip up the road and they looked awful. Tried a couple different carbs and adjusted them numerous times because I thought it was running rich... Ended up going to Autolite 216's and boy, what a difference! Plugs never got sooty for the 400+ miles I ran them (obviously not a long term test, but it was certainly alot better then Champs!), and it seemed to run better with the Autolites...
Very interesting - and good to know. I've been running the new H10c plugs and over-leaned the mix cause the plugs looked sooty. The plugs still looked sooty with the lean mix but the exhaust front pipes turned blue! Real lean but not real clean! Richened up the the mix and the motor runs back how it should - plugs still black though. Might try these other suggestions....
I stopped using Champions in anything except lawn mowers back in the early 80s. I worked as a motorcycle mechanic back then. Anytime anything came in wit starting or running problems the first thing I checked was what plugs were in it. If they were Champions, they went in the trash and new NGKs went in. That solved about 90% of the issues.
What plug would you run if you were going to be running a blower? Would you still use the Autolite 216 or NGK B6L or should you go one step colder? If one step colder, then what would be the correct part number to use?
Back when I worked at the motorcycle shop.....blue pipes was caused by a rich mixture. From running with the choke on too long. You sure you are leaning it out?
Edelbrock website says to use the Champion RC12YC with their later model (1949-1953) 1115/1116 aluminum heads. This plug has a .75" or 3/4" reach.
Yep sure. Ran #40 jets for a short while trying to lean the thing off to get cleaner plugs. Put #45 jets back in it when I saw the plugs were still sooty. I run that old car pretty hard at times and that lean condition combined with 95 RON gas sure got the front pipes hot alright. Even burnt the paint off the headers with the smaller jets and it hadn't done that before. I've not had any issues with how the engine runs - it's just that the dark plugs lead me to think it was running a little bit rich with #45s but it was probably okay. So I will try one of these other plug brands when it's time to change out the plugs in a while - just to compare.
rh,...I'm using NGK , and have no problem. As said above, the H10 are too short for aftermarket aluminum heads. 4TTRUK
I have the Ngk now, and believe me, it run much better with Champion or autolite...don't know why, just a fact.
I'm using NGK B5H S with Offy "400" heads. Same heat range as H10, and with proper reach. Hope that helps..... Happy Roddin' 4TTRUK
You cannot tune by plug colour ( or exhaust pipe colour) anymore, with the fuel they are selling us in New Zealand. It doesn't matter how rich or lean the engine is running, the plugs will still be black. It is the synthetic crap they mix at Marsden Point and call petrol....Especially bad with older engines... (pre EFI and high compression lean burn etc. ) I use a gas analyser and a proper large screen tunescope, and even when the mixture is spot on the plugs are black inside 100 miles. I agree though the Champions don't seem to handle the crap fuel well. I have a lot of NOS Champions from my old gas station and they are no better than the new ones... Bosch are better along with NGK and Denso, but Autolites are the best I have run in recent years....we use them in The Phoenix too. Some British (twin cylinder) bikes are getting less than 1000miles from a set of plugs before the performance drops so badly they can hardly run....as I said before it's the fuel not the plugs.
It is the fuel that's changed and not the plugs but changing to a hotter plug, not necessarily a different brand, will usually solve fouling problems. Most old engines need a hotter plug than was originally specified to run well on today's fuel. Choose a thread reach to suit your heads but be wary of projected tips in flatheads as the valves can hit them, especially if you have a high-lift cam. In the NGK range, 5 is usually the correct heat for a flathead, maybe 4 for a gently-driven stocker. I need to run 4s in my aluminium-headed Model A to keep them clean. Don't forget that a lower number means a hotter plug in the NGK brand and Champions are the opposite. Christom, black, sooty plugs don't necessarily mean too rich, it can also mean plugs too cold, so try going back to your optimum jetting and try running NGK 5s or Champion 12s to cure your fouling. I see no point in whingeing about modern fuel. It is what it is and no amount of complaining by old-car people will change that. Adapt, brothers, adapt. It usually just involves a change of heat range and you'll be enjoying the benefits of a lead-free world where spark plugs and exhaust systems hardly ever need replacing, not to mention reduced engine wear.
Yep - totally agree with what you're saying - and yes I do realise sooty plugs can mean they may be a bit cold as opposed to just a rich mixture etc. At least they are not oily! Fairly early days with running this car setup so I'm still getting to know what it likes best. I've gone back to the original setup with mixture etc - including the H10 plugs I put in at the start. I will definitely give the slightly hotter NGK plugs a try once I've burned a few more tanks of fuel.... The car hasn't ever run bad or anything - it was just an observation I made through a curiosity look at the plugs a while back. Good to share info about all this stuff - always learning!
Wondering what the options are for plugs for my 60hp, been running champion j8c plugs. Runs ok, but they do get dark fairly quick. Changed over to ngk's in my MG's a few years ago. I'd just like to maximize my options. Thanks, Marvin,ct
I had Jere Jobe put together my intake and carbs. I have stock heads on '49 8BA. He said he uses the NGK B6HS plugs gapped at .028 and had never had any problems.
I run b6l ngk (thanks to advice from v-8 bob), I drive the roadster a lot and these plugs last all year (maybe more, but I change them every year)...had to change the champions a lot...also what helped me was advice from uncle max on jets and power valve set ups...tell him what you are running and he'll give you the good combo.
My '47 Merc flathead (original cast iron heads) is currently running a 50/50 mix of Champion H10C and NGK B6L. Even with the carb leaned right out, both plug types are fouling out real quick. After as little as 10-15mins at idle the plugs are sooty as hell. When looking at the plug construction compared to a hot plug you might find in a late model car, the most obvious difference is the way the insulator is completely recessed into the plug body (and therefore not exposed directly to the cleaning effects of hot exhaust gasses). Out of pure frustration, yesterday I tried a little experiment with a spare set of H10C's and cut the plug body back (about 1.5mm)to the bottom of the threads, thereby exposing the tip of the insulator. They definately ran cleaner for longer, though still fouled eventually. I've read in any number of forums that NGK plugs are better than Champion at handling fouling issues, and that the B6L is the same heat range as the H10C. I might swap the old plugs out today for a set of NGK B4L and see how it goes. More plug heat's gotta help burn that soot off. Interesting to hear about the crappy NZ gas too. Would it be better to run on 96 octane than the 91 everyone buys at the pump these days?
Although my engine has not been run yet I opted for the Autolite 216 after much reading. A big plus to the autolites' is the black metal body and electrode tip which gives the plug a sort of vintage look.
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