What Champion Plug ru Using in you 340?

[Newbomb Turk]

The question is how long the electrode functions before before it loses efficiency. There's a reason that new vehicles go 100,000 miles between plug changes, but I guess if you don't drive your car much (if at all) it doesn't make a difference..

Right. If you are a cheap skate that makes sense.

They are a ***** to fire, and copper to rare earth they don’t read the same.

If you need to go 100k on your plugs you are in the wrong hobby.

Ask the Autolite guys what a ***** it is to fire those clunkers.the center wire is harder than the NGK and the Champion. The Champion is the softest. They were designed that way for a reason. To make them easy to light.

Much less load on the ignition system and far less misfires compared to NGK and Autolite.

If you can’t spark mark the center wire the plug is too hard, the ignition is junk or both.

 

[ch1ll]

I always use champs in mopars.
I tried other brands and they ran like ****. I also tried different heat range champs than the recommended and they ran like ****.
It started to get hard to find 9's in the late 70's around here where I live, but now there's the internet. For a while I ran a set of Accel plugs and they ran good.

If your engine is wilder than stock, run what Turk tells you.

 

[340six]

View attachment 1716490574View attachment 1716490575View attachment 1716490576
I always used to use champ in mopars
I tried other brands and they ran like ****. I also tried different heat range champs than the recommended and they ran like ****.
It started to get hard to find 9's in the late 70's around here where I live, but now there's the internet. For a while I ran a set of Accel plugs and they ran good.

If your engine is wilder than stock, run what Turk tells you.

Few months ago I was looking at an older youtube that 318Wilrun has. Someone sent him some Champion Since they did not like um. His application did just fine with um. I got a pile of um at less than a buck. Think it was 79 cents. Gud enough fur me. I have over spent in the hobby so it's run what ya got. I also have little over a 120 oil filters most are private label Wix. It was all old stock at 70 ish bucks for a 150ish filters. So ya know what I am gonna use.

 

[str12-340]

Right. If you are a cheap skate that makes sense.

They are a ***** to fire, and copper to rare earth they don’t read the same.

If you need to go 100k on your plugs you are in the wrong hobby.

Ask the Autolite guys what a ***** it is to fire those clunkers.the center wire is harder than the NGK and the Champion. The Champion is the softest. They were designed that way for a reason. To make them easy to light.

Much less load on the ignition system and far less misfires compared to NGK and Autolite.

If you can’t spark mark the center wire the plug is too hard, the ignition is junk or both.

I should have known better than to respond to anything that you post.

 

[340inabbody]

If it’s a street/strip car I try as hard as I can to use an extended tip plug for several reasons.

One, the extended tip is hanging out a bit further and it gets a bit more fuel on it to cool it at WOT.

You can (often but not always as this depends and several factors) run a heat range hotter with the extended tip. At WOT the plug is cooled by a bit more fuel and loafing around it runs a bit hotter.

You can (again usually but not always) run a couple of degrees less timing with the extended tip plug. It moves the plug further into the chamber.

And the C61YC has a full ground wire. It’s hard to do NA (but I’ve done it when I’ve screwed up) but the full length ground wire will start to melt so you have a better chance of seeing the wire start to deform. When it does you know you are about to eat a poop sandwich.

The C63CX plug has a shorter tip so it’s less likely to give issues at WOT but you need a bit more ignition to make them happy.

Because the plug is shorter you may need a couple of degrees more timing.

Because it’s not getting as much fuel on it, it will be hotter at WOT.

Don’t let the range numbers confuse you.

The 61 is colder than the 63 but it’s further in the chamber.

On the dyno I usually end up a range or two colder on plug because the dyno loads the engine differently. It’s like a jet boat kind of.

If I were you I’d start with the 61 and if that’s too cold go to the 63.

You used to be able to get a C63YC but I’m not sure they make them any more.

You can also see if the C63C is still available.

It blows that all these plugs are being eliminated.

C6C and C6YC are not included on Champions site. Only the C61YC=794

Without the other plugs it doesn’t seem like I can use just the 61 if I can’t go up and down the heat range. I need to be able to tune. I am not familiar with Champions race line at all.
Champions web page sucks. No product charts. No information at all. It’s all marketing.

 

[Newbomb Turk]

I should have known better than to respond to anything that you post.

Probably so. You are wrong.

 

[Newbomb Turk]

C6C and C6YC are not included on Champions site. Only the C61YC=794

Without the other plugs it doesn’t seem like I can use just the 61 if I can’t go up and down the heat range. I need to be able to tune. I am not familiar with Champions race line at all.
Champions web page sucks. No product charts. No information at all. It’s all marketing.

At some point, when some…hold on I’ll say it like this so no one gets offended in one of the buy outs of Champion they forced the use of stock numbers rather than plug numbers. That blows because I can easily remember the plug number but not the stock numbers.

The warehouse types and bean counting people need stock numbers, not the end users.

Let me see if I can find the actual stock numbers of the plugs so you can see what’s out there.

The day is coming and is about here when I will be forced to use the NoGoodKind or Autolite’s and live with it.

I rue that day.

 

[340inabbody]

C63cx is 298 no longer available

 

[340inabbody]

C61yc is 794

 

[340inabbody]

C63C is 691 no longer available

 

[Newbomb Turk]

C63C is 691 no longer available

This is certainly problematic. Especially for me.

 

[340inabbody]

I was running Autolite 65 and just installed the 64. I just was ready to cut over to Champions. But Champions are confusing me. At least I can read the Autolites they are available everywhere and the heat range is linear.

 

[340inabbody]

Looks like Champion is no longer supporting this type of line. We are losing drag strips the hobby is getting more and more expensive. I need to win the lottery really badly!

 

[Newbomb Turk]

I was running Autolite 65 and just installed the 64. I just was ready to cut over to Champions. But Champions are confusing me. At least I can read the Autolites they are available everywhere and the heat range is linear.

If I have the choice I’d do the NGK over the Autolite. Let me see if I can find anNGK plug that I’d use for your stuff. I might as well because it sounds like I’ll be doing that for my garbage when I’m out of Champions.

 

[Newbomb Turk]

And here is why I hate doing a cross reference.

A C61C is an NGK R5671-9 and a C61 is the NGK R5686-8.

The second plug is the same heat range in a Champion but in the NGK it’s a range hotter. You end up buying more plugs because you have to sort out the heat ranges.

I need to find my NGK catalog.

 

[340inabbody]

“If I have the choice I’d do the NGK over the Autolite”

Because the NGK copper is softer hence easier start up?

 

[dibbons]

RN9YC is what I run in my recently rebuilt 340 (before and after photos). I ran N9Y in my 273 bracket racer back in the '70's as well.

 

[340inabbody]

RN9YC is what I run in my recently rebuilt 340 (before and after photos). I ran N9Y in my 273 bracket racer back in the '70's as well.

View attachment 1716490615

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Do you have it running yet? What is your CR and dynamic compression? What gas are you using? Timing all in is?

 

[dibbons]

Do you have it running yet? What is your CR and dynamic compression? What gas are you using? Timing all in is?

I have it running but not driving (still working on throttle linkage/kickdown linkage). Initial timing is 10 BTDC and total timing 35 BTDC (with vacuum advance disconnected). I'll be using premium, but not sure what is currently in the fuel tank. Pistons are .040 cast aluminum flat tops with four small valve reliefs. I did some CC work and deck clearance a long time ago but need to find my notes to estimate a compression ratio.

 

[dibbons]

What is your CR and dynamic compression?

Assuming my measurements are close to correct:

 

[Newbomb Turk]

Because the NGK copper is softer hence easier start up?

No because I believe the Autolites are copper too. It’s something else about the way they blend the metal to get them harder.

So I just went 5 rounds with the NGK catalog. I detest their low IQ nomenclature but it is what it is.

So…if I were you I’d start with an R5671A-8 and tune from there.

That 8 looks like it falls between a 65 and 63 Champion.

Of course, reading heat range in an NGK is different from Champion. What I would consider a hot looking plug with a Champion would be pretty close with the NGK.

It’s a nasty learning curve.

So I’d start with the cold plug and if you have to you can go hotter. Better that than the other way around.

Which means if the 7 is still too cold then you need to get out of the “racing” plugs and go back to that crazy street plug numbering system where you can get a 6 heat range. I’d be surprised if you are 12:1 that you’d need a 6 but in the wacky world of NGK you might.

 

[Newbomb Turk]

Assuming my measurements are close to correct:

View attachment 1716490618

Those pistons are .017 proud of the deck?

 

[dibbons]

Those pistons are .017 proud of the deck?

That's what my notes are telling me (it was years ago I was measuring this stuff). On the other hand, I could have just plugged in blueprint specs I found elsewhere (can't remember for sure).

 

[4spdragtop]

Not sure if accurate or not.

 

[340inabbody]

Not sure if accurate or not.

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I saw this as well. Helpful if accurate. Not sure why Autolite isn't on there while Pulsar is.